Sample records for nuclei particle counter

  1. Rapid Scan Humidified Growth Cloud Condensation Nuclei Counter

    SciTech Connect (OSTI)

    Gregory L. Kok; Athanasios Nenes

    2013-03-13T23:59:59.000Z

    This research focused on enhancements to the streamwise thermal gradient cloud condensation nuclei counter to support the rapid scan mode and to enhance the capability for aerosol humidified growth measurements. The research identified the needs for flow system modifications and range of capability for operating the conventional instrument in the rapid scan and humidified growth modes.

  2. Process Particle Counter | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin of ContaminationHubs+ Report Presentation:in the U.S. by Consider theDepartment ofParticle

  3. Particle-hole symmetry parameters for nuclei

    E-Print Network [OSTI]

    Ian Bentley

    2015-03-10T23:59:59.000Z

    Two parameters, nu and zeta, motivated by particle-hole symmetry are introduced. These parameters are determined using the number of proton (or neutron) particles and holes counted from neighboring shell closures. The new parameters can be used to evaluate particle-hole and proton-neutron symmetries of adopted B(E2) values, which indicate that both symmetries are approximate for A>100. The combined symmetries motivate empirical fits of binding energies and the energy ratio E(4_1^+)/E(2_1^+). A global binding energy fit consisting of a traditional liquid droplet and one new shell term, comprised of a function of nu and zeta, reproduces the experimental binding energies of 2353 nuclei with an r.m.s. standard deviation of 1.55 MeV.

  4. Single-particle states in transcurium nuclei.

    SciTech Connect (OSTI)

    Ahmad, I.

    1999-09-30T23:59:59.000Z

    Identification of single-particle states in the heaviest known nuclei is important because their energies can be used to test the single-particle potential in these high-Z elements. These states can be identified by studying the decay schemes of very heavy odd-mass nuclides. For neutrons, the heaviest odd-mass nuclide available in milliCurie quantities is the 20-h {sup 255}Fm and for protons the heaviest nuclide available is the 20-d {sup 253}Es. These two isotopes were obtained from the Transplutonium Element Production Program at Oak Ridge and their spectra were measured with high-resolution germanium spectrometers. From the results of these measurements we have identified states in {sup 251}Cf and {sup 249}Bk up to 1 MeV excitation energy.

  5. Molecular Gas in NUclei of GAlaxies (NUGA) I.The counter-rotating LINER NGC4826

    E-Print Network [OSTI]

    S. Garcia-Burillo; F. Combes; L. K. Hunt; F. Boone; A. J. Baker; L. J. Tacconi; A. Eckart; R. Neri; S. Leon; E. Schinnerer; P. Englmaier

    2003-06-06T23:59:59.000Z

    We present new high-resolution observations of the nucleus of the counter-rotating LINER NGC4826, made in the J=1-0 and J=2-1 lines of 12CO with the IRAM Plateau de Bure mm-interferometer(PdBI).The CO maps, which achieve 0.8''(16pc) resolution in the 2-1 line, fully resolve an inner molecular gas disk which is truncated at an outer radius of 700pc. The total molecular gas mass is distributed in a lopsided nuclear disk of 40pc radius and two one-arm spirals, which develop at different radii in the disk. The distribution and kinematics of molecular gas in the inner 1kpc of NGC4826 show the prevalence of different types of m=1 perturbations in the gas. Although dominated by rotation, the gas kinematics are perturbed by streaming motions related to the m=1 instabilities. The non-circular motions associated with the inner m=1 perturbations agree qualitatively with the pattern expected for a trailing wave developed outside corotation ('fast' wave). In contrast, the streaming motions in the outer m=1 spiral are better explained by a 'slow' wave. A paradoxical consequence is that the inner m=1 perturbations would not favour AGN feeding. An independent confirmation that the AGN is not being generously fueled at present is found in the low values of the gravitational torques exerted by the stellar potential for R<530pc. The distribution of star formation in the disk of NGC4826 is also strongly asymmetrical. Massive star formation is still vigorous, fed by the significant molecular gas reservoir at R<700pc. There is supporting evidence for a recent large mass inflow episode in NGC4826. These observations have been made in the context of the NUclei of GAlaxies (NUGA) project, aimed at the study of the different mechanisms for gas fueling of AGN.

  6. Ice Nuclei in Marine Air: Biogenic Particles or Dust?

    SciTech Connect (OSTI)

    Burrows, Susannah M.; Hoose, C.; Poschl, U.; Lawrence, M.

    2013-01-11T23:59:59.000Z

    Ice nuclei impact clouds, but their sources and distribution in the atmosphere are still not well known. Particularly little attention has been paid to IN sources in marine environments, although evidence from field studies suggests that IN populations in remote marine regions may be dominated by primary biogenic particles associated with sea spray. In this exploratory model study, we aim to bring attention to this long-neglected topic and identify promising target regions for future field campaigns. We assess the likely global distribution of marine biogenic ice nuclei using a combination of historical observations, satellite data and model output. By comparing simulated marine biogenic immersion IN distributions and dust immersion IN distributions, we predict strong regional differences in the importance of marine biogenic IN relative to dust IN. Our analysis suggests that marine biogenic IN are most likely to play a dominant role in determining IN concentrations in near-surface-air over the Southern Ocean, so future field campaigns aimed at investigating marine biogenic IN should target that region. Climate related changes in the abundance and emission of biogenic marine IN could affect marine cloud properties, thereby introducing previously unconsidered feedbacks that influence the hydrological cycle and the Earth’s energy balance. Furthermore, marine biogenic IN may be an important aspect to consider in proposals for marine cloud brightening by artificial sea spray production.

  7. Heavy particle radioactivity from superheavy nuclei leading to $^{298}$114 daughter nuclei

    E-Print Network [OSTI]

    K. P. Santhosh; B. Priyanka

    2014-04-02T23:59:59.000Z

    The feasibility for the alpha decay and the heavy particle decay from the even-even superheavy (SH) nuclei with Z = 116-124 have been studied within the Coulomb and proximity potential model (CPPM). The Universal formula for cluster decay (UNIV) of Poenaru et al., the Universal Decay Law (UDL) and the Scaling Law of Horoi et al., has also been used for the evaluation of the decay half lives. A comparison of our predicted half lives with the values evaluated using these empirical formulas are in agreement with each other and hence CPPM could be considered as a unified model for alpha and cluster decay studies. The spontaneous fission half lives of the corresponding parents have also been evaluated using the semi-empirical formula of Santhosh et al. Within our fission model, we have studied cluster formation probability for various clusters and the maximum cluster formation probability for the decay accompanying $^{298}$114 reveals its doubly magic behavior. In the plots for log_10(T_1/2) against the neutron number of the daughter in the corresponding decay, the half life is found to be the minimum for the decay leading to $^{298}$114 (Z = 114, N = 184) and this also indicate its doubly magic behavior. Most of the predicted half lives are well within the present upper limit for measurements and the computed alpha half lives for $^{290,292}$116 agrees well with the experimental data. We have thus confidently indicate towards a new island for the cluster radioactivity around the superheavy isotope $^{298}$114 and its neighbors and we hope to receive experimental information about the cluster decay half lives of these considered SHs, hoping to confirm the present calculations.

  8. Self-consistent description of single-particle levels of magic nuclei

    E-Print Network [OSTI]

    N. V. Gnezdilov; I. N. Borzov; E. E. Saperstein; S. V. Tolokonnikov

    2014-04-04T23:59:59.000Z

    Single-particle levels of seven magic nuclei are calculated within the Energy Density Functional (EDF) method by Fayans et al. Three versions of the EDF are used, the initial Fayans functional DF3 and its two variations, DF3-a and DF3-b, with different values of spin-orbit parameters. Comparison is made with predictions of the Skyrme-Hartree-Fock method with the HFB-17 functional. For the DF3-a functional, phonon coupling (PC) corrections to single-particle energies are found self-consistently with an approximate account for the tadpole diagram. Account for the PC corrections improves agreement with the data for heavy nuclei, e.g. for 208 Pb. On the other hand, for lighter nuclei, e.g. 40,48 Ca, PC corrections make the agreement a little worse. As estimations show, the main reason is that the approximation we use for the tadpole term is less accurate for the light nuclei.

  9. Single particle states in the heaviest known nuclei

    SciTech Connect (OSTI)

    Ahmad, I.; Chasman, R.R.; Friedman, A.M. (Argonne National Lab., IL (USA)); Yates, S.W. (Kentucky Univ., Lexington, KY (USA))

    1990-01-01T23:59:59.000Z

    Neutron single-particle states above the N=152 subshell have been studied by high-resolution (d,p) reaction on a {sup 250}Cf target. All of the orbitals between N=152 and N=164 subshells have been identified. A tentative assignment has been made for the 1/2-(750) Nilsson state. 10 refs.

  10. Screening materials with the XIA UltraLo alpha particle counter at Southern Methodist University

    SciTech Connect (OSTI)

    Nakib, M. Z.; Cooley, J.; Kara, B.; Qiu, H.; Scorza, S. [Department of Physics, Southern Methodist University, Dallas, TX (United States)] [Department of Physics, Southern Methodist University, Dallas, TX (United States); Guiseppe, V. E. [Department of Physics, University of South Dakota, Vermillion, SD (United States)] [Department of Physics, University of South Dakota, Vermillion, SD (United States); Rielage, K. [Los Alamos National Laboratory, Los Alamos, NM (United States)] [Los Alamos National Laboratory, Los Alamos, NM (United States); Schnee, R. W. [Department of Physics, Syracuse University, Syracuse, NY (United States)] [Department of Physics, Syracuse University, Syracuse, NY (United States)

    2013-08-08T23:59:59.000Z

    Southern Methodist University houses one of five existing commercially available UltraLo 1800 production model alpha counters made by XIA LLC. The instrument has an electron drift chamber with a 707 cm{sup 2} or 1800 cm{sup 2} counting region which is determined by selecting the inner electrode size. The SMU team operating this device is part of the SuperCDMS screening working group, and uses the alpha counter to study the background rates from the decay of radon in materials used to construct the SuperCDMS experiment. We have studied four acrylic samples obtained from the MiniCLEAN direct dark matter search with the XIA instrument demonstrating its utility in low background experiments by investigating the plate-out of {sup 210}Pb and comparing the effectiveness of cleaning procedures in removing {sup 222}Rn progenies from the samples.

  11. Probing particle and nuclear physics models of neutrinoless double beta decay with different nuclei

    E-Print Network [OSTI]

    G. L. Fogli; E. Lisi; A. M. Rotunno

    2009-08-06T23:59:59.000Z

    Half-life estimates for neutrinoless double beta decay depend on particle physics models for lepton flavor violation, as well as on nuclear physics models for the structure and transitions of candidate nuclei. Different models considered in the literature can be contrasted - via prospective data - with a "standard" scenario characterized by light Majorana neutrino exchange and by the quasiparticle random phase approximation, for which the theoretical covariance matrix has been recently estimated. We show that, assuming future half-life data in four promising nuclei (Ge-76, Se-82, Te-130, and Xe-136), the standard scenario can be distinguished from a few nonstandard physics models, while being compatible with alternative state-of-the-art nuclear calculations (at 95% C.L.). Future signals in different nuclei may thus help to discriminate at least some decay mechanisms, without being spoiled by current nuclear uncertainties. Prospects for possible improvements are also discussed.

  12. Probing particle and nuclear physics models of neutrinoless double beta decay with different nuclei

    SciTech Connect (OSTI)

    Fogli, G. L.; Rotunno, A. M. [Dipartimento Interateneo di Fisica 'Michelangelo Merlin', Via Amendola 173, 70126 Bari (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Lisi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy)

    2009-07-01T23:59:59.000Z

    Half-life estimates for neutrinoless double beta decay depend on particle physics models for lepton-flavor violation, as well as on nuclear physics models for the structure and transitions of candidate nuclei. Different models considered in the literature can be contrasted - via prospective data - with a 'standard' scenario characterized by light Majorana neutrino exchange and by the quasiparticle random phase approximation, for which the theoretical covariance matrix has been recently estimated. We show that, assuming future half-life data in four promising nuclei ({sup 76}Ge, {sup 82}Se, {sup 130}Te, and {sup 136}Xe), the standard scenario can be distinguished from a few nonstandard physics models, while being compatible with alternative state-of-the-art nuclear calculations (at 95% C.L.). Future signals in different nuclei may thus help to discriminate at least some decay mechanisms, without being spoiled by current nuclear uncertainties. Prospects for possible improvements are also discussed.

  13. Particle Concentration Dynamics in the Ventilation Duct after an Artificial Release: for Countering Potential Bioterriorist Attack

    E-Print Network [OSTI]

    You , Siming; Wan, Man Pun

    2014-01-01T23:59:59.000Z

    leads to In this work, the models of particle concentration dynamics in the ventilation duct following a resuspension

  14. Inelastic Interactions of Proton with Emulsion Nuclei without Shower Particle Creation

    SciTech Connect (OSTI)

    Abdelsalam, A. [Physics Department, Faculty of science, Cairo University, Giza, (Egypt); El-Nagdy, M. S. [Physics Department, Faculty of science, Helwan University, Helwan (Egypt); Rashed, N. [Physics Department, Faculty of science, Fayoum University, Fayoum (Egypt); Badawy, B. M. [Reactor Physics Department, Nuclear Research Center, Atomic Energy Authority (Egypt)

    2007-02-14T23:59:59.000Z

    This paper presents exhaustively the general characteristics of the inelastic interactions of P, 4He and 7Li with emulsion nuclei distinguished without relativistic hadrons (ns = 0) in Lab. system. The dependence of these interactions on the projectile and target sizes is presented. It is found that, the probability of the events having (ns = 0) is dependent on projectile size and incident energy. The average no. of grey particles and black particles as well as the ratio / are displayed for different target size. The multiplicity distribution of different target fragments for the events having (ns = 0), ns {>=} 0 and those of complete destruction (Nh {>=} 28) are presented.

  15. Alpha-Cluster Model, Charge Symmetry of Nuclear Force and Single Particle Bound State Potential in Symmetrical Nuclei

    E-Print Network [OSTI]

    G. K. Nie

    2011-06-21T23:59:59.000Z

    A phenomenological alpha-cluster model based on the charge symmetry of nuclear force allows one to estimate the last proton position radius (LPPR) in a symmetrical nucleus. The values of LPPR obtained for the symmetrical nuclei with 5=15 it is inappropriate to represent a single particle bound state by the Woods-Saxon potential. For the nuclei with 5<=Z<=14 the error of the spectroscopic factor obtained with standard parameters in DWBA analysis of pure peripheral one nucleon transfer reactions is estimated. It is shown that for some nuclei using the standard parameters brings an error more than 20%.

  16. Ab-initio approach to effective single-particle energies in doubly closed shell nuclei

    E-Print Network [OSTI]

    T. Duguet; G. Hagen

    2012-04-11T23:59:59.000Z

    The present work discusses, from an ab-initio standpoint, the definition, the meaning, and the usefulness of effective single-particle energies (ESPEs) in doubly closed shell nuclei. We perform coupled-cluster calculations to quantify to what extent selected closed-shell nuclei in the oxygen and calcium isotopic chains can effectively be mapped onto an effective independent-particle picture. To do so, we revisit in detail the notion of ESPEs in the context of strongly correlated many-nucleon systems and illustrate the necessity to extract ESPEs through the diagonalization of the centroid {\\it matrix}, as originally argued by Baranger. For the purpose of illustration, we analyse the impact of correlations on observable one-nucleon separation energies and non-observable ESPEs in selected closed-shell oxygen and calcium isotopes. We then state and illustrate the non-observability of ESPEs. Similarly to spectroscopic factors, ESPEs can indeed be modified by a redefinition of inaccessible quantities while leaving actual observables unchanged. This leads to the absolute necessity to employ consistent structure and reaction models based on the same nuclear Hamiltonian to extract the shell structure in a meaningful fashion from experimental data.

  17. Particle-vibration coupling effect on the $\\beta$-decay of magic nuclei

    E-Print Network [OSTI]

    Niu, Yifei; Colo, Gianluca; Vigezzi, Enrico

    2015-01-01T23:59:59.000Z

    Nuclear $\\beta$-decay in magic nuclei is investigated, taking into account the coupling between particle and collective vibrations,on top of self-consistent random phase approximation calculations based on Skyrme density functionals. The low-lying Gamow-Teller strength is shifted downwards and at times becomes fragmented; as a consequence, the $\\beta$-decay half-lives are reduced due to the increase of the phase space available for the decay. In some cases, this leads to a very good agreement between theoretical and experimental lifetimes: this happens, in particular, in the case of the Skyrme force SkM*, that can also reproduce the line shape of the high energy Gamow-Teller resonance as it was previously shown.

  18. Optical Model Potential Parameters for p, d, {sup 3}He and Alpha-Particle Scattering on Lithium Nuclei

    SciTech Connect (OSTI)

    Burtebayev, N.; Nassurlla, Marzhan; Nassurlla, Maulen; Kerimkulov, Zh. K. [Institute of Nuclear Physics, Almaty (Kazakhstan); Sakuta, S. B. [Russian Research Center 'Kurchatov Institute', Moscow (Russian Federation)

    2008-11-11T23:59:59.000Z

    Analysis of the p, d, {sup 3}He and {alpha}-particles elastic scattering on the {sup 6}Li and {sup 7}Li nuclei has been done in the framework of the optical model at the beam energies up to 72 MeV. It was shown that the account of the cluster exchange mechanism together with the potential scattering allow reproducing the experimental cross-sections in the whole angular range.

  19. Particle-number fluctuations and neutron-proton pairing effects on proton and neutron radii of even-even N Almost-Equal-To Z nuclei

    SciTech Connect (OSTI)

    Douici, M.; Allal, N. H.; Fellah, M.; Benhamouda, N.; Oudih, M. R. [Laboratoire de Physique Theorique, Faculte de Physique, USTHB BP 32 El-Alia, 16111 Bab-Ezzouar, Alger (Algeria) and Institut des Sciences et Technologie, Centre Universitaire de Khemis Miliana, Route de Theniet-El-Had, 44225 Khemis-Milia (Algeria); Laboratoire de Physique Theorique, Faculte de Physique, USTHB BP 32 El-Alia, 16111 Bab-Ezzouar, Alger (Algeria) and Centre de Recherche Nucleaire d'Alger, COMENA, BP399 Alger-Gare, Alger (Algeria); Laboratoire de Physique Theorique, Faculte de Physique, USTHB BP 32 El-Alia, 16111 Bab-Ezzouar, Alger (Algeria)

    2012-10-20T23:59:59.000Z

    The particle-number fluctuation effect on the root-mean-square (rms) proton and neutron radii of even-even N Almost-Equal-To Z nuclei is studied in the isovector neutron-proton (np) pairing case using an exact particle-number projection method and the Woods-Saxon model.

  20. Particle acceleration and high-frequency (X-ray and $?$-ray) emission in the jets of active galactic nuclei

    E-Print Network [OSTI]

    V. V. Usov; M. V. Smolsky

    1998-10-26T23:59:59.000Z

    It is suggested that the outflowing plasma in the jets of active galactic nuclei (AGNs) is inhomogeneous and consists of separate clouds. These clouds are strongly magnetized and move away from the central engine at relativistic speeds. The clouds interact with an ambient medium which is assumed to be at rest. In the process of this interaction, particles of the ambient medium are accelerated to high energies at the cloud front and flow ahead of the front. It is shown that the radiation of the accelerated particles may be responsible for the X-ray and $\\gamma$-ray emission from AGN jets. TeV $\\gamma$-ray emission is generated in the inner parts of AGN jets where the Lorentz factor of the cloud fronts is $\\Gamma_0\\geq 30$, while GeV $\\gamma$-ray emission emanates from the outer parts of AGN jets where $\\Gamma_0$ is $\\sim 10$.

  1. Interference of fission amplitudes of neutron resonances and T-odd asymmetry for various prescission third particles in the ternary fission of nuclei

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru [Voronezh State University (Russian Federation); Bunakov, V. E. [Russian Academy of Sciences, Petersburg Nuclear Physics Institute (Russian Federation); Kadmensky, S. S. [Voronezh State University (Russian Federation)

    2011-12-15T23:59:59.000Z

    Differential cross sections for reactions of the true ternary fission of nuclei that was induced by cold polarized neutrons were constructed with allowance of the effect that Coriolis interaction and the interference between fission amplitudes of neutron resonances excited in fissile nuclei upon incidentneutron capture by target nuclei exerted on angular distributions of prescission third particles (alpha particles, neutrons, or photons). It is shown that T -odd TRI- and ROT-type asymmetries for prescission alpha particles are associated with, respectively, the odd and even components of the Coriolis interaction-perturbed amplitude of angular distributions of particles belonging to the types indicated above. These asymmetries have angular distributions differing from each other and stemming from a nontrivial dependence of these components on the neutron-resonance spins J{sub s} and their projections K{sub s} onto the symmetry axis of the nucleus involved. It is shown that angular distributions of prescission photons and neutrons from reactions of the ternary fission of nuclei that is induced by cold polarized neutrons are determined by the effect of Coriolis forces exclusively. Therefore, the emerging T-odd asymmetries have a character of a ROT-type asymmetry and are universal for all target nuclei.

  2. Light Charged Particle Emission Following the Fusion of 18O Ions with 12C Nuclei at Energies Near and Below the

    E-Print Network [OSTI]

    de Souza, Romualdo T.

    Light Charged Particle Emission Following the Fusion of 18O Ions with 12C Nuclei at Energies Near Releases more energy in a few hours than our sun does in a decade X-ray superbursts thought to be fueled by 12C+12C fusion in the outer crust Temperature of the outer crust is too low (~3×106 K) relative

  3. Proof of Concept: Cloud Condensation Nucleus Counter

    E-Print Network [OSTI]

    Delene, David J.

    North Dakota project. The solid circle is the mean value, the horizontal line is the 50th percentile Price High Price #12;Research Applications · One commercially available cloud condensation nuclei (CCN) counter. · Available since 2002 · Sold over 100 Units, Mostly Labs · Price is Approximately $70

  4. Distributed performance counters

    DOE Patents [OSTI]

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26T23:59:59.000Z

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  5. A microscopic particle-vibration coupling approach for atomic nuclei. Giant resonance properties and the renormalization of the effective interaction

    E-Print Network [OSTI]

    Marco Brenna

    2014-08-01T23:59:59.000Z

    The self-consistent mean-field (SCMF) theory describes many properties of the ground state and excited states of the atomic nucleus, such as masses, radii, deformations and giant resonance energies. SCMF models are based on the independent particle picture where nucleons are assumed to move in a self-generated average potential. In the first part of this work, we apply a state-of-the-art SCMF approach, based on the Skyrme effective interaction, to two different excitations (viz. the pygmy dipole resonance and the isovector giant quadrupole resonance), investigating their relation with the nuclear matter symmetry energy, which corresponds to the energy cost for changing protons into neutrons and is a key parameter for the nuclear equation of state. However, SCMF models present well known limitations which require the inclusion of further dynamical correlations, e.g. the ones coming from the interweaving between single-particle and collective degrees of freedom (particle-vibration coupling - PVC). In the second part of this work, we report on the application to inclusive (namely, the strength function of giant resonances) and exclusive (the gamma decay of giant resonances) observables of a new self-consistent model based on the PVC idea in the Skyrme framework. In our model we use an effective interaction fitted at mean-field level to some selected experimental data. In principle, when these interactions are used in beyond mean-field theories, one would need to re-determine the parameters of the interaction at the same level of approximation. Moreover, due to the zero-range nature of the employed interaction, divergences arise. In the last and most innovative part of this thesis, we develop, for the first time in finite nuclei, a possible way to cure the divergences, paving the way to the possibility of producing an effective interaction fitted at PVC level.

  6. Development of a Mobile Ice Nucleus Counter

    SciTech Connect (OSTI)

    Kok, Gregory; Kulkarni, Gourihar

    2014-07-10T23:59:59.000Z

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70 deg C, and a single stage system can operate the warm wall at -45 deg C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  7. Channel coupling and exchange of an alpha-particle cluster in deuteron scattering on {sup 6}Li nuclei

    SciTech Connect (OSTI)

    Sakuta, S. B., E-mail: sakuta@dni.polyn.kiae.su [Russian Research Centre Kurchatov Institute (Russian Federation); Burtebaev, N. [National Nuclear Center of the Republic Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Artemov, S. V.; Yarmukhamedov, R. [National Nuclear Center of the Republic Uzbekistan, Institute of Nuclear Physics (Uzbekistan)

    2012-07-15T23:59:59.000Z

    Existing experimental data on elastic and inelastic deuteron scattering on {sup 6}Li nuclei in the energy range from 8 to 50 MeV were analyzed within the approach of coupled reaction channels. The coupling of elastic scattering and inelastic scattering accompanied by the transition to the 3{sup +} state at E{sub x} 2.186 MeV and the mechanism involving the exchange of an alpha-particle cluster were taken into account in respective calculations. The phenomenological potentials obtained from the present analysis describe well experimental angular distributions at all energies and in full angular ranges. The depths of the real and imaginary parts of the potentials in question depend smoothly on energy at fixed values of the remaining parameters. The energy dependence of relevant volume integrals agrees well with similar data for the p + {sup 6}Li, {alpha} + {sup 6}Li, and {sup 12}C + {sup 12}C systems and with the predictions of a microscopic theory.

  8. Compressor surge counter

    DOE Patents [OSTI]

    Castleberry, Kimberly N. (Harriman, TN)

    1983-01-01T23:59:59.000Z

    A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered non-responsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.

  9. Systematic trends in beta-delayed particle emitting nuclei: The case of beta-p-alpha emission from 21Mg

    E-Print Network [OSTI]

    M. V. Lund; M. J. G. Borge; J. A. Briz; J. Cederkäll; H. O. U. Fynbo; J. H. Jensen; B. Jonson; K. L. Laursen; T. Nilsson; A. Perea; V. Pesudo; K. Riisager; O. Tengblad

    2015-06-12T23:59:59.000Z

    We have observed beta+-delayed alpha and p-alpha emission from the proton-rich nucleus 21Mg produced at the ISOLDE facility at CERN. The assignments were cross-checked with a time distribution analysis. This is the third identified case of beta-p-alpha emission. We discuss the systematic of beta-delayed particle emission decays, show that our observed decays fit naturally into the existing pattern, and argue that the patterns are to a large extent caused by odd-even effects.

  10. Acne treatments (over-the-counter) Acupuncture

    E-Print Network [OSTI]

    Bordenstein, Seth

    -the- counter) Corneal keratotomy Cough drops & sore throat lozenges (over-the-counter) Cough syrup (over & flu prevention Over-the-counter cough drops & sore throat lozenges Over-the-counter cough syrup Over

  11. Neutron counter based on beryllium activation

    SciTech Connect (OSTI)

    Bienkowska, B.; Prokopowicz, R.; Kaczmarczyk, J.; Paducha, M. [Institute of Plasma Physics and Laser Microfusion (IPPLM), Hery 23, 01-497 Warsaw (Poland); Scholz, M.; Igielski, A. [Institute of Nuclear Physics PAS (IFJPAN), Radzikowskiego 152, 31-342 Krakow (Poland); Karpinski, L. [Faculty of Electrical Engineering, Rzeszow University of Technology, Pola 2, 35-959 Rzeszow (Poland); Pytel, K. [National Centre for Nuclear Research (NCBJ), Soltana 7, 05-400 Otwock - Swierk (Poland)

    2014-08-21T23:59:59.000Z

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction {sup 9}Be(n, ?){sup 6}He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, {sup 6}He, decays with half-life T{sub 1/2} = 0.807 s emitting ?{sup ?} particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of ?–particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known ?–source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5–the Monte Carlo transport code. It allowed proper application of the results of transport calculations of ?{sup ?} particles emitted from radioactive {sup 6}He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  12. Monte Carlo Simulations of Grid Walled Proportional Counters with Different Site Sizes for HZE Radiation

    E-Print Network [OSTI]

    Liu, Haifeng

    2012-07-16T23:59:59.000Z

    Tissue-equivalent proportional counters are frequently used to measure dose and dose equivalent in cosmic radiation fields that include high-Z, high-energy (HZE) particles. The fact that particles with different stopping powers can produce the same...

  13. Space and power efficient hybrid counters array

    DOE Patents [OSTI]

    Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

    2010-03-30T23:59:59.000Z

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  14. Space and power efficient hybrid counters array

    DOE Patents [OSTI]

    Gara, Alan G. (Mount Kisco, NY); Salapura, Valentina (Chappaqua, NY)

    2009-05-12T23:59:59.000Z

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  15. The development of a planar multiwire proportional counter

    E-Print Network [OSTI]

    Hensley, John Richard

    1970-01-01T23:59:59.000Z

    140 THEORY 1. Proportional Counter Theory A proportional counter operates on the principle of using the ionization produced in a gas by a charged particle passing through it (or an x-ray stopping in it) to create an avalanche of secondari- ly... distance approximately equal to the beam width in figures 15 and 16, where x-rays were used. In figure 17, where alpha particles ivere completely stopping in the detector gas, the fall-off in efficiency occurs over a distance much greater than the 0. 82...

  16. A scintillation counter for nuclear research

    E-Print Network [OSTI]

    Trail, Carroll Clark

    1951-01-01T23:59:59.000Z

    AND ALPHA DETECTION GAMMA DETECTION Photoelectric Absorption Compton EXf'ect Pair Formation DESCRIPTION OF EQUIPMENT DETECTION Phosphors Photomultiplier Tube Photomultiplier Power Supply AMPLIFICATION AND PULSE SELECTION Preamplifier Main Amplif... schemes of radioactive nuclei. INTRODiJCT ION Scintillation counting in princ1ple is nothing new. RuDisrford, about the turn of the century counted alpha particles by scintillation means, but counting flashes by the eye was slow and tedious...

  17. Interactions of Relativistic $^6$Li Nuclei with Photoemulsion Nuclei

    E-Print Network [OSTI]

    Adamovich, M I; Larionova, V G; Peresadko, N G; Kharlamov, S P; Bogdanov, V G; Plyushchev, V A; Solovyeva, Z I; 10.1063/S6208-1378(99)007788

    2011-01-01T23:59:59.000Z

    Inelastic interactions of nuclei accelerated to a momentum of 4.5 GeV/$c$ per projectile nucleon with photoemulsion nuclei have been investigated. The main features of these interactions - mean ranges of $^6$Li nuclei, mean multiplicities of secondaries, the isotopic composition of fragments, fragmentation channels, and the mean transverse momenta of projectile fragments - have been measured. The probability of the charge-exchange reaction featuring lithium nuclei has been determined. The results obtained for the $^6$Li nucleus have been compared with data for other nuclei. The observed features of $^6$Li interactions with other nuclei indicate that the $^6$Li structure in the form of the loosely bound system consisting of an $\\alpha$-particle and a deuteron cluster clearly manifests itself in these interactions. Events resulting in the coherent dissociation of $^6$Li nuclei into $^4$He+$d$, $^3$He+$t$, and $t+d+p$ and involving low-lying excitations of $^6$Li have been observed.

  18. Interactions of Relativistic $^6$Li Nuclei with Photoemulsion Nuclei

    E-Print Network [OSTI]

    M. I. Adamovich; I. A. Konorov; V. G. Larionova; N. G. Peresadko; S. P. Kharlamov; V. G. Bogdanov; V. A. Plyushchev; Z. I. Solovyeva

    2011-09-29T23:59:59.000Z

    Inelastic interactions of nuclei accelerated to a momentum of 4.5 GeV/$c$ per projectile nucleon with photoemulsion nuclei have been investigated. The main features of these interactions - mean ranges of $^6$Li nuclei, mean multiplicities of secondaries, the isotopic composition of fragments, fragmentation channels, and the mean transverse momenta of projectile fragments - have been measured. The probability of the charge-exchange reaction featuring lithium nuclei has been determined. The results obtained for the $^6$Li nucleus have been compared with data for other nuclei. The observed features of $^6$Li interactions with other nuclei indicate that the $^6$Li structure in the form of the loosely bound system consisting of an $\\alpha$-particle and a deuteron cluster clearly manifests itself in these interactions. Events resulting in the coherent dissociation of $^6$Li nuclei into $^4$He+$d$, $^3$He+$t$, and $t+d+p$ and involving low-lying excitations of $^6$Li have been observed.

  19. Alternatives for Helium-3 in Multiplicity Counters

    SciTech Connect (OSTI)

    Ely, James H.; Siciliano, Edward R.; Lintereur, Azaree T.; Swinhoe, Martyn T.

    2013-04-01T23:59:59.000Z

    Alternatives to helium-3 are being actively pursued due to the shortage and rising costs of helium-3. For safeguards applications, there are a number of ongoing investigations to find alternatives that provide the same capability in a cost-effective manner. One of the greatest challenges is to find a comparable alternative for multiplicity counters, since they require high efficiency and short collection or die-away times. Work has been progressing on investigating three commercially available alternatives for high efficiency multiplicity counters: boron trifluoride (BF3) filled proportional tubes, boron-lined proportional tubes, and lithium fluoride with zinc sulfide coated light guides. The baseline multiplicity counter used for the investigation is the Epithermal Neutron Multiplicity Counter with 121 helium-3 filled tubes at 10 atmosphere pressure, which is a significant capability to match. The primary tool for the investigation has been modeling and simulation using the Monte Carlo N-Particle eXtended (MCNPX) radiation transport program, with experiments to validate the models. To directly calculate the coincidence rates in boron-lined (and possibly other) detectors, the MCNPX code has been enhanced to allow the existing coincidence tally to be used with energy deposition rather than neutron capture reactions. This allows boron-lined detectors to be modeled more accurately. Variations of tube number and diameter along with variations in the amount of inter-tube moderator have been conducted for the BF3 and boron-lined cases. Tube pressure was investigated for BF3, up to two atmospheres, as well as optimal boron thickness in the boron-lined tubes. The lithium fluoride was modeled as sheets of material with light guides in between, and the number and thickness of the sheets investigated. The amount of light guide, which in this case doubles as a moderator, was also optimized. The results of these modeling and simulation optimization investigations are described and results presented.

  20. Cloud Condensation Nuclei (CCN) Analysis of Biogenic Secondary Organic Aerosol

    E-Print Network [OSTI]

    Collins, Gary S.

    Cloud Condensation Nuclei (CCN) Analysis of Biogenic Secondary Organic Aerosol Rachel L. Atlas1' gas-phase emissions and the aerosols they form (figure 6), including a cloud condensation nuclei Cloud condensation nuclei (CCN) are particles which water vapor condenses onto to form cloud droplets

  1. The Assembly of the Belle II TOP Counter

    E-Print Network [OSTI]

    Boqun Wang; for the Belle II PID Group

    2015-01-13T23:59:59.000Z

    A new type of ring-imaging Cherenkov counter, called TOP counter, has been developed for particle identification at the Belle II experiment to run at the SuperKEKB accelerator in KEK, Japan. The detector consists of 16 identical modules arranged azimuthally around the beam line. The assembly procedure for a TOP module is described. This procedure includes acceptance testing of the quartz mirror, prism, and quartz bar radiators. The acceptance tests include a chip search and measurements of bulk transmittance and total internal reflectance. The process for aligning and gluing the optical components together is described.

  2. Monte Carlo simulations of solid walled proportional counters with different site size for HZE radiation 

    E-Print Network [OSTI]

    Wang, Xudong

    2009-05-15T23:59:59.000Z

    Characterizing high z high energy (HZE) particles in cosmic radiation is of importance for the study of the equivalent dose to astronauts. Low pressure, tissue equivalent proportional counters (TEPC) are routinely used to evaluate radiation...

  3. Monte Carlo simulations of solid walled proportional counters with different site size for HZE radiation

    E-Print Network [OSTI]

    Wang, Xudong

    2009-05-15T23:59:59.000Z

    Characterizing high z high energy (HZE) particles in cosmic radiation is of importance for the study of the equivalent dose to astronauts. Low pressure, tissue equivalent proportional counters (TEPC) are routinely used to evaluate radiation...

  4. Understanding nuclei in the upper sd - shell

    SciTech Connect (OSTI)

    Sarkar, M. Saha; Bisoi, Abhijit; Ray, Sudatta [Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Kshetri, Ritesh [Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India and Sidho-Kanho-Birsha University, Purulia - 723101 (India); Sarkar, S. [Indian Institute of Engineering Science and Technology, Shibpur, Howrah - 711103 (India)

    2014-08-14T23:59:59.000Z

    Nuclei in the upper-sd shell usually exhibit characteristics of spherical single particle excitations. In the recent years, employment of sophisticated techniques of gamma spectroscopy has led to observation of high spin states of several nuclei near A ? 40. In a few of them multiparticle, multihole rotational states coexist with states of single particle nature. We have studied a few nuclei in this mass region experimentally, using various campaigns of the Indian National Gamma Array setup. We have compared and combined our empirical observations with the large-scale shell model results to interpret the structure of these nuclei. Indication of population of states of large deformation has been found in our data. This gives us an opportunity to investigate the interplay of single particle and collective degrees of freedom in this mass region.

  5. Aerogel Cerenkov Counter for the BELLE Experiment

    E-Print Network [OSTI]

    Iijima Adachi; Belle Preprint

    In the BELLE experiment at KEKB, a threshold Cerenkov counter system based on silica aerogels will be used to provide a ß=K separation in the momentum region from 0.8 to 3.5 GeV/c. The detector design, recent progresses in R&D's and results of beam tests are reviewed in this talk. 1 Introduction Particle identification, in particular the identification of charged pions and kaons, plays an important role for the studies of CP -violation in B-factory experiments. In the BELLE experiment at KEKB, a threshold aerogel Cerenkov counter (ACC) will be used to extend the momentum region beyond the reach of dE=dx and time-of-flight (TOF) measurements [1]. This paper gives a brief description of the detector design, recent progresses in R&D's and results of beam tests. 2 Detector design Figure 1 shows the design of the BELLE ACC system, which consists of a barrel ACC and a forward endcap ACC. The barrel ACC is a 900-element array, segmented into 15 and 60 in z and OE directions, respectivel...

  6. Basic Research Needs for Countering Terrorism

    SciTech Connect (OSTI)

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01T23:59:59.000Z

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  7. Apparatuses and methods for detecting, identifying and quantitating radioactive nuclei and methods of distinguishing neutron stimulation of a radiation particle detector from gamma-ray stimulation of a detector

    DOE Patents [OSTI]

    Cole, Jerald D. (Idaho Falls, ID); Drigert, Mark W. (Idaho Falls, ID); Reber, Edward L. (Idaho Falls, ID); Aryaeinejad, Rahmat (Idaho Falls, ID)

    2001-01-01T23:59:59.000Z

    In one aspect, the invention encompasses a method of detecting radioactive decay, comprising: a) providing a sample comprising a radioactive material, the radioactive material generating decay particles; b)providing a plurality of detectors proximate the sample, the detectors comprising a first set and a second set, the first set of the detectors comprising liquid state detectors utilizing liquid scintillation material coupled with photo tubes to generate a first electrical signal in response to decay particles stimulating the liquid scintillation material, the second set of the detectors comprising solid state detectors utilizing a crystalline solid to generate a second electrical signal in response to decay particles stimulating the crystalline solid; c) stimulating at least one of the detectors to generate at least one of the first and second electrical signals, the at least one of the first and second electrical signals being indicative of radioactive decay in the sample. In another aspect, the invention encompasses an apparatus for identifying and quantitating radioactive nuclei of a sample comprising radioactive material that decays to generate neutrons and high-energy .gamma.-rays.

  8. Single particle characterization, source apportionment, and aging effects of ambient aerosols in Southern California

    E-Print Network [OSTI]

    Shields, Laura Grace

    2008-01-01T23:59:59.000Z

    detection efficiencies of aerosol time of flight masscomposition of ambient aerosol particles. Environmentalsize dependent response of aerosol counters, Atmospheric

  9. Boron-10 Lined Proportional Counter Wall Effects

    SciTech Connect (OSTI)

    Siciliano, Edward R.; Kouzes, Richard T.

    2012-05-01T23:59:59.000Z

    The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube based system in the configuration of a coincidence counter. This report provides information about how variations in proportional counter radius and gas pressure in a typical coincident counter design might affect the observed signal from boron-lined tubes. A discussion comparing tubes to parallel plate counters is also included.

  10. NACRE II: an update of the NACRE compilation of charged-particle-induced thermonuclear reaction rates for nuclei with mass number $A < 16$

    E-Print Network [OSTI]

    Yi Xu; Kohji Takahashi; Stephane Goriely; Marcel Arnould; Masahisa Ohta; Hiroaki Utsunomiya

    2013-10-26T23:59:59.000Z

    An update of the NACRE compilation [Angulo et al., Nucl. Phys. A 656 (1999) 3] is presented. This new compilation, referred to as NACRE II, reports thermonuclear reaction rates for 34 charged-particle induced, two-body exoergic reactions on nuclides with mass number $A<16$, of which fifteen are particle-transfer reactions and the rest radiative capture reactions. When compared with NACRE, NACRE II features in particular (1) the addition to the experimental data collected in NACRE of those reported later, preferentially in the major journals of the field by early 2013, and (2) the adoption of potential models as the primary tool for extrapolation to very low energies of astrophysical $S$-factors, with a systematic evaluation of uncertainties. As in NACRE, the rates are presented in tabular form for temperatures in the $10^{6}$ $\\simeq\\leq$ T $\\leq$ $10^{10}$ K range. Along with the 'adopted' rates, their low and high limits are provided. The new rates are available in electronic form as part of the Brussels Library (BRUSLIB) of nuclear data. The NACRE II rates also supersede the previous NACRE rates in the Nuclear Network Generator (NETGEN) for astrophysics. [http://www.astro.ulb.ac.be/databases.html.

  11. Orbital and spin scissors modes in superfluid nuclei

    E-Print Network [OSTI]

    Balbutsev, E B; Schuck, P

    2015-01-01T23:59:59.000Z

    Nuclear scissors modes are considered in the frame of Wigner function moments method generalized to take into account spin degrees of freedom and pair correlations simultaneously. A new source of nuclear magnetism, connected with counter-rotation of spins up and down around the symmetry axis (hidden angular momenta), is discovered. Its inclusion into the theory allows one to improve substantially the agreement with experimental data in the description of energies and transition probabilities of scissors modes in rare earth nuclei.

  12. Orbital and spin scissors modes in superfluid nuclei

    E-Print Network [OSTI]

    E. B. Balbutsev; I. V. Molodtsova; P. Schuck

    2015-02-19T23:59:59.000Z

    Nuclear scissors modes are considered in the frame of Wigner function moments method generalized to take into account spin degrees of freedom and pair correlations simultaneously. A new source of nuclear magnetism, connected with counter-rotation of spins up and down around the symmetry axis (hidden angular momenta), is discovered. Its inclusion into the theory allows one to improve substantially the agreement with experimental data in the description of energies and transition probabilities of scissors modes in rare earth nuclei.

  13. High Speed Architecture for Galois/Counter Mode of Operation (GCM)

    E-Print Network [OSTI]

    Counter with CBC-MAC (CCM) [14], EAX [15], Carter Wegman with Counter (CWC) [17], and Galois Counter Mode

  14. Organizational Structure of COUNTER September 2014

    E-Print Network [OSTI]

    Napp, Nils

    of COUNTER to an Executive Committee, chaired by David Sommer, of David Sommer Consulting. Day Sommer David Sommer Consulting, UK Harald Wirsching Springer Science+Business Media, Germany Company Secretary: Peter Shepherd, COUNTER Executive Committee David Sommer David Sommer Consulting, UK (Chair

  15. : : ". RSST I Lunar Day Counter Reliability Analysis

    E-Print Network [OSTI]

    Rathbun, Julie A.

    : : ". RSST I Lunar Day Counter Reliability Analysis NO. ATM 846 PAGE 1 REV. MO. OF 10 DATE 12/3/69 This ATM presents a Reliability analysis of the Lunar Day Counter, the Resettable Solid State Timer (RSST equipment. The analysis is based on a parts count, average failure rates and two (2) years operation

  16. Aerosol measurements at a high-elevation site: composition, size, and cloud condensation nuclei activity

    E-Print Network [OSTI]

    Friedman, B.

    Measurements of cloud condensation nuclei (CCN) concentrations, single particle composition and size distributions at a high-elevation research site from March 2011 are presented.

  17. Cirrus cloud formation and the role of heterogeneous ice nuclei

    E-Print Network [OSTI]

    Froyd, Karl D.

    2013-01-01T23:59:59.000Z

    Composition, size, and phase are key properties that define the ability of an aerosol particle to initiate ice in cirrus clouds. Properties of cirrus ice nuclei (IN) have not been well constrained due to a lack of systematic ...

  18. Counter-ions at single charged wall: Sum rules

    E-Print Network [OSTI]

    Ladislav Samaj

    2013-04-15T23:59:59.000Z

    For inhomogeneous classical Coulomb fluids in thermal equilibrium, like the jellium or the two-component Coulomb gas, there exists a variety of exact sum rules which relate the particle one-body and two-body densities. The necessary condition for these sum rules is that the Coulomb fluid possesses good screening properties, i.e. the particle correlation functions or the averaged charge inhomogeneity, say close to a wall, exhibit a short-range (usually exponential) decay. In this work, we study equilibrium statistical mechanics of an electric double layer with counter-ions only, i.e. a globally neutral system of equally charged point-like particles in the vicinity of a plain hard wall carrying a fixed uniform surface charge density of opposite sign. At large distances from the wall, the one-body and two-body counter-ion densities go to zero slowly according to the inverse-power law. In spite of the absence of screening, all known sum rules are shown to hold for two exactly solvable cases of the present system: in the weak-coupling Poisson-Boltzmann limit (in any spatial dimension larger than one) and at a special free-fermion coupling constant in two dimensions. This fact indicates an extended validity of the sum rules and provides a consistency check for reasonable theoretical approaches.

  19. acid cycle counters: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Design to Counter Electromagnetic Interrogation of Targets Mathematics Websites Summary: Stealth Design to Counter Electromagnetic Interrogation of Targets H.T. Banks, K. Ito,...

  20. acorde scintillator counters: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Design to Counter Electromagnetic Interrogation of Targets Mathematics Websites Summary: Stealth Design to Counter Electromagnetic Interrogation of Targets H.T. Banks, K. Ito,...

  1. The neutron long counter NERO for studies of beta-delayed neutron emission in the r-process

    E-Print Network [OSTI]

    Pereira, J; Lorusso, G; Santi, P; Couture, A; Daly, J; Del Santo, M; Elliot, T; Goerres, J; Herlitzius, C; Kratz, K -L; Lamm, L O; Lee, H Y; Montes, F; Ouellette, M; Pellegrini, E; Reeder, P; Schatz, H; Schertz, F; Schnorrenberger, L; Smith, K; Stech, E; Strandberg, E; Ugalde, C; Wiescher, M; Woehr, A; 10.1016/j.nima.2010.02.262

    2010-01-01T23:59:59.000Z

    The neutron long counter NERO was built at the National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, for measuring beta-delayed neutron-emission probabilities. The detector was designed to work in conjunction with a beta-decay implantation station, so that beta decays and beta-delayed neutrons emitted from implanted nuclei can be measured simultaneously. The high efficiency of about 40%, for the range of energies of interest, along with the small background, are crucial for measuring beta-delayed neutron emission branchings for neutron-rich r-process nuclei produced as low intensity fragmentation beams in in-flight separator facilities.

  2. The neutron long counter NERO for studies of beta-delayed neutron emission in the r-process

    E-Print Network [OSTI]

    J. Pereira; P. Hosmer; G. Lorusso; P. Santi; A. Couture; J. Daly; M. Del Santo; T. Elliot; J. Goerres; C. Herlitzius; K. -L. Kratz; L. O. Lamm; H. Y. Lee; F. Montes; M. Ouellette; E. Pellegrini; P. Reeder; H. Schatz; F. Schertz; L. Schnorrenberger; K. Smith; E. Stech; E. Strandberg; C. Ugalde; M. Wiescher; A. Woehr

    2010-07-28T23:59:59.000Z

    The neutron long counter NERO was built at the National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, for measuring beta-delayed neutron-emission probabilities. The detector was designed to work in conjunction with a beta-decay implantation station, so that beta decays and beta-delayed neutrons emitted from implanted nuclei can be measured simultaneously. The high efficiency of about 40%, for the range of energies of interest, along with the small background, are crucial for measuring beta-delayed neutron emission branchings for neutron-rich r-process nuclei produced as low intensity fragmentation beams in in-flight separator facilities.

  3. Fission Barriers of Compound Superheavy Nuclei

    E-Print Network [OSTI]

    J. C. Pei; W. Nazarewicz; J. A. Sheikh; A. K. Kerman

    2009-02-27T23:59:59.000Z

    The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. In this work, we investigate the isentropic fission barriers by means of the self-consistent nuclear density functional theory. The relationship between isothermal and isentropic descriptions is demonstrated. Calculations have been carried out for $^{264}$Fm, $^{272}$Ds, $^{278}$112, $^{292}$114, and $^{312}$124. For nuclei around $^{278}$112 produced in "cold fusion" reactions, we predict a more rapid decrease of fission barriers with excitation energy as compared to the nuclei around $^{292}$114 synthesized in "hot fusion" experiments. This is explained in terms of the difference between the ground-state and saddle-point temperatures. The effect of the particle gas is found to be negligible in the range of temperatures studied.

  4. New charge radius relations for atomic nuclei

    E-Print Network [OSTI]

    B. H. Sun; Y. Lu; J. P. Peng; C. Y. Liu; Y. M. Zhao

    2014-11-24T23:59:59.000Z

    We show that the charge radii of neighboring atomic nuclei, independent of atomic number and charge, follow remarkably very simple relations, despite the fact that atomic nuclei are complex finite many-body systems governed by the laws of quantum mechanics. These relations can be understood within the picture of independent-particle motion and by assuming neighboring nuclei having similar pattern in the charge density distribution. A root-mean-square (rms) deviation of 0.0078 fm is obtained between the predictions in these relations and the experimental values, i.e., a comparable precision as modern experimental techniques. Such high accuracy relations are very useful to check the consistence of nuclear charge radius surface and moreover to predict unknown nuclear charge radii, while large deviations from experimental data is seen to reveal the appearance of nuclear shape transition or coexsitence.

  5. Aquatic manoeuvering with counter-propagating waves: a novel

    E-Print Network [OSTI]

    Lauder, George V.

    Aquatic manoeuvering with counter-propagating waves: a novel locomotive strategy Oscar M. Curet1 of these inward counter-propagating waves. In addition, we compare the flow structure and upward force generated by inward counter-propagating waves to standing waves, unidirectional waves, and outward counter-propagating

  6. Modular high speed counter employing edge-triggered code

    DOE Patents [OSTI]

    Vanstraelen, G.F.

    1993-06-29T23:59:59.000Z

    A high speed modular counter (100) utilizing a novel counting method in which the first bit changes with the frequency of the driving clock, and changes in the higher order bits are initiated one clock pulse after a 0'' to 1'' transition of the next lower order bit. This allows all carries to be known one clock period in advance of a bit change. The present counter is modular and utilizes two types of standard counter cells. A first counter cell determines the zero bit. The second counter cell determines any other higher order bit. Additional second counter cells are added to the counter to accommodate any count length without affecting speed.

  7. Superdeformation in nuclei

    SciTech Connect (OSTI)

    Khoo, Tenk Lek [Argonne National Laboratory, IL (United States)

    1993-12-31T23:59:59.000Z

    Superdeformation arises because of the occurrence of a secondary minimum (or false vacuum) at large deformation. Thus, superdeformed nuclei provide an opportunity for the study of physics in a false vacuum. Perspectives will be given on three aspects of superdeformed nuclei: (i) the occurrence of identical bands, (ii) the feeding of superdeformed bands; and (iii) their decay. Some aspects of superdeformation will be related to other fields of chemistry and physics.

  8. The use of polycarbonate in proportional counters

    SciTech Connect (OSTI)

    Trow, M.; Smith, A. (Mullard Space Science Laboratory, Department of Physics and Astronomy, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom))

    1992-01-01T23:59:59.000Z

    Proportional counters are relatively sensitive to contamination through outgassing and the range of electrical insulators suitable for use in their manufacture is quite limited. Although small amounts of plastics such as polychlorotrifluoroethylene have been used as feedthroughs, ceramics are most commonly used when sealed counters with long lives are required. Ceramics have poor and widely scattered mechanical properties and the use of a more robust material is often highly desirable. Of particular interest is the use of polymers and this work examines polycarbonate in particular. To investigate its suitability in terms of outgassing a simple cylindrical, single anode proportional counter containing a large sample of polycarbonate was baked at {similar to}100 {degree}C and filled with a CO{sub 2}/Ar/Xe mixture (5:47.5:47.5 by pressure, respectively). Subsequent measurements of the counter indicated an increase in gain, which, after a second similar filling, was identified to be associated with a preferential loss of CO{sub 2} to the polycarbonate. The consequences of this result and the circumstances under which polycarbonate could be used on a large scale in the construction of proportional counters are discussed.

  9. EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH European Laboratory for Particle Physics

    E-Print Network [OSTI]

    Boyer, Edmond

    EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH European Laboratory for Particle Physics Internal Note performance of the counter for the detection of one MIP 3 #12;(Minimum Ionizing Particle). Their hardness

  10. Saharan dust particles nucleate droplets in eastern Atlantic clouds Cynthia H. Twohy,1

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    as CCN. Given the dual nature of Saharan dust particles as CCN and ice nuclei, this infusion of dust

  11. Electromagnetically Induced Guiding and Superradiant Amplification of Counter-Propagating Lasers in Plasma

    SciTech Connect (OSTI)

    Fisch, N.J.; Shvets, G.

    1998-08-01T23:59:59.000Z

    The interaction of counter-propagating laser pulses in a plasma in considered. When the frequencies of the two lasers are close, nonlinear modification of the refraction index results in the mutual focusing of the two beams. A short (of order the plasma period) laser pulse can be nonlinearly focused by a long counter-propagating beam which extends over the entire guiding length. It is also demonstrated that a short (< 1/ omega (sub p)) laser pulse can be superradiantly amplified by a counter-propagating long low-intensity pump while remaining ultra-short. Particle-in-Cell simulations indicate that pump depletion can be as high as 40%. This implies that the long pump is efficiently compressed in time without frequency chirping and pulse stretching, making the superradiant amplification an interesting alternative to the conventional method of producing ultra-intense pulses by the chirped-pulse amplification.

  12. The AMS-01 Aerogel Threshold Cherenkov counter

    E-Print Network [OSTI]

    D. Barancourt; F. Barao; G. Barbier; G. Barreira; M. Buenerd; G. Castellini; E. Choumilov; J. Favier; N. Fouque; A. Gougas; V. Hermel; R. Kossakowski; G. Laborie; G. Laurenti; S. -C. Lee; F. Mayet; B. Meillon; Y. -T. Oyang; V. Plyaskin; V. Pojidaev; C. Rossin; D. Santos; F. Vezzu; J. P. Vialle

    2000-10-12T23:59:59.000Z

    The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 degrees orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold Cherenkov counter (ATC) to separate antiprotons from electrons and positrons from protons, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and reports on its performances during the flight STS-91.

  13. Skyrme Model Language in the Theory of Nucleons and Nuclei

    E-Print Network [OSTI]

    V. A. Nikolaev; O. G. Tkachev

    2001-09-21T23:59:59.000Z

    In this talk we try to clarify the problems existing on the way of theorist decided to construct nuclear theory on the generalized Skyrme model background. We conclude that to construct such a model of light nuclei one have to construct a hybrid model where one particle degrees of freedom are concentrated around the surface of the nuclei and soliton with non-trivial structure is located at the center region.

  14. Two and three nucleon K- absorption in nuclei

    E-Print Network [OSTI]

    V. K. Magas; E. Oset; A. Ramos

    2010-03-24T23:59:59.000Z

    We analyze the peaks in the (Lambda p) and (Lambda d) invariant mass distributions, observed in recent FINUDA experiments and claimed to be signals of deeply bound kaonic states, and find them to be naturally explained in terms of K- absorption by two or three nucleons leaving the rest of the original nuclei as spectator. For reactions on heavy nuclei, the subsequent interactions of the particles produced in the primary absorption process with the residual nucleus play an important role. Thus at present there is no experimental evidence of deeply bound K- states in nuclei. However some new physics can be extracted from the data of FINUDA experiments.

  15. alpha particle scattering: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    particle condensation. S. Ohkubo; Y. Hirabayashi 2011-02-11 5 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  16. Scattering Of Light Nuclei

    SciTech Connect (OSTI)

    Quaglioni, S; Navratil, P; Roth, R

    2009-12-15T23:59:59.000Z

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.

  17. Countering Poisonous Inputs with Memetic Neuroevolution

    E-Print Network [OSTI]

    Togelius, Julian

    Countering Poisonous Inputs with Memetic Neuroevolution Julian Togelius1 , Tom Schaul1 , J-dimensional and/or ill-chosen state description. Evidently, some controller inputs are "poisonous also ex- plore which types of inputs are poisonous for two different reinforcement learning problems. 1

  18. ///COUNTER : an artistic system for the transmission of cultural energy

    E-Print Network [OSTI]

    Vincent de Paul, Jegan Joyston

    2009-01-01T23:59:59.000Z

    My thesis introduces ///COUNTER as an artistic system for the transmission of cultural energy. The underlying concepts of ///COUNTER are derived directly from my work on energy access as developed through the eWheel and ...

  19. The decay of hot nuclei

    SciTech Connect (OSTI)

    Moretto, L.G.; Wozniak, G.J.

    1988-11-01T23:59:59.000Z

    The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.

  20. Development of large flow-type proportional counters

    E-Print Network [OSTI]

    Torline, Norbert Kevin

    1967-01-01T23:59:59.000Z

    . . )2 13 ~ The minimum efficiency observed in the region of overlap of the proportional counters as a function of the amount of 1'k. Details of the installation of Kovar seal and tungsten wire. . . . . . . . . . . . . . . )8 vii LXST OF TABLES... proportional counters: (i) All counters are of the continuous gas flow-type a- described in the thesis by K. ~&!. Bull. 2 (2) All counters were constructed with brass cathodes and tungsten wire anodes, with bras" end plates and Kovar seal anode leads...

  1. Electromagnetically Induced Guiding of Counter-Propagating Lasers in Plasmas

    E-Print Network [OSTI]

    - propagating laser pulses and (ii) guiding of an ultra-short tightly focused laser pulse by a counterElectromagnetically Induced Guiding of Counter-Propagating Lasers in Plasmas G. Shvets Princeton for Quantenoptik, D-85748 Garching, Germany Abstract The interaction of counter-propagating laser pulses

  2. Modeling level structures of odd-odd deformed nuclei

    SciTech Connect (OSTI)

    Hoff, R.W.; Kern, J.; Piepenbring, R.; Boisson, J.P.

    1984-09-07T23:59:59.000Z

    A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed. 18 refs., 5 figs., 4 tabs.

  3. Hardware support for software controlled fast multiplexing of performance counters

    DOE Patents [OSTI]

    Salapura, Valentina; Wisniewski, Robert W

    2013-10-01T23:59:59.000Z

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  4. Pairing forces in nuclei

    SciTech Connect (OSTI)

    Chasman, R.R. [Argonne National Lab., IL (United States). Physics Div.

    1996-12-31T23:59:59.000Z

    In this contribution, the author mentions some features of pairing forces that are unique to nuclei and cover some areas of major interest in nuclear structure research, that involve pairing. At the level of most nuclear structure studies, nuclei are treated as consisting of two kinds of fermions (protons and neutrons) in a valence space with rather few levels. These features give rise to unique aspects of pairing forces in nuclei: (1) n-p pairing in T = 0 as well as the usual T = 1 pairing that is characteristic of like fermions; (2) a need to correct pairing calculations for the (1/N) effects that can typically be neglected in superconducting solids. An issue of current concern is the nature of the pairing interaction: several recent studies suggest a need for a density dependent form of the pairing interaction. There is a good deal of feedback between the questions of accurate calculations of pairing interactions and the form and magnitude of the pairing interaction. Finally, the authors discuss some many-body wave functions that are a generalization of the BCS wave function form, and apply them to a calculation of energy level spacings in superdeformed rotational bands.

  5. Dynamic Chirality in Nuclei

    SciTech Connect (OSTI)

    Tonev, D. [Institute for Nuclear Research and Nuclear Energy, BAS, 1784 Sofia (Bulgaria); INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Angelis, G. de [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Brant, S. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Petkov, P. [Institute for Nuclear Research and Nuclear Energy, BAS, 1784 Sofia (Bulgaria); Ventura, A. [ENEA, 40129 Bologna and INFN, Sezione di Bologna (Italy)

    2009-08-26T23:59:59.000Z

    The possible chiral interpretation of twin bands in odd-odd nuclei was investigated in the Interacting Boson Fermion-Fermion Model. The analysis of the wave functions has shown that the possibility for angular momenta of the valence proton, neutron and core to find themselves in the favorable, almost orthogonal geometry is present, but not dominant. Such behaviour is found to be similar in nuclei where both the level energies and the electromagnetic decay properties display the chiral pattern, as well as in those where only the energies of the corresponding levels in the twin bands are close together. The difference in the structure of the two types of chiral candidates nuclei can be attributed to different beta and gamma fluctuations, induced by the exchange boson-fermion interaction of the Interacting Boson Fermion-Fermion Model. In both cases the chirality is weak and dynamic. The existence of doublets of bands in {sup 134}Pr can be attributed to dynamic chirality dominated by shape fluctuations.

  6. Advantages and Limitations of the RICH Technique for Particle Identification

    SciTech Connect (OSTI)

    Ratcliff, Blair N.; /SLAC

    2011-11-07T23:59:59.000Z

    The ring imaging Cherenkov (RICH) technique for hadronic particle identification (PID) is described. The advantages and limitations of RICH PID counters are compared with those of other classic PID techniques, such as threshold Cherenkov counters, ionization loss (dE/dx) in tracking devices, and time of flight (TOF) detectors.

  7. Shared address collectives using counter mechanisms

    DOE Patents [OSTI]

    Blocksome, Michael; Dozsa, Gabor; Gooding, Thomas M; Heidelberger, Philip; Kumar, Sameer; Mamidala, Amith R; Miller, Douglas

    2014-02-18T23:59:59.000Z

    A shared address space on a compute node stores data received from a network and data to transmit to the network. The shared address space includes an application buffer that can be directly operated upon by a plurality of processes, for instance, running on different cores on the compute node. A shared counter is used for one or more of signaling arrival of the data across the plurality of processes running on the compute node, signaling completion of an operation performed by one or more of the plurality of processes, obtaining reservation slots by one or more of the plurality of processes, or combinations thereof.

  8. Self-regulating neutron coincidence counter

    DOE Patents [OSTI]

    Baron, N.

    1980-06-16T23:59:59.000Z

    A device for accurately measuring the mass of /sup 240/Pu and /sup 239/Pu in a sample having arbitrary moderation and mixed with various contaminants. The device utilizes a thermal neutron well counter which has two concentric rings of neutron detectors separated by a moderating material surrounding the well. Neutron spectroscopic information derived by the two rings of detectors is used to measure the quantity of /sup 239/Pu and /sup 240/Pu in device which corrects for background radiation, deadtime losses of the detector and electronics and various other constants of the system.

  9. Antiproton Absorption in Nuclei

    E-Print Network [OSTI]

    Yu. T. Kiselev; E. Ya. Paryev

    2006-01-24T23:59:59.000Z

    We present the analysis of experimental data on forward antiproton production on nuclei. The calculations are done in the framework of a folding model which takes properly into account both incoherent direct proton-nucleon and cascade pion-nucleon antiproton production processes as well as internal nucleon momentum distribution. The effective antiproton-nucleon cross section in nuclear matter and the imaginary part of the antiproton nuclear optical potential are estimated to be 25-45 mb and -(38-56) MeV at normal nuclear matter density, respectively. The results of the performed analysis evidence for the decreasing of antiproton absorption in the nuclear medium.

  10. Hardware support for software controlled fast reconfiguration of performance counters

    DOE Patents [OSTI]

    Salapura, Valentina; Wisniewski, Robert W

    2013-09-24T23:59:59.000Z

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  11. Lineal energy calibration of mini tissue-equivalent gas-proportional counters (TEPC)

    SciTech Connect (OSTI)

    Conte, V.; Moro, D.; Colautti, P. [LNL-INFN, viale dell'Universita 2, I-35020 Legnaro (Italy); Grosswendt, B. [guest at LNL-INFN (Italy)

    2013-07-18T23:59:59.000Z

    Mini TEPCs are cylindrical gas proportional counters of 1 mm or less of sensitive volume diameter. The lineal energy calibration of these tiny counters can be performed with an external gamma-ray source. However, to do that, first a method to get a simple and precise spectral mark has to be found and then the keV/{mu}m value of this mark. A precise method (less than 1% of uncertainty) to identify this markis described here, and the lineal energy value of this mark has been measured for different simulated site sizes by using a {sup 137}Cs gamma source and a cylindrical TEPC equipped with a precision internal {sup 244}Cm alpha-particle source, and filled with propane-based tissue-equivalent gas mixture. Mini TEPCs can be calibrated in terms of lineal energy, by exposing them to {sup 137}Cesium sources, with an overall uncertainty of about 5%.

  12. alpha particle counting: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Francesco Giudice; Ben Gripaios; Rakhi Mahbubani 2011-08-08 5 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  13. alpha particles progress: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  14. alpha particle diagnostics: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    kW, 140 GHz gyrotron tubes used with the Joint Egedal, Jan 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  15. alpha particle preformation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    output intensity of a Raman amplifier and the optimal 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  16. alpha particles: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  17. alpha particles biological effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    streams in interplanetary space. Bo Li; Xing Li 2006-06-07 8 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  18. alpha particles aberraciones: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  19. alpha particle analysis: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  20. alpha particle induced: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    F. L. Roman; V. Avrigeanu; W. von Oertzen 2008-08-05 7 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  1. alpha particles due: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  2. alpha particle transfer: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    their transferring energy to the wave. This could, in turn 2 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  3. alpha particle destabilization: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    their theoretical predictions 1,2, toroidicity-induced 2 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  4. alpha particle orbits: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  5. alpha particle effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    streams in interplanetary space. Bo Li; Xing Li 2006-06-07 8 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  6. alpha particle physics: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    towards an alpha product state. It is shown that single alpha particle orbits in condensates of different nuclei are almost the same. It is thus argued that alpha particle...

  7. alpha particles final: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  8. alpha particle spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    angles. Sergei P. Maydanyuk; Sergei V. Belchikov 2004-12-22 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  9. alpha particle radioimmunotherapy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in tissues (<100 micrometer) (more) Bck, Tom 2011-01-01 2 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  10. alpha particle diagnostic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    kW, 140 GHz gyrotron tubes used with the Joint Egedal, Jan 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  11. alpha particle spectroscopy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  12. P-odd, P-even, and T-odd asymmetries in true quaternary fission of nuclei

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V. [Voronezh State University (Russian Federation)] [Voronezh State University (Russian Federation)

    2013-04-15T23:59:59.000Z

    The coefficients of P-odd, P-even, and T -odd asymmetries for a third and a fourth prescission particle emitted in the true quaternary fission of nuclei that was induced by polarized cold neutrons were studied on the basis of quantum-mechanical fission theory. By using non-evaporation (nonadiabatic) mechanisms of light-particle emission, these coefficients were compared with the analogous coefficients for prescission third particles emitted in the ternary fission of nuclei.

  13. Thermodynamics of pairing transition in hot nuclei

    E-Print Network [OSTI]

    Lang Liu; Zhen-Hua Zhang; Peng-Wei Zhao

    2014-12-16T23:59:59.000Z

    The pairing correlations in hot nuclei $^{162}$Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The heat capacities $C_V$ are evaluated in the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. A S-shaped heat capacity curve, which agrees qualitatively with the experimental data, has been obtained and analyzed in details. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.

  14. Relativistic Hartree-Fock-Bogoliubov model for deformed nuclei

    SciTech Connect (OSTI)

    Ebran, J.-P.; Khan, E.; Pena Arteaga, D. [Institut de Physique Nucleaire, Universite Paris-Sud, IN2P3-CNRS, FR-91406 Orsay Cedex (France); Vretenar, D. [Physics Department, Faculty of Science, University of Zagreb, HR-10000 Zagreb (Croatia)

    2011-06-15T23:59:59.000Z

    The relativistic Hartree-Fock-Bogoliubov model for axially deformed nuclei (RHFBz) is introduced. The model is based on an effective Lagrangian with density-dependent meson-nucleon couplings in the particle-hole channel, and the central part of the Gogny force is used in the pairing channel. The RHFBz quasiparticle equations are solved by expansion in the basis of a deformed harmonic oscillator. Illustrative RHFBz calculations are performed for carbon, neon, and magnesium isotopes. The effect of explicitly including the pion field is investigated for binding energies, deformation parameters, and charge radii and has an impact on the nuclei's shape.

  15. IBA in deformed nuclei

    SciTech Connect (OSTI)

    Casten, R.F.; Warner, D.D.

    1982-01-01T23:59:59.000Z

    The structure and characteristic properties and predictions of the IBA in deformed nuclei are reviewed, and compared with experiment, in particular for /sup 168/Er. Overall, excellent agreement, with a minimum of free parameters (in effect, two, neglecting scale factors on energy differences), was obtained. A particularly surprising, and unavoidable, prediction is that of strong ..beta.. ..-->.. ..gamma.. transitions, a feature characteristically absent in the geometrical model, but manifest empirically. Some discrepancies were also noted, principally for the K=4 excitation, and the detailed magnitudes of some specific B(E2) values. Considerable attention is paid to analyzing the structure of the IBA states and their relation to geometric models. The bandmixing formalism was studied to interpret both the aforementioned discrepancies and the origin of the ..beta.. ..-->.. ..gamma.. transitions. The IBA states, extremely complex in the usual SU(5) basis, are transformed to the SU(3) basis, as is the interaction Hamiltonian. The IBA wave functions appear with much simplified structure in this way as does the structure of the associated B(E2) values. The nature of the symmetry breaking of SU(3) for actual deformed nuclei is seen to be predominantly ..delta..K=0 mixing. A modified, and more consistent, formalism for the IBA-1 is introduced which is simpler, has fewer free parameters (in effect, one, neglecting scale factors on energy differences), is in at least as good agreement with experiment as the earlier formalism, contains a special case of the 0(6) limit which corresponds to that known empirically, and appears to have a close relationship to the IBA-2. The new formalism facilitates the construction of contour plots of various observables (e.g., energy or B(E2) ratios) as functions of N and chi/sub Q/ which allow the parameter-free discussion of qualitative trajectories or systematics.

  16. Evolution of deformations in medium-mass nuclei

    E-Print Network [OSTI]

    H. Sagawa; X. R. Zhou; X. Z. Zhang

    2005-10-28T23:59:59.000Z

    Evolution of quadrupole deformations in $sd$ and $pf$ shell nuclei with mass A= 18$\\sim$56 is studied by using deformed Skyrme Hartree-Fock (HF) model with pairing correlations. We point out that the quadrupole deformations of the nuclei with the isospin T=0 and T=1 show strong mass number dependence as a clear manifestation of dynamical evolution of deformation in nuclear many-body systems. The competition between the deformation driving particle-vibration coupling and the closed shell structure is shown in a systematic study of the ratios between the proton and neutron deformations in nuclei with T=$|$T$_z|$=1. Calculated quadrupole and hexadecapole deformations are compared with shell model results and available experimental data. A relation between the skin thickness and the intrinsic Q$_2$ moments is also discussed.

  17. K- absorption in nuclei by two and three nucleons

    E-Print Network [OSTI]

    V. K. Magas; E. Oset; A. Ramos

    2009-01-08T23:59:59.000Z

    It will be shown that the peaks in the (Lambda p) and (Lambda d) invariant mass distributions, observed in recent FINUDA experiments and claimed to be signals of deeply bound kaonic states, are naturally explained in terms of K- absorption by two or three nucleons leaving the rest of the original nuclei as spectator. For reactions on heavy nuclei, the subsequent interactions of the particles produced in the primary absorption process with the residual nucleus play an important role. Our analyses leads to the conclusion that at present there is no experimental evidence of deeply bound K- state in nuclei. Although the FINUDA experiments have been done for reasons which are not supported a posteriori, some new physics can be extracted from the data.

  18. Counter-Rotating Tandem Motor Drilling System

    SciTech Connect (OSTI)

    Kent Perry

    2009-04-30T23:59:59.000Z

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than that of slim holes. As a result, the research team decided to complete the project, document the tested designs and seek further support for the concept outside of the DOE.

  19. Compton Scattering by Nuclei

    E-Print Network [OSTI]

    M. -Th. Huett; A. I. L'vov; A. I. Milstein; M. Schumacher

    1999-05-13T23:59:59.000Z

    The concept of Compton scattering by even-even nuclei from giant-resonance to nucleon-resonance energies and the status of experimental and theoretical researches in this field are outlined. Nuclear Compton scattering in the giant-resonance energy-region provides information on the dynamical properties of the in-medium mass of the nucleon. The electromagnetic polarizabilities of the nucleon in the nuclear medium can be extracted from nuclear Compton scattering data obtained in the quasi-deuteron energy-region. Recent results are presented for two-body effects due to the mesonic seagull amplitude and due to the excitation of nucleon internal degrees of freedom accompanied by meson exchanges. Due to these studies the in-medium electromagnetic polarizabilities are by now well understood, whereas the understanding of nuclear Compton scattering in the Delta-resonance range is only at the beginning. Phenomenological methods how to include retardation effects in the scattering amplitude are discussed and compared with model predictions.

  20. Gluon density in nuclei

    SciTech Connect (OSTI)

    Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

    1996-10-01T23:59:59.000Z

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

  1. Superconducting magnet for nuclei orientation

    E-Print Network [OSTI]

    Wang, Fa-Chung

    1968-01-01T23:59:59.000Z

    SUPERCOMDUCTING MAGNET FOR NUCLEI ORIENTATION A . Thesis Pa-Chung Wang Submitted. to the Graduate Co11ege of the Texas AEON University in partial fulfillment of the requirements for the degree of NASTEB OP SCIENCE Nay 1968 Nagor Sub...)cot: Physlos SUPEECOKDUCTING MAGNET FOE NUCLEI OBIENTATION A Thesis by Fa-Chung Wang Approved as to style and content byi (Chairman of Committee) Head of Department) Berber i ~ . /' (joe-ber) / f ~;: ( Niay 1968 + & 0 & z c. i ACKNOWLEDGENENTS...

  2. Generalized parton distributions in nuclei

    SciTech Connect (OSTI)

    Vadim Guzey

    2009-12-01T23:59:59.000Z

    Generalized parton distributions (GPDs) of nuclei describe the distribution of quarks and gluons in nuclei probed in hard exclusive reactions, such as e.g. deeply virtual Compton scattering (DVCS). Nuclear GPDs and nuclear DVCS allow us to study new aspects of many traditional nuclear effects (nuclear shadowing, EMC effect, medium modifications of the bound nucleons) as well as to access novel nuclear effects. In my talk, I review recent theoretical progress in the area of nuclear GPDs.

  3. Hardware support for collecting performance counters directly to memory

    DOE Patents [OSTI]

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

    2012-09-25T23:59:59.000Z

    Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

  4. Candidates for Long Lived High-K Ground States in Superheavy Nuclei

    E-Print Network [OSTI]

    Jachimowicz, P; Skalski, J

    2015-01-01T23:59:59.000Z

    On the basis of systematic calculations for 1364 heavy and superheavy nuclei, including odd-systems, we have found a few candidates for high-K ground states in superheavy nuclei. The macroscopic-microscopic model based on the deformed Woods-Saxon single particle potential which we use offers a reasonable description of SH systems, including known: nuclear masses, $Q_{\\alpha}$-values, fission barriers, ground state deformations, super- and hyper-deformed minima in the heaviest nuclei. %For odd and odd-odd systems, both ways of including pairing correlations, % blocking and the quasi-particle method, have been applied. Exceptionally untypical high-K intruder contents of the g.s. found for some nuclei accompanied by a sizable excitation of the parent configuration in daughter suggest a dramatic hindrance of the $\\alpha$-decay. Multidimensional hyper-cube configuration - constrained calculations of the Potential Energy Surfaces (PES's) for one especially promising candidate, $^{272}$ Mt, shows a $\\backsimeq$ 6 Me...

  5. Cluster-model calculations of exotic decays from heavy nuclei

    SciTech Connect (OSTI)

    Buck, B.; Merchant, A.C.

    1989-05-01T23:59:59.000Z

    A cluster model employing a local, effective cluster-core potential is used to investigate exotic decay from heavy nuclei as a quantum tunneling phenomenon within a semiclassical approximation. Excellent agreement with all reported experimental measurements of the decay widths for /sup 14/C and /sup 24/Ne emission is obtained. As an added bonus, the width for alpha particle emission from /sup 212/Po is also calculated in good agreement with experiment.

  6. Multianode cylindrical proportional counter for high count rates

    DOE Patents [OSTI]

    Hanson, J.A.; Kopp, M.K.

    1980-05-23T23:59:59.000Z

    A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (< 60 keV) at count rates of greater than 10/sup 5/ counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

  7. Multianode cylindrical proportional counter for high count rates

    DOE Patents [OSTI]

    Hanson, James A. (Madison, WI); Kopp, Manfred K. (Oak Ridge, TN)

    1981-01-01T23:59:59.000Z

    A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (<60 keV) at count rates of greater than 10.sup.5 counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

  8. Mechanical counter-pressure space suit design using active materials

    E-Print Network [OSTI]

    Holschuh, Bradley Thomas

    2014-01-01T23:59:59.000Z

    Mechanical counter-pressure (MCP) space suits have the potential to greatly improve the mobility of astronauts as they conduct planetary exploration activities; however, the underlying technologies required to provide ...

  9. Design, construction and implementation of spherical tissue equivalent proportional counter

    E-Print Network [OSTI]

    Perez Nunez, Delia Josefina

    2009-05-15T23:59:59.000Z

    Tissue equivalent proportional counters (TEPC) are used for medical and space activities whenever a combination of high and low LET (lineal energy transfer) radiations are present. With the frequency and duration of space activities increasing...

  10. Aerodynamic performance measurements in a counter-rotating aspirated compressor

    E-Print Network [OSTI]

    Onnée, Jean-François

    2005-01-01T23:59:59.000Z

    This thesis is an experimental investigation of the aerodynamic performances of a counter-rotating aspirated compressor. This compressor is implemented in a blow-down facility, which gives rigorous simulation of the ...

  11. anticoincidence counter system: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    scattering of pumping light, which can be suppressed both by spatial and polarization filters. Motoaki Bamba; Cristiano Ciuti 2011-08-25 376 Jaynes-Cummings model:Counter...

  12. Full simulation of the Sudbury Neutrino Observatory proportional counters

    E-Print Network [OSTI]

    Beltran, B.

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of [superscript 3]He proportional counters to the detector. The purpose of this neutral-current detection (NCD) array was to observe ...

  13. Quarks and gluons in hadrons and nuclei

    SciTech Connect (OSTI)

    Close, F.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))

    1989-12-01T23:59:59.000Z

    These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. This lecture discusses the distribution functions of quarks and gluons in nucleons and nuclei, and how knowledge of these is necessary before some quark-gluon plasma searches can be analyzed. 56 refs., 2 figs.

  14. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22T23:59:59.000Z

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  15. Using DMA for copying performance counter data to memory

    DOE Patents [OSTI]

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W

    2013-12-31T23:59:59.000Z

    A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance data.

  16. ARM - Measurement - Ice nuclei

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSize Distributiontypes ARMnuclei

  17. Message passing with a limited number of DMA byte counters

    DOE Patents [OSTI]

    Blocksome, Michael (Rochester, MN); Chen, Dong (Croton on Hudson, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Kumar, Sameer (White Plains, NY); Parker, Jeffrey J. (Rochester, MN)

    2011-10-04T23:59:59.000Z

    A method for passing messages in a parallel computer system constructed as a plurality of compute nodes interconnected as a network where each compute node includes a DMA engine but includes only a limited number of byte counters for tracking a number of bytes that are sent or received by the DMA engine, where the byte counters may be used in shared counter or exclusive counter modes of operation. The method includes using rendezvous protocol, a source compute node deterministically sending a request to send (RTS) message with a single RTS descriptor using an exclusive injection counter to track both the RTS message and message data to be sent in association with the RTS message, to a destination compute node such that the RTS descriptor indicates to the destination compute node that the message data will be adaptively routed to the destination node. Using one DMA FIFO at the source compute node, the RTS descriptors are maintained for rendezvous messages destined for the destination compute node to ensure proper message data ordering thereat. Using a reception counter at a DMA engine, the destination compute node tracks reception of the RTS and associated message data and sends a clear to send (CTS) message to the source node in a rendezvous protocol form of a remote get to accept the RTS message and message data and processing the remote get (CTS) by the source compute node DMA engine to provide the message data to be sent.

  18. Electromagnetic reactions on light nuclei

    E-Print Network [OSTI]

    Sonia Bacca; Saori Pastore

    2014-07-13T23:59:59.000Z

    Electromagnetic reactions on light nuclei are fundamental to advance our understanding of nuclear structure and dynamics. The perturbative nature of the electromagnetic probes allows to clearly connect measured cross sections with the calculated structure properties of nuclear targets. We present an overview on recent theoretical ab-initio calculations of electron-scattering and photonuclear reactions involving light nuclei. We encompass both the conventional approach and the novel theoretical framework provided by chiral effective field theories. Because both strong and electromagnetic interactions are involved in the processes under study, comparison with available experimental data provides stringent constraints on both many-body nuclear Hamiltonians and electromagnetic currents. We discuss what we have learned from studies on electromagnetic observables of light nuclei, starting from the deuteron and reaching up to nuclear systems with mass number A=16.

  19. Photoproduction of mesons off nuclei

    E-Print Network [OSTI]

    B. Krusche

    2011-10-02T23:59:59.000Z

    Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets.

  20. Polarized EMC Effect in Nuclei

    SciTech Connect (OSTI)

    Ian Cloet; A. W. Thomas; W. Bentz

    2006-06-05T23:59:59.000Z

    The discovery of the EMC effect and the proton spin crisis by the European Muon Collaboration are two of the standout experiments of the last 25 years. It is therefore surprising that there has been no experimental and little theoretical investigation of the spin structure functions of atomic nuclei. To address this we present results for the spin-dependent structure functions of nuclei. The quark degrees of freedom in nuclei are accessed via the convolution formalism. Where the nucleon bound state is obtained by solving the relativistic Faddeev equation, and a relativistic shell model is used to model the atomic nucleus. We find the important result that the medium modifications to the polarized structure functions are about twice that of the unpolarized case.

  1. A Honeycomb Proportional Counter for Photon Multiplicity Measurement in the ALICE Experiment

    E-Print Network [OSTI]

    M. M. Aggarwal; S. K. Badyal; V. S. Bhatia; S. Chattopadhyay; A. K. Dubey; M. R. Dutta Majumdar; M. S. Ganti; P. Ghosh; A. Kumar; T. K. Nayak; S. Mahajan; D. P. Mahapatra; L. K. Mangotra; B. Mohanty; S. Pal; S. C. Phatak; B. V. K. S. Potukuchi; R. Raniwala; S. Raniwala; N. K. Rao; R. N. Singaraju; Bikash Sinha; M. D. Trivedi; R. J. Veenhof; Y. P. Viyogi

    2001-12-28T23:59:59.000Z

    A honeycomb detector consisting of a matrix of 96 closely packed hexagonal cells, each working as a proportional counter with a wire readout, was fabricated and tested at the CERN PS. The cell depth and the radial dimensions of the cell were small, in the range of 5-10 mm. The appropriate cell design was arrived at using GARFIELD simulations. Two geometries are described illustrating the effect of field shaping. The charged particle detection efficiency and the preshower characteristics have been studied using pion and electron beams. Average charged particle detection efficiency was found to be 98%, which is almost uniform within the cell volume and also within the array. The preshower data show that the transverse size of the shower is in close agreement with the results of simulations for a range of energies and converter thicknesses.

  2. Collisionless Shocks -- Magnetic Field Generation and Particle Acceleration

    E-Print Network [OSTI]

    J. Trier Frederiksen; C. B. Hededal; T. Haugboelle; A. Nordlund

    2003-03-16T23:59:59.000Z

    We present numerical results from plasma particle simulations of collisionless shocks and ultra-relativistic counter-streaming plasmas. We demonstrate how the field-particle interactions lead to particle acceleration behind the shock-front. Further, we demonstrate how ultra relativistic counter-streaming plasmas create large scale patchy magnetic field structures and that these field structures propagate down-stream of the shock front. These results may help explain the origin of the magnetic fields and accelerated electrons responsible for afterglow synchrotron radiation from gamma ray bursts.

  3. Transitional nuclei near shell closures

    SciTech Connect (OSTI)

    Mukherjee, G. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Pai, H. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064, India and Present Address: Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt (Germany)

    2014-08-14T23:59:59.000Z

    High spin states in Bismuth and Thallium nuclei near the Z = 82 shell closure and Cesium nuclei near the N = 82 shell closure in A = 190 and A = 130 regions, respectively, have been experimentally investigated using heavy-ion fusion evaporation reaction and by detecting the gamma rays using the Indian National Gamma Array (INGA). Interesting shape properties in these transitional nuclei have been observed. The results were compared with the neighboring nuclei in these two regions. The total Routhian surface (TRS) calculations have been performed for a better understanding of the observed properties. In mass region A = 190, a change in shape from spherical to deformed has been observd around neutron number N = 112 for the Bi (Z = 83) isotopes with proton number above the magic gap Z = 82, whereas, the shape of Tl (Z = 81) isotopes with proton number below the magic gap Z = 82 remains stable as a function of neutron number. An important transition from aplanar to planar configuration of angular momentum vectors leading to the occurance of nuclar chirality and magnetic rotation, respectively, has been proposed for the unique parity ?h{sub 11/2}??h{sub 11/2} configuration in Cs isotopes in the mass region A ? 130 around neutron number N = 79. These results are in commensurate with the TRS calculations.

  4. Generalized parton distributions of nuclei

    SciTech Connect (OSTI)

    Guzey, V. [Theory Center, Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

    2009-12-17T23:59:59.000Z

    We review recent theoretical results on generalized parton distributions (GPDs) of nuclei, emphasizing the following three roles of nuclear GPDs: (i) complementarity to free proton GPDs, (ii) the enhancement of traditional nuclear effects such nuclear binding, EMC effect, nuclear shadowing, and (iii) an access to novel nuclear effects such as medium modifications of bound nucleons.

  5. Boron-Lined Multichamber and Conventional Neutron Proportional Counter Tests

    SciTech Connect (OSTI)

    Woodring, Mitchell L.; Ely, James H.; Kouzes, Richard T.; Stromswold, David C.

    2010-09-07T23:59:59.000Z

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride (BF3)-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated non-scintillating plastic fibers. In addition, a few other companies have detector technologies that might be competitive in the near term as an alternative technology. Reported here are the results of tests of a boron-lined, multichamber proportional counter manufactured by LND, Inc. Also reported are results obtained with an earlier design of conventional, boron-lined, proportional counters from LND. This testing measured the required performance for neutron detection efficiency and gamma-ray rejection capabilities of the detectors.

  6. Pseudospin symmetry and structure of nuclei with $Z\\ge$ 100

    E-Print Network [OSTI]

    R. V. Jolos; V. V. Voronov

    2006-10-19T23:59:59.000Z

    In the framework of the Relativistic Mean Field Approach a pseudospin dependence of the residual forces in nuclei is considered. It is shown that this dependence is relatively weak. As a consequence, a pseudospin dependence of the particle--core coupling is weak as well. This leads to a small splitting of the pseudospin doublets produced by a vector coupling of an odd particle pseudospin and a pseudo--orbital momentum of the core. Some possibilities for experimental investigations of the manifestations of the pseudospin symmetry in the spectra of odd nuclei with $Z\\ge$ 100 are indicated.

  7. alpha-particle condensed state: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  8. alpha-particle emitter 211at: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  9. alpha-particle mediated depletion: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  10. Fabrication of silica aerogel with $n$ = 1.08 for $e^+/?^+$ separation in a threshold Cherenkov counter of the J-PARC TREK/E36 experiment

    E-Print Network [OSTI]

    Makoto Tabata; Akihisa Toyoda; Hideyuki Kawai; Youichi Igarashi; Jun Imazato; Suguru Shimizu; Hirohito Yamazaki

    2015-06-09T23:59:59.000Z

    This study presents the development of hydrophobic silica aerogel for use as a radiator in threshold-type Cherenkov counters. These counters are to be used for separating positrons and positive muons produced by kaon decay in the J-PARC TREK/E36 experiment. We chose to employ aerogel with a refractive index of 1.08 to identify charged particles with momenta of approximately 240 MeV/$c$, and the radiator block shape was designed with a trapezoidal cross-section to fit the barrel region surrounding the kaon stopping target in the center of the TREK/E36 detector system. Including spares, we obtained 30 crack-free aerogel blocks segmented into two layers, each layer having a thickness of 2 cm and a length of 18 cm, to fill 12 counter modules. Optical measurements showed that the produced aerogel tiles had the required refractive indices and transparency.

  11. $^8$He nuclei stopped in nuclear track emulsion

    E-Print Network [OSTI]

    D. A. Artemenkov; A. A. Bezbakh; V. Bradnova; M. S. Golovkov; A. V. Gorshkov; G. Kaminsky; N. K. Kornegrutsa; S. A. Krupko; K. Z. Mamatkulov; R. R. Kattabekov; V. V. Rusakova; R. S. Slepnev; R. Stanoeva; S. V. Stepantsov; A. S. Fomichev; V. Chudoba; P. I. Zarubin; I. G. Zarubina

    2014-10-20T23:59:59.000Z

    The fragment separator ACCULINNA in the G. N. Flerov Laboratory of Nuclear Reactions of JINR was used to expose a nuclear track emulsion to a beam of radioactive $^{8}$He nuclei of energy of 60 MeV and enrichment of about 80%. Measurements of decays of $^{8}$He nuclei stopped in the emulsion allow one to evaluate possibilities of $\\alpha$-spectrometry and to observe a thermal drift of $^{8}$He atoms in matter. Knowledge of the energy and emission angles of $\\alpha$-particles allows one to derive the energy distribution of $\\alpha$-decays Q$_{2\\alpha}$. The presence of a "tail" of large values Q$_{2\\alpha}$ is established. The physical reason for the appearance of this "tail" in the distribution Q$_{2\\alpha}$ is not clear. Its shape could allow one to verify calculations of spatial structure of nucleon ensembles emerging as $\\alpha$-pairs of decays via the state $^8$Be$_{2+}$.

  12. Nuclear Alpha-Particle Condensates

    E-Print Network [OSTI]

    T. Yamada; Y. Funaki; H. Horiuchi; G. Roepke; P. Schuck; A. Tohsaki

    2011-03-21T23:59:59.000Z

    The $\\alpha$-particle condensate in nuclei is a novel state described by a product state of $\\alpha$'s, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical $\\alpha$-particle condensate is the Hoyle state ($E_{x}=7.65$ MeV, $0^+_2$ state in $^{12}$C), which plays a crucial role for the synthesis of $^{12}$C in the universe. The influence of antisymmentrization in the Hoyle state on the bosonic character of the $\\alpha$ particle is discussed in detail. It is shown to be weak. The bosonic aspects in the Hoyle state, therefore, are predominant. It is conjectured that $\\alpha$-particle condensate states also exist in heavier $n\\alpha$ nuclei, like $^{16}$O, $^{20}$Ne, etc. For instance the $0^+_6$ state of $^{16}$O at $E_{x}=15.1$ MeV is identified from a theoretical analysis as being a strong candidate of a $4\\alpha$ condensate. The calculated small width (34 keV) of $0^+_6$, consistent with data, lends credit to the existence of heavier Hoyle-analogue states. In non-self-conjugated nuclei such as $^{11}$B and $^{13}$C, we discuss candidates for the product states of clusters, composed of $\\alpha$'s, triton's, and neutrons etc. The relationship of $\\alpha$-particle condensation in finite nuclei to quartetting in symmetric nuclear matter is investigated with the help of an in-medium modified four-nucleon equation. A nonlinear order parameter equation for quartet condensation is derived and solved for $\\alpha$ particle condensation in infinite nuclear matter. The strong qualitative difference with the pairing case is pointed out.

  13. Experimental level-structure determination in odd-odd actinide nuclei

    SciTech Connect (OSTI)

    Hoff, R.W.

    1985-04-04T23:59:59.000Z

    The status of experimental determination of level structure in odd-odd actinide nuclei is reviewed. A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei is applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation are derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings are used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Applications of this modeling technique are discussed.

  14. A Combined Neutron and Gamma-Ray Multiplicity Counter Based on Liquid Scintillation Detectors

    SciTech Connect (OSTI)

    Andreas Enqvist; Marek Flaska; Jennifer Dolan; David L. Chichester; Sara A. Pozzi

    2011-10-01T23:59:59.000Z

    Multiplicity counters for neutron assay have been extensively used in materials control and accountability for nonproliferation and nuclear safeguards. Typically, neutron coincidence counters are utilized in these fields. In this work, we present a measurement system that makes use not only of neutron (n) multiplicity counting but also of gamma-ray (g) multiplicity counting and the combined higher-order multiples containing both neutrons and gamma rays. The benefit of this approach is in using both particle types available from the sample, leading to a reduction in measurement times needed when using more measurables. We present measurement results of n, g, nn, ng, gg, nnn, nng, ngg, and ggg multiples emitted by Mixed-Oxide (MOX) samples measured at Idaho National Laboratory (INL). The MOX measurement is compared to initial validation of the detection system done using a 252Cf source. The dual radiation measuring system proposed here uses extra measurables to improve the statistics when compared to a neutron-only system and allows for extended analysis and interpretation of sample parameters. New challenges such as the effect of very high intrinsic gamma-ray sources in the case of MOX samples is discussed. Successful measurements of multiples rates can be performed also when using high-Z shielding.

  15. Compton Scattering on Light Nuclei

    E-Print Network [OSTI]

    Deepshikha Shukla

    2009-12-22T23:59:59.000Z

    Compton scattering on light nuclei ($A=2,3$) has emerged as an effective avenue to search for signatures of neutron polarizabilities, both spin--independent and spin--dependent ones. In this discussion I will focus on the theoretical aspect of Compton scattering on light nuclei; giving first a brief overview and therafter concentrating on our Compton scattering calculations based on Chiral effective theory at energies of the order of pion mass. These elastic $\\gamma$d and $\\gamma$He-3 calculations include nucleons, pions as the basic degrees of freedom. I will also discuss $\\gamma$d results where the $\\Delta$-isobar has been included explicitly. Our results on unpolarized and polarization observables suggest that a combination of experiments and further theoretical efforts will provide an extraction of the neutron polarizabilities.

  16. Structure functions for light nuclei

    SciTech Connect (OSTI)

    S.A. Kulagin, R. Petti

    2010-11-01T23:59:59.000Z

    We discuss the nuclear EMC effect with particular emphasis on recent data for light nuclei including 2H, 3He, 4He, 9Be, 12C and 14N. In order to verify the consistency of available data, we calculate the \\chi^2 deviation between different data sets. We find a good agreement between the results from the NMC, SLAC E139, and HERMES experiments. However, our analysis indicates an overall normalization offset of about 2% in the data from the recent JLab E03-103 experiment with respect to previous data for nuclei heavier than 3He. We also discuss the extraction of the neutron/proton structure function ratio F2n/F2p from the nuclear ratios 3He/2H and 2H/1H. Our analysis shows that the E03-103 data on 3He/2H require a renormalization of about 3% in order to be consistent with the F2n/F2p ratio obtained from the NMC experiment. After such a renormalization, the 3He data from the E03-103 data and HERMES experiments are in a good agreement. Finally, we present a detailed comparison between data and model calculations, which include a description of the nuclear binding, Fermi motion and off-shell corrections to the structure functions of bound proton and neutron, as well as the nuclear pion and shadowing corrections. Overall, a good agreement with the available data for all nuclei is obtained.

  17. Counter-rotating Kerr manifolds separated by a fluid shell

    E-Print Network [OSTI]

    J. P. Krisch; E. N. Glass

    2009-08-13T23:59:59.000Z

    We describe a spheroidal fluid shell between two Kerr vacuum regions which have opposite rotation parameters. The shell has a stiff equation of state and a heat flow vector related to the rotational Killing current. The shell description is useful in exploring the significance of counter-rotation in Kerr metric matches.

  18. Production-Run Software Failure Diagnosis via Hardware Performance Counters

    E-Print Network [OSTI]

    Sheridan, Jennifer

    Production-Run Software Failure Diagnosis via Hardware Performance Counters Joy Arulraj Po and huge financial loss during production runs. Tools that diagnose production-run failures with low is sometimes over 100%, for concurrency-bug failure diagnosis and hence are not suitable for production

  19. Boundary geometric control of a counter-current heat exchanger

    E-Print Network [OSTI]

    Boyer, Edmond

    control of a counter-current heat exchanger whose control is designed considering a model based on two differential equation describing the temperature of the internal fluid, and the manipulated control regulation and tracking performances. The robustness of the controller has also been studied when velocities

  20. Transition-Transversion Bias Is Not Universal: A Counter Example

    E-Print Network [OSTI]

    Bensasson, Douda

    Transition-Transversion Bias Is Not Universal: A Counter Example from Grasshopper Pseudogenes Irene of transitional over transversional substitutions. Part of this bias is due to the relatively high rate, that there is a universal bias in favour of transitions over transversions, possibly as a result of the underlying chemistry

  1. Shift-register coincidence electronics system for thermal neutron counters

    SciTech Connect (OSTI)

    Swansen, J.E.; Collinsworth, P.R.; Krick, M.S.

    1980-04-01T23:59:59.000Z

    An improved shift-register, coincidence-counting logic circuit, developed for use with thermal neutron well counters, is described in detail. A distinguishing feature of the circuit is its ability to operate usefully at neutron counting rates of several hundred kHz. A portable electronics package incorporating the new coincidence logic and support circuits is also described.

  2. Confronting Nuclear Risks: Counter-Expertise as Politics Within

    E-Print Network [OSTI]

    Gutkin, Boris

    Confronting Nuclear Risks: Counter-Expertise as Politics Within the French Nuclear Energy Debate of knowledge and expertise on the environ- mental and health risks of nuclear energy in France. From disaster (26 April 1986). Since then, the biggest nuclear accident ever has added par- ticular significance

  3. Design and Performance of a Silicon Test Counter for HERMES

    E-Print Network [OSTI]

    -detector array has been designed and constructed to investigate the prospects for large-angle trackingDesign and Performance of a Silicon Test Counter for HERMES J. Visser a , M.G. van Beuzekom a , J. For the read-out, a local front-end with 64-channel Analog Pipeline Chips (APC) has been employed. The large

  4. Boron-Lined Multitube Neutron Proportional Counter Test

    SciTech Connect (OSTI)

    Woodring, Mitchell L.; Ely, James H.; Kouzes, Richard T.; Stromswold, David C.

    2010-09-07T23:59:59.000Z

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride (BF3)-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated non-scintillating plastic fibers. In addition, a few other companies have detector technologies that might be competitive in the near term as an alternative technology. Reported here are the results of tests of a boron-lined, “multitube” proportional counter manufactured by Centronic Ltd. (Surry, U.K. and Houston, TX). This testing measured the required performance for neutron detection efficiency and gamma-ray rejection capabilities of the detector.

  5. Hybrid Secret Key Escrow Mechanisms as Counters Esa Hyytia

    E-Print Network [OSTI]

    Hyytiä, Esa

    Hybrid Secret Key Escrow Mechanisms as Counters Esa Hyyti¨a Telecommunications Research Center can be used in several ways. One interesting application of the Shamir's secret sharing scheme in the context of privacy aware traffic monitoring is to escrow a secret key after m suspicious events have been

  6. Electromagnetic counterparts from counter-rotating relativistic kicked discs

    E-Print Network [OSTI]

    Olindo Zanotti

    2011-08-23T23:59:59.000Z

    We show the results of two dimensional general relativistic inviscid and isothermal hydrodynamical simulations comparing the behavior of co-rotating (with respect to the black hole rotation) and counter-rotating circumbinary quasi-Keplerian discs in the post merger phase of a supermassive binary black hole system. While confirming the spiral shock generation within the disc due to the combined effects of mass loss and recoil velocity of the black hole, we find that the maximum luminosity of counter-rotating discs is a factor ~(2-12) higher than in the co-rotating case, depending on the spin of the black hole. On the other hand, the luminosity peak happens ~10 days later with respect to the co-rotating case, for a binary with a total mass M~10^6 M_\\odot. Although the global dynamics of counter-rotating discs in the post merger phase of a merging event is very similar to that for co-rotating discs, an important difference has been found. In fact, increasing the spin of the central black hole produces more luminous co-rotating discs while less luminous counter-rotating ones.

  7. Master Thesis Ring Imaging Cerenkov Counter with Aerogel

    E-Print Network [OSTI]

    [a4]report #12; i Master Thesis Ring Imaging Cerenkov Counter with Aerogel Radiator for HERMES;, k, p in all the HERMES engergy region: 2 GeV to 20 GeV. The new RICH system uses aerogel and C 4 F 10 gas as its Cerenkov radiator. The refractive index and other properties of all the aerogel tiles

  8. BABYSCAN - a whole body counter for small children in Fukushima

    E-Print Network [OSTI]

    Hayano, Ryugo S; Bronson, Frazier L; Oginni, Babatunde; Muramatsu, Isamu

    2014-01-01T23:59:59.000Z

    BABYSCAN, a whole body counter for small children with a detection limit for $^{137}$Cs of better than 50 Bq/body, was developed, and the first unit has been installed at a hospital in Fukushima, to help families with small children who are very much concerned about internal exposures. The design principles, implementation details and the initial operating experience are described.

  9. Chemical aging of single and multicomponent biomass burning aerosol surrogate-particles by OH: Implications for cloud condensation nucleus activity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Thalman, R.; Thalman, R.; Wang, J.; Knopf, D. A.

    2015-01-01T23:59:59.000Z

    Multiphase OH and O? oxidation reactions with atmospheric organic aerosol (OA) can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low soluble single-component OA by OH and O? can increase their water-solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN) and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water-solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA) surrogate-particles exposed to OH andmore »O? is evaluated by determining the hygroscopicity parameter, ?, as a function of particle type, mixing state, and OH/O? exposure applying a CCN counter (CCNc) coupled to an aerosol flow reactor (AFR). Levoglucosan (LEV), 4-methyl-5-nitrocatechol (MNC), and potassium sulfate (KS) serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O? exposure. Following exposure to OH, ? of MNC was enhanced by an order of magnitude, from 0.009 to ~0.1, indicating that chemically-aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in ? was observed for pure LEV particles following OH exposure. ? of the internally-mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH exposed MNC-coated KS particles is similar to the OH unexposed atomized 1:1 by mass MNC: KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC) or inorganic ions, chemical aging has no significant impact on OA hygroscopicity. The organic compounds exhibiting low solubility behave as if they are infinitely soluble when mixed with a sufficient amount of water-soluble compounds. At and beyond this point, the particles' CCN activity is governed entirely by the water-soluble fraction and not influenced by the oxidized organic fraction. Our results have important implications for heterogeneous oxidation and its impact on cloud formation given that atmospheric aerosol is a complex mixture of organic and inorganic compounds exhibiting a wide-range of solubilities.« less

  10. Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny

    E-Print Network [OSTI]

    Yu, K.N.

    Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny in the human Abstract To calculate the absorbed dose in the human lung due to inhaled radon progeny, ICRP focussed and secretory cells). The absorbed energy for alpha particles emitted by radon progeny in the human respiratory

  11. Neutron coincidence counter for MOX fuel pins in storage trays: users' manual

    SciTech Connect (OSTI)

    Cowder, L.; Menlove, H.

    1982-08-01T23:59:59.000Z

    The neutron coincidence counter for measurement of mixed-oxide fuel pins in storage trays is described. The special detector head has been designed so that the detectors, high-voltage junction boxes, and electronics are interchangeable with those of the high-level neutron coincidence counter system. This manual describes the system components and the operation and maintenance of the counter. The counter was developed at Los Alamos National Laboratory for in-plant inspection applications by the International Atomic Energy Agency.

  12. Study of electromagnetic dissociation of heavy nuclei at the relativistic heavy ion collider

    E-Print Network [OSTI]

    Makeev, Andrei

    2001-01-01T23:59:59.000Z

    LIST OF FIGURES FIGURE Page RHIC accelerator facility. Top view of the BRAHMS detectors and magnets. BRAHMS beam-beam counter arrays. The points are particles from GEANT simulations hitting the active detector volumes. . . . 11 Silicon strip... Calculated response of the ZDC to protons, electrons and muons. . . 22 ZDC module-photomultiplier assembly. 24 W-Cherenkov ZDC prototype spectra when hit with 100 and 160 GeV protons at CERN. 26 10 Measured ZDC energy resolution versus energy. 28 Because...

  13. Dual Origin of Pairing in Nuclei

    E-Print Network [OSTI]

    A. Idini; G. Potel; F. Barranco; E. Vigezzi; R. A. Broglia

    2014-04-29T23:59:59.000Z

    An essentially "complete" description of the low-energy nuclear structure of the superfluid nucleus $^{120}$Sn and of its odd-$A$ neighbors is provided by the observations carried out with the help of Coulomb excitation and of one-- and of two-- particle transfer reactions, specific probes of vibrations, quasiparticle and pairing degrees of freedom respectively, and of their mutual couplings. These experimental findings are used to stringently test the predictions of a similarly "complete" description of $^{119,120,121}$Sn carried out in terms of elementary modes of excitation which, through their interweaving, melt together into effective fields, each displaying properties reflecting that of all others, there individuality resulting from the actual relative importance of each one. Its implementation is done by solving the Nambu-Gor'kov equations including, for the first time, all medium polarization effects resulting from the interweaving of quasiparticles, spin and surface vibrations, taking into account, within the framework of nuclear field theory (NFT), the variety of processes leading to self-energy, vertex and Pauli principle corrections, and to the induced pairing interaction. Theory provides an overall quantitative account of the experimental findings. From these results one can, not only obtain strong circumstantial evidence for the inevitability for the dual origin of pairing in nuclei but also, extract information which can be used at profit to quantitatively disentangle the contributions to pairing correlations in general and to the pairing gap in particular, arising from the bare and from the induced pairing interactions.

  14. Structure functions for light nuclei

    SciTech Connect (OSTI)

    Kulagin, S. A. [Institute for Nuclear Research of the Russian Academy of Sciences, 117312 Moscow (Russian Federation); Petti, R. [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States)

    2010-11-15T23:59:59.000Z

    We discuss the nuclear EMC effect with particular emphasis on recent data for light nuclei including {sup 2}H, {sup 3}He, {sup 4}He, {sup 9}Be, {sup 12}C, and {sup 14}N. In order to verify the consistency of available data, we calculate the {chi}{sup 2} deviation between different data sets. We find a good agreement between the results from the NMC, SLAC E139, and HERMES experiments. However, our analysis indicates an overall normalization offset of about 2% in the data from the recent JLab E03-103 experiment with respect to previous data for nuclei heavier than {sup 3}He. We also discuss the extraction of the neutron/proton structure function ratio F{sub 2}{sup n}/F{sub 2}{sup p} from the nuclear ratios {sup 3}He/{sup 2}H and {sup 2}H/{sup 1}H. Our analysis shows that the E03-103 data on {sup 3}He/{sup 2}H require a renormalization of about 3% in order to be consistent with the F{sub 2}{sup n}/F{sub 2}{sup p} ratio obtained from the NMC experiment. After such a renormalization, the {sup 3}He data from the E03-103 and HERMES experiments are in a good agreement. Finally, we present a detailed comparison between data and model calculations, which include a description of the nuclear binding, Fermi motion, and off-shell corrections to the structure functions of bound proton and neutron, as well as the nuclear pion and shadowing corrections. Overall, a good agreement with the available data for all nuclei is obtained.

  15. INTERACTION OF NUCLEI AT HIGH ENERGIES

    E-Print Network [OSTI]

    Steiner, Herbert.

    2010-01-01T23:59:59.000Z

    Production on Nuclei. Trieste (June, 1976) 4) T.D. Lee,Energies, S.A. Azimov, ed •• Trieste, June, 1976 30) H.H.

  16. Temperature-Dependent Fission Barriers of Superheavy Nuclei

    E-Print Network [OSTI]

    Pei, J C; Sheikh-Javid, A; Kerman, A K

    2009-01-01T23:59:59.000Z

    The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. We study the temperature-dependent fission barriers by means of the self-consistent nuclear density functional theory. The equivalence of isothermal and isentropic descriptions is demonstrated. The effect of the particle gas is found to be negligible in the range of temperatures studied. Calculations have been carried out for $^{264}$Fm, $^{272}$Ds, $^{278}$112, $^{292}$114, and $^{312}$124. For nuclei around $^{278}$112 produced in "cold fusion" reactions, we predict a more rapid decrease of fission barriers with temperature as compared to the nuclei around $^{292}$114 synthesized in "hot fusion" experiments. This is explained in terms of the difference between the ground-state and fission-barrier temperatures. Our calculations are consistent with the long survival probabilities of the superheavy elements produced in Dubna with th...

  17. Neutron Dripline in Odd and Even Mass Calcium and Nickel Nuclei

    E-Print Network [OSTI]

    Madhubrata Bhattacharya; G. Gangopadhyay

    2005-09-21T23:59:59.000Z

    Neutron rich Ca and Ni nuclei have been studied in spherical Relativistic Mean Field formalism in co-ordinate space. A delta interaction has been has been adopted to treat the pairing correlations for the neutrons. Odd nuclei have been treated in the blocking approximation. The effect of the positive energy continuum and the role of pairing in the stability of nuclei have been investigated using the resonant-BCS (rBCS) approach. In Ca isotopes, N=50 is no longer a magic number while in Ni nuclei, a new magic number emerges at N=70. There is a remarkable difference in the relative positions of the drip lines for odd and even isotopes. In Ca isotopes, the last bound even and odd nuclei are found to be $^{72}$Ca and $^{59}$Ca, respectively. In Ni isotopes, the corresponding nuclei are $^{98}$Ni and $^{97}$Ni, respectively. The origin of this difference in relative positions of the dripline in even and odd isotopes in the two chain is traced to the difference in the single particle level structures and consequent modification in the magic numbers in the two elements. Pairing interaction is seen to play a major role. The effect of the width of the resonance states on pairing has also been investigated.

  18. Constraints on Particle Acceleration from the Diffuse Isotropic Gamma-Ray Background

    E-Print Network [OSTI]

    Karl Mannheim

    2000-05-26T23:59:59.000Z

    Gamma rays trace accelerated particles, and the observed flux of extragalactic gamma rays therefore constrains the global efficiency for particle acceleration. Extragalactic jets in active galactic nuclei can account for the gamma ray background if their particle acceleration efficiency considerably exceeds ~ 18 per cent which would imply that particle acceleration is an essential part of the thermodynamics in these sources.

  19. Visible light photon counters optimization for quantum information applications

    SciTech Connect (OSTI)

    Molina, J.; /Rio de Janeiro State U.; Estrada, J.; Bross, A.; /Fermilab; Ginther, G.; /Rochester U.; Buscher, V.; /Freiburg U.

    2006-10-01T23:59:59.000Z

    In this paper we describe the studies of the main parameters needed for optimal operation of Visible Light Photon Counters (VLPCs) when used in quantum information systems. The isolation of the single photon signal is analyzed through the definition of a contamination parameter. A compromise in the minimization of this parameter for temperature, bias voltage and dark count variation must be achieved and this depends on the experimental conditions.

  20. On spectroscopic factors of magic and semimagic nuclei

    SciTech Connect (OSTI)

    Saperstein, E. E. [Kurchatov Institute, 123182 Moscow (Russian Federation); Gnezdilov, N. V. [Kurchatov Institute, 123182 Moscow, Russia and National Research Nuclear University MEPhI, 115409 Moscow (Russian Federation); Tolokonnikov, S. V. [Kurchatov Institute, 123182 Moscow, Russia and Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation)

    2014-10-15T23:59:59.000Z

    Single-particle spectroscopic factors (SF) of magic and semimagic nuclei are analyzed within the self-consistent theory of finite Fermi systems. The the in-volume energy dependence of the mass operator ? is taken into account in addition to the energy dependence induced by the surface-phonon coupling effects which is commonly considered. It appears due to the effect of high-lying collective and non-collective particle-hole excitations and persists in nuclear matter. The self-consistent basis of the energy density functional method by Fayans et al. is used. Both the surface and in-volume contributions to the SFs turned out to be of comparable magnitude. Results for magic {sup 208}Pb nucleus and semimagic lead isotopes are presented.

  1. Critical analysis of quark-meson coupling models for nuclear matter and finite nuclei

    E-Print Network [OSTI]

    Horst Mueller; Byron K. Jennings

    1998-07-09T23:59:59.000Z

    Three versions of the quark-meson coupling (QMC) model are applied to describe properties of nuclear matter and finite nuclei. The models differ in the treatment of the bag constant and in terms of nonlinear scalar self-interactions. As a consequence opposite predictions for the medium modifications of the internal nucleon structure arise. After calibrating the model parameters at equilibrium nuclear matter density, binding energies, charge radii, single-particle spectra and density distributions of spherical nuclei are analyzed and compared with QHD calculations. For the models which predict a decreasing size of the nucleon in the nuclear environment, unrealistic features of the nuclear shapes arise.

  2. Nuclei embedded in an electron gas

    E-Print Network [OSTI]

    Thomas J. Buervenich; Igor N. Mishustin; Walter Greiner

    2007-06-11T23:59:59.000Z

    The properties of nuclei embedded in an electron gas are studied within the relativistic mean-field approach. These studies are relevant for nuclear properties in astrophysical environments such as neutron-star crusts and supernova explosions. The electron gas is treated as a constant background in the Wigner-Seitz cell approximation. We investigate the stability of nuclei with respect to alpha and beta decay. Furthermore, the influence of the electronic background on spontaneous fission of heavy and superheavy nuclei is analyzed. We find that the presence of the electrons leads to stabilizing effects for both $\\alpha$ decay and spontaneous fission for high electron densities. Furthermore, the screening effect shifts the proton dripline to more proton-rich nuclei, and the stability line with respect to beta decay is shifted to more neutron-rich nuclei. Implications for the creation and survival of very heavy nuclear systems are discussed.

  3. Relativistic Shocks: Particle Acceleration and Magnetization

    E-Print Network [OSTI]

    Sironi, Lorenzo; Lemoine, Martin

    2015-01-01T23:59:59.000Z

    We review the physics of relativistic shocks, which are often invoked as the sources of non-thermal particles in pulsar wind nebulae (PWNe), gamma-ray bursts (GRBs), and active galactic nuclei (AGN) jets, and as possible sources of ultra-high energy cosmic-rays. We focus on particle acceleration and magnetic field generation, and describe the recent progress in the field driven by theory advances and by the rapid development of particle-in-cell (PIC) simulations. In weakly magnetized or quasi parallel-shocks (where the magnetic field is nearly aligned with the flow), particle acceleration is efficient. The accelerated particles stream ahead of the shock, where they generate strong magnetic waves which in turn scatter the particles back and forth across the shock, mediating their acceleration. In contrast, in strongly magnetized quasi-perpendicular shocks, the efficiencies of both particle acceleration and magnetic field generation are suppressed. Particle acceleration, when efficient, modifies the turbulence ...

  4. Fabrication of solar cells with counter doping prevention

    DOE Patents [OSTI]

    Dennis, Timothy D; Li, Bo; Cousins, Peter John

    2013-02-19T23:59:59.000Z

    A solar cell fabrication process includes printing of dopant sources over a polysilicon layer over backside of a solar cell substrate. The dopant sources are cured to diffuse dopants from the dopant sources into the polysilicon layer to form diffusion regions, and to crosslink the dopant sources to make them resistant to a subsequently performed texturing process. To prevent counter doping, dopants from one of the dopant sources are prevented from outgassing and diffusing into the other dopant source. For example, phosphorus from an N-type dopant source is prevented from diffusing to a P-type dopant source comprising boron.

  5. Measurement of photon correlations with multipixel photon counters

    E-Print Network [OSTI]

    Dmitry Kalashnikov; Leonid A. Krivitsky

    2014-08-01T23:59:59.000Z

    Development of reliable photon number resolving detectors (PNRD), devices which are capable to distinguish 1,2,3.. photons, is of a great importance for quantum optics and its applications. A new class of affordable PNRD is based on multipixel photon counters (MPPC). Here we review results of experiments on using MPPCs for direct characterization of squeezed vacuum (SV) states, generated via parametric downconversion (PDC). We use MPPCs to measure the second order normalized intensity correlation function (g^(2)) and directly detect the two-mode squeezing of SV states. We also present a method of calibration of crosstalk probability in MPPCs based on g^(2) measurements of coherent states.

  6. Ab initio Bogoliubov coupled cluster theory for open-shell nuclei

    E-Print Network [OSTI]

    Angelo Signoracci; Thomas Duguet; Gaute Hagen; Gustav Jansen

    2014-12-08T23:59:59.000Z

    Ab initio many-body methods address closed-shell nuclei up to mass A ~ 130 on the basis of realistic two- and three-nucleon interactions. Several routes to address open-shell nuclei are currently under investigation, including ideas which exploit spontaneous symmetry breaking. Singly open-shell nuclei can be efficiently described via the sole breaking of $U(1)$ gauge symmetry associated with particle number conservation, to account for their superfluid character. The present work formulates and applies Bogoliubov coupled cluster (BCC) theory, which consists of representing the exact ground-state wavefunction of the system as the exponential of a quasiparticle excitation cluster operator acting on a Bogoliubov reference state. Equations for the ground-state energy and cluster amplitudes are derived at the singles and doubles level (BCCSD) both algebraically and diagrammatically. The formalism includes three-nucleon forces at the normal-ordered two-body level. The first BCC code is implemented in $m$-scheme, which will eventually permit the treatment of doubly open-shell nuclei. Proof-of-principle calculations in an $N_{\\text{max}}=6$ spherical harmonic oscillator basis are performed for $^{16,18,20}$O, $^{18}$Ne, $^{20}$Mg in the BCCD approximation with a chiral two-nucleon interaction, comparing to results obtained in standard coupled cluster theory when applicable. The breaking of $U(1)$ symmetry is monitored by computing the variance associated with the particle-number operator. The newly developed many-body formalism increases the potential span of ab initio calculations based on single-reference coupled cluster techniques tremendously, i.e. potentially to reach several hundred additional mid-mass nuclei. The new formalism offers a wealth of potential applications and further extensions dedicated to the description of ground and excited states of open-shell nuclei.

  7. Development of large flow counters for detection of low intensity cosmic ray particles

    E-Print Network [OSTI]

    Bull, Kenneth Winson

    1965-01-01T23:59:59.000Z

    the fluorescent tubing for use as Geiger envelopes, one must use extreme care. The white coating contains beryllium zinc silicate which is toxic if brought into contact with the mucous membranes. The glass is also very brittle and therefore gloves should... be obtained in various sizes and is strong, unifozm in cross section, and smooth. It has the disadvantage, however, that it cannot be soft soldezed. For this reason, the tungsten is first spot welded to some nickel-silver wire at each end. Then the nickel...

  8. THE INFLUENCE OF INELASTIC NEUTRINO REACTIONS WITH LIGHT NUCLEI ON THE STANDING ACCRETION SHOCK INSTABILITY IN CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Furusawa, Shun; Nagakura, Hiroki; Yamada, Shoichi [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan); Sumiyoshi, Kohsuke, E-mail: furusawa@heap.phys.waseda.ac.jp [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan)

    2013-09-01T23:59:59.000Z

    We perform numerical experiments to investigate the influence of inelastic neutrino reactions with light nuclei on the standing accretion shock instability (SASI). The time evolution of shock waves is calculated with a simple light-bulb approximation for the neutrino transport and a multi-nuclei equation of state. The neutrino absorptions and inelastic interactions with deuterons, tritons, helions, and alpha particles are taken into account in the hydrodynamical simulations. In addition, the effects of ordinary charged-current interactions with nucleons is addressed in the simulations. Axial symmetry is assumed but no equatorial symmetry is imposed. We show that the heating rates of deuterons reach as high as {approx}10% of those of nucleons around the bottom of the gain region. On the other hand, alpha particles are heated near the shock wave, which is important when the shock wave expands and the density and temperature of matter become low. It is also found that the models with heating by light nuclei evolve differently in the non-linear phase of SASI than do models that lack heating by light nuclei. This result is because matter in the gain region has a varying density and temperature and therefore sub-regions appear that are locally rich in deuterons and alpha particles. Although the light nuclei are never dominant heating sources and they work favorably for shock revival in some cases and unfavorably in other cases, they are non-negligible and warrant further investigation.

  9. From Nucleons To Nuclei To Fusion Reactions

    SciTech Connect (OSTI)

    Quaglioni, S; Navratil, P; Roth, R; Horiuchi, W

    2012-02-15T23:59:59.000Z

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  10. Calibration and assessment of a unique standup moving detector whole body counter

    E-Print Network [OSTI]

    Mallett, Michael Wesley

    1990-01-01T23:59:59.000Z

    whole body counters 57 Table 13: Physical characteristics of selected whole body counters Table 14: Comparison of MDA with il- source present for ANSI N343 list of radionuclides 62 73 Table 15: Comparison of MDA for a 5% reduction in count time...' ACKNOWLEDGEMENTS DEDICATION TABLE OF CONTENTS . LIST OF FIGURES . LIST OF TABLES INTRODUCTION HISTORY OF WHOLE BODY COUNTING UNIVERSAL BODY COUNTER DESIGN TESTING OB JECTIVES . ANSI N343 . ANSI N13. 30 . Selection of ANSI N13. 30 Calibration Method...

  11. Helium nuclei around the neutron drip line

    E-Print Network [OSTI]

    Madhubrata Bhattacharya; G. Gangopadhyay; Subinit Roy

    2012-03-10T23:59:59.000Z

    Neutron rich He nuclei have been investigated using relativistic mean field approach in co-ordinate space. Elastic partial scattering cross sections for proton scattering in inverse kinematics have been calculated using the theoretically obtained density for $^{6,8}$He and compared with experiment. The energies of the low-lying resonance states in the neutron unstable nuclei $^{5,7}$He have also been calculated and compared with experimental observations.

  12. Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

    SciTech Connect (OSTI)

    Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond J.; /Fermilab

    2010-11-01T23:59:59.000Z

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  13. European Journal of Soil Science, December 2010, 61, 854864 doi: 10.1111/j.1365-2389.2010.01298.x Revisiting the particle-size distribution of soils

    E-Print Network [OSTI]

    Ahmad, Sajjad

    (PP) sedimenta- tion/settling velocity, Micromeritics SediGraph (MS) sedimentation/x-ray attenuation and Coulter Counter (CC) electroresistance particle counting. The Malvern Mastersizer (MM), an instrument

  14. The Fractal Geometrical Properties of Nuclei

    E-Print Network [OSTI]

    W. H. Ma; J. S. Wang; Q. Wang; S. Mukherjee; L. Yang; Y. Y. Yang; M. R. Huang; Y. J. Zhou

    2014-06-06T23:59:59.000Z

    We present a new idea to understand the structure of nuclei, which is comparing to the liquid drop model. After discussing the probability that the nuclear system may be a fractal object with the characteristic of self-similarity, the nuclear irregular structure properties and the self-similarity characteristic are considered to be an intrinsic aspects of nuclear structure properties. For the description of nuclear geometric properties, nuclear fractal dimension is an irreplaceable variable similar to the nuclear radius. In order to determine these two variables, a new nuclear potential energy formula which is related to the fractal dimension is put forward and the phenomenological semi-empirical Bethe-Weizsacker binding energy formula is modified using the fractal geometric theory. And one important equation set with two equations is obtained, which is related to the conception that the fractal dimension should be a dynamical parameter in the process of nuclear synthesis. The fractal dimensions of the light nuclei are calculated and their physical meanings are discussed. We have compared the nuclear fractal mean density radii with the radii calculated by the liquid drop model for the light stable and unstable nuclei using rational nuclear fractal structure types. In the present model of fractal nuclear structure there is an obvious feature comparing to the liquid drop model, since the present model can reflect the geometric informations of the nuclear structure, especially for the nuclei with clusters, such as the {\\alpha}-cluster nuclei and halo nuclei.

  15. Reporting Prescription Drugs, Over-the-Counter Medications, and Dietary Supplements

    SciTech Connect (OSTI)

    Center for Human Reliability Studies

    2008-02-01T23:59:59.000Z

    Overview of types of prescription drugs and over-the-counter medications that must be reported in DOE's Human Reliability Program.

  16. A relativistic self-consistent model for studying enhancement of space charge limited field emission due to counter-streaming ions

    SciTech Connect (OSTI)

    Lin, M. C., E-mail: mingchiehlin@gmail.com; Lu, P. S. [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China) [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Chang, P. C. [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China) [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Ragan-Kelley, B. [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States) [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Verboncoeur, J. P. [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States) [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-02-15T23:59:59.000Z

    Recently, field emission has attracted increasing attention despite the practical limitation that field emitters operate below the Child-Langmuir space charge limit. By introducing counter-streaming ion flow to neutralize the electron charge density, the space charge limited field emission (SCLFE) current can be dramatically enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of SCLFE by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a benchmark or comparison for verification of simulation codes, as well as extension to higher dimensions.

  17. Fabrication of silica aerogel with $n$ = 1.08 for $e^+/\\mu ^+$ separation in a threshold Cherenkov counter of the J-PARC TREK/E36 experiment

    E-Print Network [OSTI]

    Tabata, Makoto; Kawai, Hideyuki; Igarashi, Youichi; Imazato, Jun; Shimizu, Suguru; Yamazaki, Hirohito

    2015-01-01T23:59:59.000Z

    This study presents the development of hydrophobic silica aerogel for use as a radiator in threshold-type Cherenkov counters. These counters are to be used for separating positrons and positive muons produced by kaon decay in the J-PARC TREK/E36 experiment. We chose to employ aerogel with a refractive index of 1.08 to identify charged particles with momenta of approximately 240 MeV/$c$, and the radiator block shape was designed with a trapezoidal cross-section to fit the barrel region surrounding the kaon stopping target in the center of the TREK/E36 detector system. Including spares, we obtained 30 crack-free aerogel blocks segmented into two layers, each layer having a thickness of 2 cm and a length of 18 cm, to fill 12 counter modules. Optical measurements showed that the produced aerogel tiles had the required refractive indices and transparency.

  18. Particle separation

    DOE Patents [OSTI]

    Moosmuller, Hans (Reno, NV); Chakrabarty, Rajan K. (Reno, NV); Arnott, W. Patrick (Reno, NV)

    2011-04-26T23:59:59.000Z

    Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

  19. Light nuclei quasiparticle energy shift in hot and dense nuclear matter

    E-Print Network [OSTI]

    G. Röpke

    2008-10-25T23:59:59.000Z

    Nuclei in dense matter are influenced by the medium. In the cluster mean field approximation, an effective Schr\\"odinger equation for the $A$-particle cluster is obtained accounting for the effects of the correlated medium such as self-energy, Pauli blocking and Bose enhancement. Similar to the single-baryon states (free neutrons and protons), the light elements ($2 \\le A \\le 4$, internal quantum state $\

  20. Compressibility of Nuclear Matter from Shell Effects in Nuclei

    E-Print Network [OSTI]

    M. M. Sharma

    1999-04-13T23:59:59.000Z

    The compressibility of nuclear matter has received significant attention in the last decade and a variety of approaches have been employed to extract this fundamental property of matter. Recently, significant differences have emerged between the results of relativistic and non-relativistic calculations of breathing mode giant monopole resonance (GMR). This is due to a lack of understanding of the dynamics of GMR and of its exact relationship to the compression modulus of the infinite nuclear matter. Here, I present an alternative approach based upon nuclear shell effects. The shell effects are known to manifest experimentally in terms of particle-separation energies with an exceedingly high precision. Within the framework of the non-relativistic density-dependent Skyrme theory, it is shown that the compressibility of nuclear matter has a significant influence on shell effects in nuclei. It is shown that 2-neutron separation energies and hence the empirical shell effects can be used to constrain the compressibility of nuclear matter.

  1. Active Galactic Nuclei under the scrutiny of CTA

    E-Print Network [OSTI]

    Sol, H; Boisson, C; de Almeida, U Barres; Biteau, J; Contreras, J -L; Giebels, B; Hassan, T; Inoue, Y; Katarzynski, K; Krawczynski, H; Mirabal, N; Poutanen, J; Rieger, F; Totani, T; Benbow, W; Cerruti, M; Errando, M; Fallon, L; Pino, E de Gouveia Dal; Hinton, J -A; Inoue, S; Lenain, J -P; Neronov, A; Takahashi, K; Takami, H; White, R

    2013-01-01T23:59:59.000Z

    Active Galactic Nuclei (hereafter AGN) produce powerful outflows which offer excellent conditions for efficient particle acceleration in internal and external shocks, turbulence, and magnetic reconnection events. The jets as well as particle accelerating regions close to the supermassive black holes (hereafter SMBH) at the intersection of plasma inflows and outflows, can produce readily detectable very high energy gamma-ray emission. As of now, more than 45 AGN including 41 blazars and 4 radiogalaxies have been detected by the present ground-based gamma-ray telescopes, which represents more than one third of the cosmic sources detected so far in the VHE gamma-ray regime. The future Cherenkov Telescope Array (CTA) should boost the sample of AGN detected in the VHE range by about one order of magnitude, shedding new light on AGN population studies, and AGN classification and unification schemes. CTA will be a unique tool to scrutinize the extreme high-energy tail of accelerated particles in SMBH environments, t...

  2. FB-line neutron multiplicity counter operation manual

    SciTech Connect (OSTI)

    Langner, D.G.; Sweet, M.R.; Salazar, S.D.; Kroncke, K.E.

    1997-12-31T23:59:59.000Z

    This manual describes the design features, performance, and operating characteristics for the FB-Line Neutron Multiplicity counter (FBLNMC). The FBLNMC counts neutron multiplicities to quantitatively assay plutonium in many forms, including impure scrap and waste. Monte Carlo neutronic calculations were used to design the high-efficiency (57%) detector that has 113 {sup 3}He tubes in a high-density polyethylene body. The new derandomizer circuit is included in the design to reduce deadtime. The FBLNMC can be applied to plutonium masses in the range from a few tens of grams to 5 kg; both conventional coincidence counting and multiplicity counting can be used as appropriate. This manual gives the performance data and preliminary calibration parameters for the FBLNMC.

  3. Underground Muon Counters as a Tool for Composition Analyses

    E-Print Network [OSTI]

    A. D. Supanitsky; A. Etchegoyen; G. Medina-Tanco; I. Allekotte; M. Gómez Berisso; M. C. Medina

    2008-10-13T23:59:59.000Z

    The transition energy from galactic to extragalactic cosmic ray sources is still uncertain, but it should be associated either with the region of the spectrum known as the second knee or with the ankle. The baseline design of the Pierre Auger Observatory was optimized for the highest energies. The surface array is fully efficient above $3 \\times 10^{18}$ eV and, even if the hybrid mode can extend this range below $10^{18}$ eV, the second knee and a considerable portion of the wide ankle structure are left outside its operating range. Therefore, in order to encompass these spectral features and gain further insight into the cosmic ray composition variation along the transition region, enhancements to the surface and fluorescence components of the baseline design are being implemented that will lower the full efficiency regime of the Observatory down to $\\sim 10^{17}$ eV. The surface enhancements consist of a graded infilled area of standard Auger water Cherenkov detectors deployed in two triangular grids of 433 m and 750 m of spacing. Each surface station inside this area will have an associated muon counter detector. The fluorescence enhancement, on the other hand, consists of three additional fluorescence telescopes with higher elevation angle ($30^\\circ-58^\\circ$) than the ones in operation at present. The aim of this paper is threefold. We study the effect of the segmentation of the muon counters and find an analytical expression to correct for the under counting due to muon pile-up. We also present a detailed method to reconstruct the muon lateral distribution function for the 750 m spacing array. Finally, we study the mass discrimination potential of a new parameter, the number of muons at 600 m from the shower axis, obtained by fitting the muon data with the above mentioned reconstruction method.

  4. Single-ended counter-rotating radial turbine for space application

    DOE Patents [OSTI]

    Coomes, E.P.; Wilson, D.G.; Webb, B.J.; McCabe, S.J.

    1987-05-13T23:59:59.000Z

    A single-ended turbine with counter-rotating blades operating with sodium as the working fluid. The single-ended, counter-rotating feature of the turbine results in zero torque application to a space platform. Thus, maneuvering of the platform is not adversely affected by the turbine. 4 figs.

  5. Three-dimensional MHD simulations of counter-helicity spheromak merging in the Swarthmore Spheromak Experiment

    E-Print Network [OSTI]

    Brown, Michael R.

    Three-dimensional MHD simulations of counter-helicity spheromak merging in the Swarthmore Spheromak September 2011) Recent counter-helicity spheromak merging experiments in the Swarthmore Spheromak Experiment spheromak- and FRC-like characteristics. In this paper, the SSX merging process is studied in detail using

  6. Entrance channel dependence in compound nuclear reactions with loosely bound nuclei

    E-Print Network [OSTI]

    S. Adhikari; C. Samanta; C. Basu; S. Ray; A. Chattaerjee; S. Kailas

    2005-05-13T23:59:59.000Z

    The measurement of light charged particles evaporated from the reaction 6,7Li+6Li has been carried out at extreme backward angle in the energy range 14 - 20 MeV. Calculations from the code ALICE91 show that the symmetry of the target-projectile combination and the choice of level density parameter play important roles in explaining the evaporation spectra for these light particle systems. In above barrier energy region the fusion cross-section is not suppressed for these loosely bound nuclei.

  7. Additivity of effective quadrupole moments and angular momentum alignments in the A~130 nuclei

    E-Print Network [OSTI]

    M. Matev; A. V. Afanasjev; J. Dobaczewski; G. A. Lalazissis; W. Nazarewicz

    2007-07-30T23:59:59.000Z

    The additivity principle of the extreme shell model stipulates that an average value of a one-body operator be equal to the sum of the core contribution and effective contributions of valence (particle or hole) nucleons. For quadrupole moment and angular momentum operators, we test this principle for highly and superdeformed rotational bands in the A~130 nuclei. Calculations are done in the self-consistent cranked non-relativistic Hartree-Fock and relativistic Hartree mean-field approaches. Results indicate that the additivity principle is a valid concept that justifies the use of an extreme single-particle model in an unpaired regime typical of high angular momenta.

  8. Cell diameter measurements obtained with a handheld cell counter could be used as a surrogate marker of G2/M arrest and apoptosis in colon cancer cell lines exposed to SN-38

    SciTech Connect (OSTI)

    Tahara, Makiko [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan) [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan); Department of Gastrointestinal Surgery, Jichi Medical University, Shimotsuke, Tochigi (Japan); Inoue, Takeshi [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan)] [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan); Miyakura, Yasuyuki; Horie, Hisanaga; Yasuda, Yoshikazu [Department of Gastrointestinal Surgery, Jichi Medical University, Shimotsuke, Tochigi (Japan)] [Department of Gastrointestinal Surgery, Jichi Medical University, Shimotsuke, Tochigi (Japan); Fujii, Hirofumi [Division of Clinical Oncology, Jichi Medical University, Shimotsuke, Tochigi (Japan)] [Division of Clinical Oncology, Jichi Medical University, Shimotsuke, Tochigi (Japan); Kotake, Kenjiro [Department of Surgery, Tochigi Cancer Center, Utsunomiya, Tochigi (Japan)] [Department of Surgery, Tochigi Cancer Center, Utsunomiya, Tochigi (Japan); Sugano, Kokichi, E-mail: ksugano@tcc.pref.tochigi.lg.jp [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan)] [Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, Utsunomiya, Tochigi (Japan)

    2013-05-17T23:59:59.000Z

    Highlights: •Chemo-sensitivity to SN-38 was assayed by the automated cell counter. •Colon cancer cell line, HCT116 cells were more sensitive to SN-38 than HT29 cells. •Increase of cell size reflects G2/M arrest. •Appearance of small particles indicates cell apoptosis. -- Abstract: In vitro assessment of chemosensitivity are important for experiments evaluating cancer therapies. The Scepter 2.0 cell counter, an automated handheld device based on the Coulter principle of impedance-based particle detection, enables the accurate discrimination of cell populations according to cell size and volume. In this study, the effects of SN-38, the active metabolite of irinotecan, on the colon cancer cell lines HCT116 and HT29 were evaluated using this device. The cell count data obtained with the Scepter counter were compared with those obtained with the {sup 3}H-thymidine uptake assay, which has been used to measure cell proliferation in many previous studies. In addition, we examined whether the changes in the size distributions of these cells reflected alterations in the frequency of cell cycle arrest and/or apoptosis induced by SN-38 treatment. In our experiments using the Scepter 2.0 cell counter, the cell counts were demonstrated to be accurate and reproducible measure and alterations of cell diameter reflected G2/M cell cycle arrest and apoptosis. Our data show that easy-to-use cell counting tools can be utilized to evaluate the cell-killing effects of novel treatments on cancer cells in vitro.

  9. Is Fusion Inhibited for Weakly Bound Nuclei?

    SciTech Connect (OSTI)

    Takahashi, J.; Munhoz, M.; Szanto, E.M.; Carlin, N.; Added, N.; Suaide, A.A.; de Moura, M.M.; Liguori Neto, R.; Szanto de Toledo, A. [Universidade de Sao Paulo, Institute de Fisica, Departamento de Fisica Nuclear, Caixa Postal 66318, 05389-970 Sao Paulo, Sao Paulo, (Brasil)] [Universidade de Sao Paulo, Institute de Fisica, Departamento de Fisica Nuclear, Caixa Postal 66318, 05389-970 Sao Paulo, Sao Paulo, (Brasil); Canto, L.F. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ, (Brasil)] [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970 Rio de Janeiro, RJ, (Brasil)

    1997-01-01T23:59:59.000Z

    Complete fusion of light radioactive nuclei is predicted to be hindered at near-barrier energies. This feature is investigated in the case of the least bound stable nuclei. Evaporation residues resulting from the {sup 6,7}Li+{sup 9}Be and {sup 6,7}Li+{sup 12}C fusion reactions have been measured in order to study common features in reactions involving light weakly bound nuclei. The experimental excitation functions revealed that the fusion cross section is significantly smaller than the total reaction cross section and also smaller than the fusion cross section expected from the available systematics. A clear correlation between the fusion probability and nucleon (cluster) separation energy has been established.The results suggest that the breakup process has a strong influence on the hindrance of the fusion cross section. {copyright} {ital 1996} {ital The American Physical Society}

  10. Performance confirmation of the Belle II imaging Time Of Propogation (iTOP) prototype counter

    SciTech Connect (OSTI)

    Schwartz, Alan; Liu, Yang; Belhorn, Matt; /Cincinnati U.; Browder, Thomas; Varner, Gary; Andrew, Matt; Rosen, Marc; Barrett, Matthew; Nishimura, Kurtis; Anderson, Eric /Hawaii U.; Iijima, Toru; /Nagoya U. /PNL, Richland

    2011-10-17T23:59:59.000Z

    The Bell Detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider performed extremely well, logging an integrated luminosity an order of magnitude higher than the design baseline. With this inverse attobarn of integrated luminosity, time-dependent CP-violation inn the 3rd generation beauty quarks was firmly established, and is now a precision measurement. Going beyond this to explore if the Kobayashi-Maskawa mechanism is the only contributor to quark-mixing, and to interrogate the flavor sector for non-standard model enhancements, requires a detector and accelerator capable of topping this world-record luminosity by more than an order of magnitude. The Belle II detector at the upgraded Super-KEKB accelerator has been designed to meet this highly ambitious goal of operating at a luminosity approaching 10{sup 36} cm{sup -2} s{sup -1}. Such higher event rates and backgrounds require upgrade of essentially all detector subsystems, as well as their readout. Comparing the Belle composite (threshold Aerogel + Time of Flight) particle identification (PID) system with the DIRC employed by BaBar, quartz radiator internal Cherenkov photon detection proved to have higher kaon efficiency and lower pion fake rates. However, because the detector structure and CsI calorimeter will be retained, an improved barrel PID must fit within a very narrow envelope, as indicated in Figure 1. To effectively utilize this space, a more compact detector concept based on the same quartz radiators, but primarily using photon arrival time was proposed. This Time Of Propagation (TOP) counter was studied in a number of earlier prototype tests. Key to the necessary 10's of picosecond single-photon timing has been the development of the so-called SL-10 Micro-Channel Plate Photo-Multiplier Tube (MCP-PMT), which has demonstrated sub-40 ps single photon Transit Time Spread TTS. Further simulation study of this detector concept indicated that a focusing mirror in the forward direction, as well as a modest image expansion volume and more highly pixelated image plane improve the theoretical detector performance, since timing alone is limited by chromatic dispersion of the Cherenkov photons. This imaging-TOP (or iTOP) counter is the basis of Belle II barrel PID upgrade. However, a number of critical performance parameters must be demonstrated prior to releasing this prototype design for production manufacture.

  11. Polarized structure functions of nucleons and nuclei

    SciTech Connect (OSTI)

    W. Bentz; I. C. Cloet; T. Ito; A. W. Thomas; K. Yazaki

    2007-09-16T23:59:59.000Z

    We determine the quark distributions and structure functions for both unpolarized and polarized DIS of leptons on nucleons and nuclei. The scalar and vector mean fields in the nucleus modify the motion of the quarks inside the nucleons. By taking into account this medium modification, we are able to reproduce the experimental data on the unpolarized EMC effect, and to make predictions for the polarized EMC effect. We discuss examples of nuclei where the polarized EMC effect could be measured. We finally present an extension of our model to describe fragmentation functions.

  12. Illuminations Subtraction games worksheet Lesson 2, Games 1. Consider the game G1 which starts with one pile of 20 counters.

    E-Print Network [OSTI]

    Reiter, Harold

    with one pile of 20 counters. The rules allow a player to take 1, 3, or 5 counters on each turn. The player starts with one pile of 20 counters. The rules allow a player to take 1, 2, or 5 counters on each turn G3 which starts with one pile of 20 counters. The rules allow a player to take 1, 2, or 6 counters

  13. A new equation of state with light nuclei and their weak interactions in core-collapse supernova simulations

    SciTech Connect (OSTI)

    Furusawa, Shun; Yamada, Shoichi [Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan); Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 (Japan); Sumiyoshi, Kohsuke [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Suzuki, Hideyuki [Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan)

    2014-05-02T23:59:59.000Z

    We perform numerical experiments to investigate the influence of inelastic neutrino reactions with light nuclei on the standing accretion shock instability. The time evolutions of shock waves are calculated with a simple light-bulb approximation for the neutrino transport and a multi-nuclei equation of state. The neutrino absorptions and inelastic interactions with deuterons, tritons, helions and alpha particles are taken into account in the hydrodynamical simulations in addition to the ordinary charged-current interactions with nucleons. Axial symmetry is assumed but no equatorial symmetry is imposed. We show that the heating rates of deuterons reach as high as ? 10% of those of nucleons around the bottom of the gain region. On the other hands, alpha particles heat the matter near the shock wave, which is important when the shock wave expands and density and temperature of matter become low. It is also found that the models with heating by light nuclei have different evolutions from those without it in non-linear evolution phase. The matter in the gain region has various densities and temperatures and there appear regions that are locally rich in deuterons and alpha particles. These results indicate that the inelastic reactions of light nuclei, especially deuterons, should be incorporated in the simulations of core-collapse supernovae.

  14. amphoter target nuclei: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2001-12-31 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

  15. Effects of Beta-Decays of Excited-State Nuclei on the Astrophysical r-Process

    E-Print Network [OSTI]

    M. A. Famiano; R. N. Boyd; T. Kajino; K. Otsuki; M. Terasawa; G. J. Mathews

    2008-08-07T23:59:59.000Z

    A rudimentary calculation is employed to evaluate the possible effects of beta- decays of excited-state nuclei on the astrophysical r-process. Single-particle levels calculated with the FRDM are adapted to the calculation of beta-decay rates of these excited-state nuclei. Quantum numbers are determined based on proximity to Nilson model levels. The resulting rates are used in an r-process network calculation in which a supernova hot-bubble model is coupled to an extensive network calculation including all nuclei between the valley of stability and the neutron drip line and with masses ABeta-decay rates are included as functional forms of the environmental temperature. While the decay rate model used is simple and phenomenological, it is consistent across all 3700 nuclei involved in the r-process network calculation. This represents an approximate first estimate to gauge the possible effects of excited-state beta-decays on r-process freeze-out abundances.

  16. Shell effects in hot nuclei and their influence on nuclear composition in supernova matter

    SciTech Connect (OSTI)

    Nishimura, Suguru [Department of Pure and Applied Physics, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan); Takano, Masatoshi [Department of Pure and Applied Physics, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555, Japan and Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan)

    2014-05-02T23:59:59.000Z

    We calculate nuclear composition in supernova (SN) matter explicitly taking into account the temperature dependence of nuclear shell effects. The abundance of nuclei in SN matter is important in the dynamics of core-collapse supernovae and, in recently constructed equations of state (EOS) for SN matter, the composition of nuclei are calculated assuming nuclear statistical equilibrium wherein the nuclear internal free energies govern the composition. However, in these EOS, thermal effects on the shell energy are not explicitly taken into account. To address this shortfall, we calculate herein the shell energies of hot nuclei and examine their influence on the composition of SN matter. Following a simplified macroscopic-microscopic approach, we first calculate single-particle (SP) energies by using a spherical Woods-Saxon potential. Then we extract shell energies at finite temperatures using Strutinsky method with the Fermi distribution as the average occupation probability of the SP levels. The results show that at relatively low temperatures, shell effects are still important and magic nuclei are abundant. However, at temperatures above approximately 2 MeV, shell effects are almost negligible, and the mass fractions with shell energies including the thermal effect are close to those obtained from a simple liquid drop model at finite temperatures.

  17. CHICO2 - A pixelated parallel-plate avalanche counter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for the charged-particle detection. The design and fabrication work were carried out at University of Rochester under NSF funding. A total of 26 GammasphereCHICO experiments...

  18. Semi-microscopic description of the double backbending in some deformed even-even rare earth nuclei

    E-Print Network [OSTI]

    R. Budaca; A. A. Raduta

    2013-01-25T23:59:59.000Z

    A semi-microscopic model to study the neutron and proton induced backbending phenomena in some deformed even-even nuclei from the rare earth region, is proposed. The space of particle-core states is defined by the angular momentum projection of a quadrupole deformed product state. The backbending phenomena are described by mixing four rotational bands, defined by a set of angular momentum projected states, and a model Hamiltonian describing a set of paired particles moving in a deformed mean field and interacting with a phenomenological deformed core. The ground band corresponds to the configuration where all particles are paired while the other rotational bands are built on one neutron or/and one proton broken pair. Four rare earth even-even nuclei which present the second anomaly in the observed moments of inertia are successfully treated within the proposed model.

  19. Thermodynamics of nuclei in thermal contact

    E-Print Network [OSTI]

    Karl-Heinz Schmidt; Beatriz Jurado

    2010-10-05T23:59:59.000Z

    The behaviour of a di-nuclear system in the regime of strong pairing correlations is studied with the methods of statistical mechanics. It is shown that the thermal averaging is strong enough to assure the application of thermodynamical methods to the energy exchange between the two nuclei in contact. In particular, thermal averaging justifies the definition of a nuclear temperature.

  20. Real-time multi-mode neutron multiplicity counter

    DOE Patents [OSTI]

    Rowland, Mark S; Alvarez, Raymond A

    2013-02-26T23:59:59.000Z

    Embodiments are directed to a digital data acquisition method that collects data regarding nuclear fission at high rates and performs real-time preprocessing of large volumes of data into directly useable forms for use in a system that performs non-destructive assaying of nuclear material and assemblies for mass and multiplication of special nuclear material (SNM). Pulses from a multi-detector array are fed in parallel to individual inputs that are tied to individual bits in a digital word. Data is collected by loading a word at the individual bit level in parallel, to reduce the latency associated with current shift-register systems. The word is read at regular intervals, all bits simultaneously, with no manipulation. The word is passed to a number of storage locations for subsequent processing, thereby removing the front-end problem of pulse pileup. The word is used simultaneously in several internal processing schemes that assemble the data in a number of more directly useable forms. The detector includes a multi-mode counter that executes a number of different count algorithms in parallel to determine different attributes of the count data.

  1. Measuring FLOPS Using Hardware Performance Counter Technologies on LC systems

    SciTech Connect (OSTI)

    Ahn, D H

    2008-09-05T23:59:59.000Z

    FLOPS (FLoating-point Operations Per Second) is a commonly used performance metric for scientific programs that rely heavily on floating-point (FP) calculations. The metric is based on the number of FP operations rather than instructions, thereby facilitating a fair comparison between different machines. A well-known use of this metric is the LINPACK benchmark that is used to generate the Top500 list. It measures how fast a computer solves a dense N by N system of linear equations Ax=b, which requires a known number of FP operations, and reports the result in millions of FP operations per second (MFLOPS). While running a benchmark with known FP workloads can provide insightful information about the efficiency of a machine's FP pipelines in relation to other machines, measuring FLOPS of an arbitrary scientific application in a platform-independent manner is nontrivial. The goal of this paper is twofold. First, we explore the FP microarchitectures of key processors that are underpinning the LC machines. Second, we present the hardware performance monitoring counter-based measurement techniques that a user can use to get the native FLOPS of his or her program, which are practical solutions readily available on LC platforms. By nature, however, these native FLOPS metrics are not directly comparable across different machines mainly because FP operations are not consistent across microarchitectures. Thus, the first goal of this paper represents the base reference by which a user can interpret the measured FLOPS more judiciously.

  2. Improved Technology To Prevent Nuclear Proliferation And Counter Nuclear Terrorism

    SciTech Connect (OSTI)

    Richardson, J; Yuldashev, B; Labov, S; Knapp, R

    2006-06-12T23:59:59.000Z

    As the world moves into the 21st century, the possibility of greater reliance on nuclear energy will impose additional technical requirements to prevent proliferation. In addition to proliferation resistant reactors, a careful examination of the various possible fuel cycles from cradle to grave will provide additional technical and nonproliferation challenges in the areas of conversion, enrichment, transportation, recycling and waste disposal. Radiation detection technology and information management have a prominent role in any future global regime for nonproliferation. As nuclear energy and hence nuclear materials become an increasingly global phenomenon, using local technologies and capabilities facilitate incorporation of enhanced monitoring and detection on the regional level. Radiation detection technologies are an important tool in the prevention of proliferation and countering radiological/nuclear terrorism. A variety of new developments have enabled enhanced performance in terms of energy resolution, spatial resolution, passive detection, predictive modeling and simulation, active interrogation, and ease of operation and deployment in the field. For example, various gamma ray imaging approaches are being explored to combine spatial resolution with background suppression in order to enhance sensitivity many-fold at reasonable standoff distances and acquisition times. New materials and approaches are being developed in order to provide adequate energy resolution in field use without the necessity for liquid nitrogen. Different detection algorithms enable fissile materials to be distinguished from other radioisotopes.

  3. Counter flow cooling drier with integrated heat recovery

    DOE Patents [OSTI]

    Shivvers, Steve D. (Prole, IA)

    2009-08-18T23:59:59.000Z

    A drier apparatus for removing water or other liquids from various materials includes a mixer, drying chamber, separator and regenerator and a method for use of the apparatus. The material to be dried is mixed with a heated media to form a mixture which then passes through the chamber. While passing through the chamber, a comparatively cool fluid is passed counter current through the mixture so that the mixture becomes cooler and drier and the fluid becomes hotter and more saturated with moisture. The mixture is then separated into drier material and media. The media is transferred to the regenerator and heated therein by the hot fluid from the chamber and supplemental heat is supplied to bring the media to a preselected temperature for mixing with the incoming material to be dried. In a closed loop embodiment of the apparatus, the fluid is also recycled from the regenerator to the chamber and a chiller is utilized to reduce the temperature of the fluid to a preselected temperature and dew point temperature.

  4. Phase-kicked control of counter-rotating interactions in the quantum Rabi model

    E-Print Network [OSTI]

    Jin-Feng Huang; C. K. Law

    2014-07-17T23:59:59.000Z

    We present an interaction scheme to control counter-rotating terms in the quantum Rabi model. We show that by applying a sequence of $\\pi/2$ phase kicks to a two-level atom and a single mode quantized field, the natural dynamics of the Rabi model can be interrupted in a way that counter-rotating transitions can be significantly enhanced. This is achieved by a suitable timing of the phase kicks determined by a phase matching condition. If the time between successive kicks is sufficiently short, our scheme is turned into a dynamical decoupling problem in which the effects of counter-rotating terms can be strongly suppressed under ultrastrong coupling.

  5. Photon parton distributions in nuclei and the EMC effect

    SciTech Connect (OSTI)

    Frankfurt, L. [School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Strikman, M. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States)

    2010-12-15T23:59:59.000Z

    Photons, as well as quarks and gluons, are constituents of the infinite momentum frame (IMF) wave function of an energetic particle. They are mostly equivalent photons whose amplitude follows from the Lorentz transformation of the particle rest frame Coulomb field into the IMF and from the conservation of the electromagnetic current. We evaluate in a model independent way the dominant photon contribution {proportional_to}{alpha}{sub em}(Z{sup 2}/A{sup 4/3})ln(1/R{sub A}m{sub N}x) to the nuclear structure functions as well as the term {proportional_to}{alpha}{sub em}Z/A. In addition we show that the definition of x consistent with the exact kinematics of eA scattering (with exact sum rules) works in the same direction as the nucleus field of equivalent photons. Combined, these effects account for the bulk of the hadronic European Muon Collaboration (EMC) effect for x{<=}0.5 where Fermi motion effects are small. In particular, for these x the hadronic mechanism contribution to the EMC effect does not exceed {approx}3% for all nuclei. Also, the A dependence of the hadronic mechanism of the EMC effect for x>0.5 is significantly modified.

  6. Photon parton distributions in nuclei and the EMC effect

    SciTech Connect (OSTI)

    Leonid Frankfurt, Mark Strikman

    2010-12-01T23:59:59.000Z

    Photons as well as quarks and gluons are constituents of the infinite momentum frame (IMF) wave function of an energetic particle. They are mostly equivalent photons whose amplitude follows from the Lorentz transformation of the particle rest frame Coulomb field into the IMF and from the conservation of the electromagnetic current. We evaluate in a model independent way the dominant photon contribution \\propto \\alpha_{em}(Z^2/A^{4/3})\\ln(1/R_{A}m_{N}x) to the nuclear structure functions as well as the term \\propto \\alpha_{em}Z/A. In addition we show that the definition of x consistent with the exact kinematics of eA scattering (with exact sum rules) works in the same direction as the nucleus field of equivalent photons. Combined, these effects account for the bulk of the EMC effect for x\\le 0.5 where Fermi motion effects are small. In particular for these x the hadronic mechanism contribution to the EMC effect does not exceed \\sim 3% for all nuclei. Also the A-dependence of the hadronic mechanism of the EMC effect for x > 0.5 is significantly modified.

  7. Photon parton distributions in nuclei and the EMC effect

    E-Print Network [OSTI]

    Leonid Frankfurt; Mark Strikman

    2010-12-15T23:59:59.000Z

    Photons as well as quarks and gluons are constituents of the infinite momentum frame (IMF) wave function of an energetic particle. They are mostly equivalent photons whose amplitude follows from the Lorentz transformation of the particle rest frame Coulomb field into the IMF and from the conservation of the electromagnetic current. We evaluate in a model independent way the dominant photon contribution \\propto \\alpha_{em}(Z^2/A^{4/3})\\ln(1/R_{A}m_{N}x) to the nuclear structure functions as well as the term \\propto \\alpha_{em}Z/A. In addition we show that the definition of x consistent with the exact kinematics of eA scattering (with exact sum rules) works in the same direction as the nucleus field of equivalent photons. Combined, these effects account for the bulk of the EMC effect for x\\le 0.5 where Fermi motion effects are small. In particular for these x the hadronic mechanism contribution to the EMC effect does not exceed \\sim 3% for all nuclei. Also the A-dependence of the hadronic mechanism of the EMC effect for x > 0.5 is significantly modified.

  8. Collective and non-collective structures in nuclei of mass region A ? 125

    SciTech Connect (OSTI)

    Singh, A. K. [Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Collaboration: INGA Collaboration; Gammasphere Collaboration

    2014-08-14T23:59:59.000Z

    Generation of angular momentum in nuclei is a key question in nuclear structure studies. In single particle model, it is due to alignment of spin of individual nucleon available in the valence space, whereas coherent motion of nucleons are assumed in the collective model. The nuclei near the closed shell at Z = 50 with mass number A ? 120-125 represent ideal cases to explore the interplay between these competing mechanisms and the transition from non-collective to collective behavior or vice versa. Recent spectroscopic studies of nuclei in this region reveal several non-collective maximally aligned states representing the first kind of excitation mechanism, where 8-12 particles above the {sup 114}Sn align their spins to generate these states. Deformed rotational bands feeding the non-collective states in the spin range I=20-25 and excitation energies around 10 MeV have also been observed. Structure of the collective and non-collective states are discussed in the framework of Cranked-Nilsson-Strutinsky model.

  9. Design and operation of a counter-rotating aspirated compressor blowdown test facility

    E-Print Network [OSTI]

    Parker, David V. (David Vickery)

    2005-01-01T23:59:59.000Z

    A unique counter-rotating aspirated compressor was tested in a blowdown facility at the Gas Turbine Laboratory at MIT. The facility expanded on experience from previous blowdown turbine and blowdown compressor experiments. ...

  10. Materials and Textile Architecture Analyses for Mechanical Counter-Pressure Space Suits using Active Materials

    E-Print Network [OSTI]

    Buechley, Leah

    Mechanical counter-pressure (MCP) space suits have the potential to improve the mobility of astronauts as they conduct planetary exploration activities. MCP suits differ from traditional gas-pressurized space suits by ...

  11. Assessment and preliminary model development of shape memory polymers mechanical counter pressure space suits

    E-Print Network [OSTI]

    Wee, Brian (Brian J.)

    2013-01-01T23:59:59.000Z

    This thesis seeks to assess the viability of a space qualified shape memory polymer (SMP) mechanical counter pressure (MCP) suit. A key development objective identified by the International Space Exploration Coordination ...

  12. Calibration methodology for proportional counters applied to yield measurements of a neutron burst

    SciTech Connect (OSTI)

    Tarifeńo-Saldivia, Ariel, E-mail: atarifeno@cchen.cl, E-mail: atarisal@gmail.com; Pavez, Cristian; Soto, Leopoldo [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile) [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Center for Research and Applications in Plasma Physics and Pulsed Power, P4, Santiago (Chile); Departamento de Ciencias Fisicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Republica 220, Santiago (Chile); Mayer, Roberto E. [Instituto Balseiro and Centro Atómico Bariloche, Comisión Nacional de Energía Atómica and Universidad Nacional de Cuyo, San Carlos de Bariloche R8402AGP (Argentina)] [Instituto Balseiro and Centro Atómico Bariloche, Comisión Nacional de Energía Atómica and Universidad Nacional de Cuyo, San Carlos de Bariloche R8402AGP (Argentina)

    2014-01-15T23:59:59.000Z

    This paper introduces a methodology for the yield measurement of a neutron burst using neutron proportional counters. This methodology is to be applied when single neutron events cannot be resolved in time by nuclear standard electronics, or when a continuous current cannot be measured at the output of the counter. The methodology is based on the calibration of the counter in pulse mode, and the use of a statistical model to estimate the number of detected events from the accumulated charge resulting from the detection of the burst of neutrons. The model is developed and presented in full detail. For the measurement of fast neutron yields generated from plasma focus experiments using a moderated proportional counter, the implementation of the methodology is herein discussed. An experimental verification of the accuracy of the methodology is presented. An improvement of more than one order of magnitude in the accuracy of the detection system is obtained by using this methodology with respect to previous calibration methods.

  13. Riding Waves of Dissent: Counter-Imperial Impulses in the Age of Fuller and Melville

    E-Print Network [OSTI]

    Lawrence, Nicholas M.

    2010-10-12T23:59:59.000Z

    This dissertation examines the interplay between antebellum frontier literature and the counter-imperial impulses that impelled the era's political, cultural, and literary developments. Focusing on selected works by James Fenimore Cooper, Margaret...

  14. Study of dissipative dynamics in fission of hot nuclei using Langevin equation

    E-Print Network [OSTI]

    Chaudhuri, G

    2004-01-01T23:59:59.000Z

    The fission of highly excited compound nuclei formed in heavy ion induced fusion reactions has emerged as a topic of considerable interest in the recent years. Dissipative dynamical models based on the Langevin equation were developed and were applied successfully for fission dynamics of highly excited heavy nuclei. However, Wall Friction(WF), the standard version of nuclear friction when incorporated in the Langevin dynamical model was not able to reproduce simultaneously experimental data for both prescission neutron multiplicity and fission probability. Consequently, an empirical reduction in the strength of the wall friction was found necessary to reproduce the experimental numbers by many workers. Interestingly, a modification of the wall friction was proposed recently where the reduction was achieved microscopically. This modified version is known as the chaos weighted wall friction(CWWF) which takes into account non-integrability of single particle motion. The work in my thesis aims at using this stron...

  15. Ab-initio Gorkov-Green's function calculations of open-shell nuclei

    E-Print Network [OSTI]

    V. Soma; C. Barbieri; T. Duguet

    2012-08-13T23:59:59.000Z

    We present results from a new ab-initio method that uses the self-consistent Gorkov Green's function theory to address truly open-shell systems. The formalism has been recently worked out up to second order and is implemented here in nuclei for the first time on the basis of realistic nuclear forces. We find good convergence of the results with respect to the basis size in Ca44 and Ni74 and discuss quantities of experimental interest including ground-state energies, pairing gaps and particle addition/removal spectroscopy. These results demonstrate that the Gorkov method is a valid alternative to multireference approaches for tackling degenerate or near degenerate quantum systems. In particular, it increases the number of mid-mass nuclei accessible in an ab-initio fashion from a few tens to a few hundreds.

  16. Mass dependence of short-range correlations in nuclei and the EMC effect

    E-Print Network [OSTI]

    Vanhalst, Maarten; Cosyn, Wim

    2012-01-01T23:59:59.000Z

    An approximate method to quantify the mass dependence of the number of two-nucleon (2N) short-range correlations (SRC) in nuclei is suggested. The proposed method relies on the concept of the "local nuclear character" of the SRC. We quantify the SRC and its mass dependence by computing the number of independent-particle model (IPM) nucleon pairs in a zero relative orbital momentum state. We find that the relative probability per nucleon for 2N SRC follows a power law as a function of the mass number $A$. The predictions are connected to measurements which provide access to the mass dependence of SRC. First, the ratio of the inclusive inelastic electron scattering cross sections of nuclei to $^{2}$H at large values of the Bjorken variable. Second, the EMC effect, for which we find a linear relationship between its magnitude and the predicted number of SRC-prone pairs.

  17. Mass dependence of short-range correlations in nuclei and the EMC effect

    E-Print Network [OSTI]

    Maarten Vanhalst; Jan Ryckebusch; Wim Cosyn

    2012-10-23T23:59:59.000Z

    An approximate method to quantify the mass dependence of the number of two-nucleon (2N) short-range correlations (SRC) in nuclei is suggested. The proposed method relies on the concept of the "local nuclear character" of the SRC. We quantify the SRC and its mass dependence by computing the number of independent-particle model (IPM) nucleon pairs in a zero relative orbital momentum state. We find that the relative probability per nucleon for 2N SRC follows a power law as a function of the mass number $A$. The predictions are connected to measurements which provide access to the mass dependence of SRC. First, the ratio of the inclusive inelastic electron scattering cross sections of nuclei to $^{2}$H at large values of the Bjorken variable. Second, the EMC effect, for which we find a linear relationship between its magnitude and the predicted number of SRC-prone pairs.

  18. Lyapunov exponents of heavy particles in turbulence

    E-Print Network [OSTI]

    Jeremie Bec; Luca Biferale; Guido Boffetta; Massimo Cencini; Stefano Musacchio; Federico Toschi

    2006-06-08T23:59:59.000Z

    Lyapunov exponents of heavy particles and tracers advected by homogeneous and isotropic turbulent flows are investigated by means of direct numerical simulations. For large values of the Stokes number, the main effect of inertia is to reduce the chaoticity with respect to fluid tracers. Conversely, for small inertia, a counter-intuitive increase of the first Lyapunov exponent is observed. The flow intermittency is found to induce a Reynolds number dependency for the statistics of the finite time Lyapunov exponents of tracers. Such intermittency effects are found to persist at increasing inertia.

  19. Coulter counter determination of bacterial growth and cellular size change following ??Co gamma irradiation

    E-Print Network [OSTI]

    Gaston, Gary W

    1976-01-01T23:59:59.000Z

    COULTER COUNTER DETERMINATION OF BACTERIAL GROWTH AND CELLULAR SIZE CHANGE FOLLOWING Co GAMMA IRRADIATION A Thesis by GARY W. GASTON Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December 1976 Ma)or Subject: Biophysics COULTER COUNTER DETERMINATION OF BACTERIAL GROWTH AND CELLULAR SIZE CHANGE FOLLOWING Co GAMMA IRRADIATION A Thesis by GARY W. GASTON APPROVED as to style and content by: ead...

  20. Coulter counter determination of bacterial growth and cellular size change following ??Co gamma irradiation 

    E-Print Network [OSTI]

    Gaston, Gary W

    1976-01-01T23:59:59.000Z

    COULTER COUNTER DETERMINATION OF BACTERIAL GROWTH AND CELLULAR SIZE CHANGE FOLLOWING Co GAMMA IRRADIATION A Thesis by GARY W. GASTON Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December 1976 Ma)or Subject: Biophysics COULTER COUNTER DETERMINATION OF BACTERIAL GROWTH AND CELLULAR SIZE CHANGE FOLLOWING Co GAMMA IRRADIATION A Thesis by GARY W. GASTON APPROVED as to style and content by: ead...

  1. Plutonium Measurements with a Fast-Neutron Multiplicity Counter for Nuclear Safeguards Applications

    SciTech Connect (OSTI)

    Jennifer L. Dolan; Marek Flaska; Alexis Poitrasson-Riviere; Andreas Enqvist; Paolo Peerani; David L. Chichester; Sara A. Pozzi

    2014-11-01T23:59:59.000Z

    Measurements were performed at the Joint Research Centre in Ispra, Italy to field test a fast-neutron multiplicity counter developed at the University of Michigan. The measurements allowed the illustration of the system’s photon discrimination abilities, efficiency when measuring neutron multiplicity, ability to characterize 240Pueff mass, and performance relative to a currently deployed neutron coincidence counter. This work is motivated by the need to replace and improve upon 3He neutron detection systems for nuclear safeguards applications.

  2. Neutron shell structure and deformation in neutron-drip-line nuclei

    E-Print Network [OSTI]

    Ikuko Hamamoto

    2012-06-18T23:59:59.000Z

    Neutron shell-structure and the resulting possible deformation in the neighborhood of neutron-drip-line nuclei are systematically discussed, based on both bound and resonant neutron one-particle energies obtained from spherical and deformed Woods-Saxon potentials. Due to the unique behavior of weakly-bound and resonant neutron one-particle levels with smaller orbital angular-momenta $\\ell$, a systematic change of the shell structure and thereby the change of neutron magic-numbers are pointed out, compared with those of stable nuclei expected from the conventional j-j shell-model. For spherical shape with the operator of the spin-orbit potential conventionally used, the $\\ell_{j}$ levels belonging to a given oscillator major shell with parallel spin- and orbital-angular-momenta tend to gather together in the energetically lower half of the major shell, while those levels with anti-parallel spin- and orbital-angular-momenta gather in the upper half. The tendency leads to a unique shell structure and possible deformation when neutrons start to occupy the orbits in the lower half of the major shell. Among others, the neutron magic-number N=28 disappears and N=50 may disappear, while the magic number N=82 may presumably survive due to the large $\\ell =5$ spin-orbit splitting for the $1h_{11/2}$ orbit. On the other hand, an appreciable amount of energy gap may appear at N=16 and 40 for spherical shape, while neutron-drip-line nuclei in the region of neutron number above N=20, 40 and 82, namely N $\\approx$ 21-28, N $\\approx$ 41-54, and N $\\approx$ 83-90, may be quadrupole-deformed though the possible deformation depends also on the proton number of respective nuclei.

  3. Study of dissipative dynamics in fission of hot nuclei using Langevin equation

    E-Print Network [OSTI]

    Gargi Chaudhuri

    2004-11-01T23:59:59.000Z

    The fission of highly excited compound nuclei formed in heavy ion induced fusion reactions has emerged as a topic of considerable interest in the recent years. Dissipative dynamical models based on the Langevin equation were developed and were applied successfully for fission dynamics of highly excited heavy nuclei. However, Wall Friction(WF), the standard version of nuclear friction when incorporated in the Langevin dynamical model was not able to reproduce simultaneously experimental data for both prescission neutron multiplicity and fission probability. Consequently, an empirical reduction in the strength of the wall friction was found necessary to reproduce the experimental numbers by many workers. Interestingly, a modification of the wall friction was proposed recently where the reduction was achieved microscopically. This modified version is known as the chaos weighted wall friction(CWWF) which takes into account non-integrability of single particle motion. The work in my thesis aims at using this strongly shape dependent version of friction (CWWF) in the Langevin dynamical model coupled with particle and gamma evaporation in order to verify to what extent it can account for the experimental data of fission of hot nuclei. The experimental data includes excitation functions of prescission neutron multiplicity, fission probability as well as evaporation residue cross-section of a number of nuclei. The importance of transients in nuclear fission is also discussed. The present endeavour is an effort to obtain a clear physical picture of nuclear dissipation which in turn will help in solving many open problems related to collective motion, and in particular, nuclear fission.

  4. Silicate absorption in heavily obscured galaxy nuclei

    E-Print Network [OSTI]

    P. F. Roche; C. Packham; D. K. Aitken; R. E. Mason

    2006-10-19T23:59:59.000Z

    Spectroscopy at 8-13 microns with T-ReCS on Gemini-S is presented for 3 galaxies with substantial silicate absorption features, NGC 3094, NGC 7172 and NGC 5506. In the galaxies with the deepest absorption bands, the silicate profile towards the nuclei is well represented by the emissivity function derived from the circumstellar emission from the red supergiant, mu Cephei which is also representative of the mid-infrared absorption in the diffuse interstellar medium in the Galaxy. There is spectral structure near 11.2 microns in NGC 3094 which may be due to a component of crystalline silicates. In NGC 5506, the depth of the silicate absorption increases from north to south across the nucleus, suggestive of a dusty structure on scales of 10s of parsecs. We discuss the profile of the silicate absorption band towards galaxy nuclei and the relationship between the 9.7 micron silicate and 3.4 micron hydrocarbon absorption bands.

  5. Light nuclei production in heavy ion collisions

    E-Print Network [OSTI]

    K. H. Khan; M. K. Suleymanov; Z. Wazir; E. U. Khan; Mahnaz Q. Haseeb; M. Ajaz

    2009-04-14T23:59:59.000Z

    Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

  6. Deeply virtual Compton scattering off nuclei

    SciTech Connect (OSTI)

    Voutier, Eric

    2009-01-01T23:59:59.000Z

    Deeply virtual Compton scattering (DVCS) is the golden exclusive channel for the study of the partonic structure of hadrons, within the universal framework of generalized parton distributions (GPDs). This paper presents the aim and general ideas of the DVCS experimental program off nuclei at the Jefferson Laboratory. The benefits of the study of the coherent and incoherent channels to the understanding of the EMC (European Muon Collaboration) effect are discussed, along with the case of nuclear targets to access neutron GPDs.

  7. Photoproduction of Mesons off Light Nuclei -- the Search for ?-Mesic Nuclei

    E-Print Network [OSTI]

    B. Krusche; F. Pheron; Y. Magrbhi

    2010-11-03T23:59:59.000Z

    Photoproduction of \\eta mesons off light nuclei (d, 3He, 7Li) has been measured at the tagged photon beam of the Mainz MAMI accelerator with the combined Crystal Ball/TAPS detection system. Special attention was given to the threshold behavior of the reactions in view of possible indications for the formation of (quasi-) bound \\eta -nucleus states, so-called \\eta -mesic nuclei. A very strong threshold enhancement of coherent \\eta photoproduction off 3He was found and coherent \\eta photoproduction off 7Li was observed for the first time. Preliminary results will be discussed.

  8. Monte Carlo simulation of the nuclear medium: Fermi gases, nuclei and the role of Pauli potentials

    E-Print Network [OSTI]

    M. A. Perez-Garcia

    2007-08-26T23:59:59.000Z

    The role of Pauli potentials in the semiclassical simulation of Fermi gases at low temperatures is investigated. An alternative Pauli potential to the usual bivariate Gaussian form by Dorso et al. is proposed. This new Pauli potential allows for a simultaneous good reproduction of not only the kinetic energy per particle but also the momentum distribution and the two-body correlation function. The reproduction of the binding energies in finite nuclei in the low and medium mass range is also analyzed. What is found is that given a reasonable short-range atractive nuclear interaction one can include correlation effects in a suitable chosen density dependent Pauli potential.

  9. Mechanisms of neutrinoless double-beta decay: A comparative analysis of several nuclei

    SciTech Connect (OSTI)

    Ali, A. [DESY, Deutsches Elektronen-Synchrotron (Germany); Borisov, A. V., E-mail: borisov@phys.msu.r [Moscow State University (Russian Federation); Zhuridov, D. V. [Scuola Normale Superiore (Italy)

    2010-12-15T23:59:59.000Z

    The neutrinoless double beta decay of several nuclei that are of interest from the experimental point of view ({sup 76}Ge, {sup 82}Se, {sup 100}Mo, {sup 130}Te, and {sup 136}Xe) is investigated on the basis of a general Lorentzinvariant effective Lagrangian describing physics effects beyond the Standard Model. The half-lives and angular-correlation coefficients for electrons are calculated for various decay mechanisms associated, in particular, with the exchange of Majorana neutrinos, supersymmetric particles (with R-parity violation), leptoquarks, and right-handed W{sub R} bosons. The effect of theoretical uncertainties in the values of relevant nuclear matrix elements on decay features is considered.

  10. Neutron-Proton Radii in N \\approx Z Nuclei

    E-Print Network [OSTI]

    N. Auerbach

    2010-06-10T23:59:59.000Z

    A simple formula is derived that describes how the Coulomb interaction affects the proton radius in nuclei. It determines the difference between neutron and proton radii in nuclei with N approx Z. It also provides an estimate for the difference between the radii of the Z core neutrons and the protons in nuclei with a large neutron excess. The results obtained from the derived formula are compared with radii calculated in a Skyrme Hartree-Fock calculation.

  11. Low-energy multipole response in nuclei at finite temperature

    E-Print Network [OSTI]

    Y. F. Niu; N. Paar; D. Vretenar; J. Meng

    2009-06-16T23:59:59.000Z

    The multipole response of nuclei at temperatures T=0-2 MeV is studied using a self-consistent finite-temperature RPA (random phase approximation) based on relativistic energy density functionals. Illustrative calculations are performed for the isoscalar monopole and isovector dipole modes and, in particular, the evolution of low-energy excitations with temperature is analyzed, including the modification of pygmy structures. Both for the monopole and dipole modes, in the temperature range T=1-2 MeV additional transition strength appears at low energies because of thermal unblocking of single-particle orbitals close to the Fermi level. A concentration of dipole strength around 10 MeV excitation energy is predicted in $^{60,62}$Ni, where no low-energy excitations occur at zero temperature. The principal effect of finite temperature on low-energy strength that is already present at zero temperature, e.g. in $^{68}$Ni and $^{132}$Sn, is the spreading of this structure to even lower energy and the appearance of states that correspond to thermally unblocked transitions.

  12. Development of High Precision Timing Counter Based on Plastic Scintillator with SiPM Readout

    E-Print Network [OSTI]

    Paolo W. Cattaneo; Matteo De Gerone; Flavio Gatti; Miki Nishimura; Wataru Ootani; Massimo Rossella; Yusuke Uchiyama

    2014-08-11T23:59:59.000Z

    High-time-resolution counters based on plastic scintillator with silicon photomultiplier (SiPM) readout have been developed for applications to high energy physics experiments for which relatively large-sized counters are required. We have studied counter sizes up to $120\\times40\\times5$ mm^3 with series connection of multiple SiPMs to increase the sensitive area and thus achieve better time resolution. A readout scheme with analog shaping and digital waveform analysis is optimized to achieve the highest time resolution. The timing performance is measured using electrons from a Sr-90 radioactive source, comparing different scintillators, counter dimensions, and types of near-ultraviolet sensitive SiPMs. As a result, a resolution of $\\sigma =42 \\pm 2$ ps at 1 MeV energy deposition is obtained for counter size $60\\times 30 \\times 5$ mm^3 with three SiPMs ($3\\times3$ mm^2 each) at each end of the scintillator. The time resolution improves with the number of photons detected by the SiPMs. The SiPMs from Hamamatsu Photonics give the best time resolution because of their high photon detection efficiency in the near-ultraviolet region. Further improvement is possible by increasing the number of SiPMs attached to the scintillator.

  13. Design and development of a 3He replacement safeguards neutron counter based on 10B-lined proportional detector technology

    SciTech Connect (OSTI)

    Henzlova, Daniela [Los Alamos National Laboratory; Evans, Louise [Los Alamos National Laboratory; Menlove, Howard O. [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Rael, Carlos D. [Los Alamos National Laboratory; Martinez, Isaac P. [Los Alamos National Laboratory; Marlow, Johnna B. [Los Alamos National Laboratory

    2012-07-16T23:59:59.000Z

    This presentation represents an overview of the experimental evaluation of a boron-lined proportional technology performed within an NA-241 sponsored project on testing of boron-lined proportional counters for the purpose of replacement of {sup 3}He technologies. The presented boron-lined technology will be utilized in a design of a full scale safeguards neutron coincidence counter. The design considerations and the Monte Carlo performance predictions for the counter are also presented.

  14. atom nuclei isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    or these equations can be transformed into each other. We proposed a new mechanism of LENR: cooperative processes in the whole system - nuclei+atoms+condensed matter - nuclear...

  15. active galactic nuclei: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for studying a large variety of astrophysical phenomena, ranging from stars and their environment to interstellar and intergalactic medium, active galactic nuclei (AGN) and...

  16. The Structure of Nuclei Far from Stability

    SciTech Connect (OSTI)

    Zganjar, E.F.

    1999-02-25T23:59:59.000Z

    From among a number of important nuclear structure results that have emerged from our research program during the past few years, two stand out as being of extra significance. These are: (a) the identification of a diabatic coexisting structure in {sup 187}Au which arises solely from differences in proton occupation of adjacent oscillator shells, and (b) the realization of a method for estimating EO strength in nuclei and the resulting prediction that the de-excitation of superdeformed bands may proceed, in some cases, by strong EO transitions.

  17. Quantum Monte Carlo calculations for light nuclei

    SciTech Connect (OSTI)

    Wiringa, R.B.

    1998-08-01T23:59:59.000Z

    Quantum Monte Carlo calculations of ground and low-lying excited states for nuclei with A {le} 8 are made using a realistic Hamiltonian that fits NN scattering data. Results for more than 30 different (j{sup {prime}}, T) states, plus isobaric analogs, are obtained and the known excitation spectra are reproduced reasonably well. Various density and momentum distributions and electromagnetic form factors and moments have also been computed. These are the first microscopic calculations that directly produce nuclear shell structure from realistic NN interactions.

  18. Short-Distance Structure of Nuclei

    E-Print Network [OSTI]

    D. W. Higinbotham; E. Piasetzky; S. A. Wood

    2009-08-02T23:59:59.000Z

    One of Jefferson Lab's original missions was to further our understanding of the short-distance structure of nuclei. In particular, to understand what happens when two or more nucleons within a nucleus have strongly overlapping wave-functions; a phenomena commonly referred to as short-range correlations. Herein, we review the results of the (e,e'), (e,e'p) and (e,e'pN) reactions that have been used at Jefferson Lab to probe this short-distance structure as well as provide an outlook for future experiments.

  19. Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices ?

    E-Print Network [OSTI]

    I. Adachi; T. Sumiyoshi; K. Hayashi; N. Iida; R. Enomoto; K. Tsukada; R. Suda; S. Matsumoto; K. Natori; M. Yokoyama; H. Yokogawa

    1994-01-01T23:59:59.000Z

    To identify ? ± and K ± in the region of 1.0 ? 2.5 GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to ?/K separation up to a few GeV/c with an efficiency greater than 90 % was considered. 1

  20. Mechanism of supporting sub-communicator collectives with O(64) counters as opposed to one counter for each sub-communicator

    DOE Patents [OSTI]

    Kumar, Sameer; Mamidala, Amith R.; Ratterman, Joseph D.; Blocksome, Michael; Miller, Douglas

    2013-09-03T23:59:59.000Z

    A system and method for enhancing barrier collective synchronization on a computer system comprises a computer system including a data storage device. The computer system includes a program stored in the data storage device and steps of the program being executed by a processor. The system includes providing a plurality of communicators for storing state information for a bather algorithm. Each communicator designates a master core in a multi-processor environment of the computer system. The system allocates or designates one counter for each of a plurality of threads. The system configures a table with a number of entries equal to the maximum number of threads. The system sets a table entry with an ID associated with a communicator when a process thread initiates a collective. The system determines an allocated or designated counter by searching entries in the table.

  1. Beyond mean-field study of elastic and inelastic electron scattering off nuclei

    E-Print Network [OSTI]

    J. M. Yao; M. Bender; P. -H. Heenen

    2015-01-21T23:59:59.000Z

    Electron scattering provides a powerful tool to determine charge distributions and transition densities of nuclei. This tool will soon be available for short-lived neutron-rich nuclei. [Purpose] Beyond mean-field methods have been successfully applied to the study of excitation spectra of nuclei in the whole nuclear chart. These methods permit to determine energies and transition probabilities starting from an effective in-medium nucleon-nucleon interaction but without other phenomenological ingredients. Such a method has recently been extended to calculate the charge density of nuclei deformed at the mean-field level of approximation [J. M. Yao et al., Phys. Rev. C86, 014310 (2012)]. The aim of this work is to further extend the method to the determination of transition densities between low-lying excited states. [Method] The starting point of our method is a set of Hartree-Fock-Bogoliubov wave functions generated with a constraint on the axial quadrupole moment and using a Skyrme energy density functional. Correlations beyond the mean field are introduced by projecting mean-field wave functions on angular-momentum and particle number and by mixing the symmetry restored wave functions.[Results] We give in this paper detailed formulae derived for the calculation of densities and form factors. These formulae are rather easy to obtain when both initial and final states are $0^+$ states but are far from being trivial when one of the states has a finite $J$-value. Illustrative applications to $^{24}$Mg and to the even-mass $^{58-68}$Ni have permitted to analyse the main features of our method, in particular the effect of deformation on densities and form factors. An illustration calculation of both elastic and inelastic scattering form factors is presented....

  2. Search for long lived heaviest nuclei beyond the valley of stability

    E-Print Network [OSTI]

    P. Roy Chowdhury; C. Samanta; D. N. Basu

    2008-02-26T23:59:59.000Z

    The existence of long lived superheavy nuclei (SHN) is controlled mainly by spontaneous fission and $\\alpha$-decay processes. According to microscopic nuclear theory, spherical shell effects at Z=114, 120, 126 and N=184 provide the extra stability to such SHN to have long enough lifetime to be observed. To investigate whether the so-called "stability island" could really exist around the above Z, N values, the $\\alpha$-decay half lives along with the spontaneous fission and $\\beta$-decay half lives of such nuclei are studied. The $\\alpha$-decay half lives of SHN with Z=102-120 are calculated in a quantum tunneling model with DDM3Y effective nuclear interaction using $Q_\\alpha$ values from three different mass formulae prescribed by Koura, Uno, Tachibana, Yamada (KUTY), Myers, Swiatecki (MS) and Muntian, Hofmann, Patyk, Sobiczewski (MMM). Calculation of spontaneous fission (SF) half lives for the same SHN are carried out using a phenomenological formula and compared with SF half lives predicted by Smolanczuk {\\it et al}. Possible source of discrepancy between the calculated $\\alpha$-decay half lives of some nuclei and the experimental data of GSI, JINR-FLNR, RIKEN are discussed. In the region of Z=106-108 with N$\\sim$ 160-164, the $\\beta$-stable SHN $^{268}_{106}Sg_{162}$ is predicted to have highest $\\alpha$-decay half life ($T_\\alpha \\sim 3.2hrs$) using $Q_\\alpha$ value from MMM. Interestingly, it is much greater than the recently measured $T_\\alpha$ ($\\sim 22s$) of deformed doubly magic $^{270}_{108}Hs_{162}$ nucleus. A few fission-survived long-lived SHN which are either $\\beta$-stable or having large $\\beta$-decay half lives are predicted to exist near $^{294}110_{184}$, $^{293}110_{183}$, $^{296}112_{184}$ and $^{298}114_{184}$. These nuclei might decay predominantly through $\\alpha$-particle emission.

  3. Relativistic mean field plus exact pairing approach to open shell nuclei

    E-Print Network [OSTI]

    Wei-Chia Chen; J. Piekarewicz; A. Volya

    2013-11-20T23:59:59.000Z

    Background: Pairing correlations play a critical role in determining numerous properties of open-shell nuclei. Traditionally, they are included in a mean-field description of atomic nuclei through the approximate Bardeen-Cooper-Schrieffer or Hartree-Fock-Bogoliubov formalism. Purpose: We propose a new hybrid ''relativistic-mean-field-plus-pairing'' approach in which pairing is treated exactly so the number of particles is conserved. To verify the reliability of the formalism, we apply it to the study of both ground-state properties and isoscalar monopole excitations of the Tin isotopes. Methods: Accurately-calibrated relativistic mean-field models supplemented by an exact treatment of pairing correlations are used to compute ground-state observables along the isotopic chain in Tin. In turn, ground-state densities are used as input to the calculation of giant monopole resonances through a constrained-relativistic approach. Results: We compute a variety of ground-state observables sensitive to pairing correlations as well as the evolution of giant monopole energies along the isotopic chain in Tin. Whereas ground-state properties are consistent with experiment, we find that pairing correlations have a minor effect on the giant monopole energies. Conclusions: A new mean-field-plus-pairing approach is introduced to compute properties of open-shell nuclei. The formalism provides an efficient and powerful alternative to the computation of both ground-state properties and monopole energies of open-shell nuclei. We find ground-state properties to be well reproduced in this approach. However, as many have concluded before us, we find that pairing correlations are unlikely to provide an answer to the question of ''why is Tin so soft?''

  4. MMIII* by M. Kosticwww.kostic.niu.edu Error or Uncertainty Analysis

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    Gas Analysis SO2 , NO, NO2 , CO, CO2 , THC, O2Sample Tanks Particle Probe Gas Probe Exhaust DMA1 © MMIII* by M. Kosticwww.kostic.niu.edu Unleashing Error or Uncertainty Analysis of Measurement - Differential Mobility Analyzer CNC ­ Condensation Nuclei Counter HPLPC ­ High Pressure Large Particle Counter

  5. New Measurements of High-Momentum Nucleons and Short-Range Structures in Nuclei

    E-Print Network [OSTI]

    Filippone, Bradley W.

    We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei ...

  6. Method for enhancing selectivity and recovery in the fractional flotation of particles in a flotation column

    SciTech Connect (OSTI)

    Klunder, Edgar B. (Bethel Park, PA)

    2011-08-09T23:59:59.000Z

    The method relates to particle separation from a feed stream. The feed stream is injected directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. A froth breaker generates a reflux stream and a concentrate stream, and the reflux stream is injected into the froth zone to mix with the interstitial liquid between bubbles in the froth zone. Counter-current flow between the plurality of bubbles and the interstitial liquid facilitates the attachment of higher hydrophobicity particles to bubble surfaces as lower hydrophobicity particles detach. The height of the feed stream injection and the reflux ratio may be varied in order to optimize the concentrate or tailing stream recoveries desired based on existing operating conditions.

  7. The mechanism of sound generation in the interaction between a shock wave and two counter-rotating vortices

    E-Print Network [OSTI]

    Zhang, Yong-Tao

    The mechanism of sound generation in the interaction between a shock wave and two counter the mechanism of sound generation in the interaction between a shock wave and two counter-rotating vortices to the shock interaction with two isolated vortices, in which the sound wave generated by the interaction

  8. Statistics of particle time-temperature histories.

    SciTech Connect (OSTI)

    Hewson, John C.; Lignell, David O.; Sun, Guangyuan

    2014-10-01T23:59:59.000Z

    Particles in non - isothermal turbulent flow are subject to a stochastic environment tha t produces a distribution of particle time - temperature histories. This distribution is a function of the dispersion of the non - isothermal (continuous) gas phase and the distribution of particles relative to that gas phase. In this work we extend the one - dimensional turbulence (ODT) model to predict the joint dispersion of a dispersed particle phase and a continuous phase. The ODT model predicts the turbulent evolution of continuous scalar fields with a model for the cascade of fluctuations to smaller sc ales (the 'triplet map') at a rate that is a function of the fully resolved one - dimens ional velocity field . Stochastic triplet maps also drive Lagrangian particle dispersion with finite Stokes number s including inertial and eddy trajectory - crossing effect s included. Two distinct approaches to this coupling between triplet maps and particle dispersion are developed and implemented along with a hybrid approach. An 'instantaneous' particle displacement model matches the tracer particle limit and provide s an accurate description of particle dispersion. A 'continuous' particle displacement m odel translates triplet maps into a continuous velocity field to which particles respond. Particles can alter the turbulence, and modifications to the stochastic rate expr ession are developed for two - way coupling between particles and the continuous phase. Each aspect of model development is evaluated in canonical flows (homogeneous turbulence, free - shear flows and wall - bounded flows) for which quality measurements are ava ilable. ODT simulations of non - isothermal flows provide statistics for particle heating. These simulations show the significance of accurately predicting the joint statistics of particle and fluid dispersion . Inhomogeneous turbulence coupled with the in fluence of the mean flow fields on particles of varying properties alter s particle dispersion. The joint particle - temperature dispersion leads to a distribution of temperature histories predicted by the ODT . Predictions are shown for the lower moments an d the full distributions of the particle positions, particle - observed gas temperatures and particle temperatures. An analysis of the time scales affecting particle - temperature interactions covers Lagrangian integral time scales based on temperature autoco rrelations, rates of temperature change associated with particle motion relative to the temperature field and rates of diffusional change of temperatures. These latter two time scales have not been investigated previously; they are shown to be strongly in termittent having peaked distributions with long tails. The logarithm of the absolute value of these time scales exhibits a distribution closer to normal. A cknowledgements This work is supported by the Defense Threat Reduction Agency (DTRA) under their Counter - Weapons of Mass Destruction Basic Research Program in the area of Chemical and Biological Agent Defeat under award number HDTRA1 - 11 - 4503I to Sandia National Laboratories. The authors would like to express their appreciation for the guidance provi ded by Dr. Suhithi Peiris to this project and to the Science to Defeat Weapons of Mass Destruction program.

  9. Searching for E(5) behavior in nuclei

    SciTech Connect (OSTI)

    Clark, R.M.; Cromaz, M.; Deleplanque, M.A.; Descovich, M.; Diamond, R.M; Fallon, P.; Lee, I.Y.; Macchiavelli, A.O.; Mahmud, H.; Rodriguez-Vieitez, E.; Stephens, F.S.; Ward, D.

    2004-01-01T23:59:59.000Z

    The properties of even-even nuclei with 30 {le} Z {le} 82, A {ge} 60 have been examined to find examples displaying the characteristics of E(5) critical-point behavior for the shape transition from a spherical vibrator to a triaxially soft rotor. On the basis of the known experimental state energies and E2 transition strengths, the best candidates that were identified are {sup 102}Pd, {sup 106,108}Cd, {sup 124}Te, {sup 128}Xe, and {sup 134}Ba. The closest agreement between experimental data and the predictions of E(5) is for {sup 128}Xe and for the previously suggested example of {sup 134}Ba. It is proposed that {sup 128}Xe may be a new example of a nucleus at the E(5) critical point.

  10. Helium Nuclei in Quenched Lattice QCD

    E-Print Network [OSTI]

    T. Yamazaki; Y. Kuramashi; A. Ukawa; for the PACS-CS Collaboration

    2009-12-08T23:59:59.000Z

    We present results for the binding energies for He and ^3He nuclei calculated in quenched lattice QCD at the lattice spacing of a = 0.128 fm with a heavy quark mass corresponding to m_pi = 0.8 GeV. Enormous computational cost for the nucleus correlation functions is reduced by avoiding redundancy of equivalent contractions stemming from permutation symmetry of protons or neutrons in the nucleus and various other symmetries. To distinguish a bound state from an attractive scattering state, we investigate the volume dependence of the energy difference between the nucleus and the free multi-nucleon states by changing the spatial extent of the lattice from 3.1 fm to 12.3 fm. A finite energy difference left in the infinite spatial volume limit leads to the conclusion that the measured ground states are bounded. It is also encouraging that the measured binding energies and the experimental ones show the same order of magnitude.

  11. Subthreshold Photofission of Even-Even Nuclei

    SciTech Connect (OSTI)

    Kadmensky, S.G.; Rodionova, L.V. [Voronezh State University, Universitetskaya pl. 1, Voronezh, 394693 (Russian Federation)

    2005-09-01T23:59:59.000Z

    Within quantum-mechanical fission theory, the angular distributions of fragments originating from the subthreshold photofission of the even-even nuclei {sup 232}Th, {sup 234}U, {sup 236}U, {sup 238}U, {sup 238}Pu, {sup 240}Pu, and {sup 242}Pu are analyzed for photon energies below 7 MeV. Special features of various fission channels are assessed under the assumption that the fission barrier has a two-humped shape. It is shown that the maximum value of the relative orbital angular momentum L{sub m} of fission fragments can be found upon taking into account deviations from the predictions of A. Bohr's formula for the angular distributions of fission fragments. The result is L{sub m} {approx_equal} 30. The existence of an 'isomeric shelf' for the angular distributions of fragments from {sup 236}U and {sup 238}U photofission in the low-energy region is confirmed.

  12. Neutrino Nucleosynthesis of radioactive nuclei in supernovae

    E-Print Network [OSTI]

    Sieverding, A; Langanke, K; Martínez-Pinedo, G; Heger, A

    2015-01-01T23:59:59.000Z

    We study the neutrino-induced production of nuclides in explosive supernova nucleosynthesis for progenitor stars with solar metallicity and initial main sequence masses between 15 M$_\\odot$ and 40 M$_\\odot$. We improve previous investigations i) by using a global set of partial differential cross sections for neutrino-induced charged- and neutral-current reactions on nuclei with charge numbers $Z < 76 $ and ii) by considering modern supernova neutrino spectra which have substantially lower average energies compared to those previously adopted in neutrino nucleosynthesis studies. We confirm the production of $^7$Li, $^{11}$B, $^{138}$La, and $^{180}$Ta by neutrino nucleosynthesis, albeit at slightly smaller abundances due to the changed neutrino spectra. We find that for stars with a mass smaller than 20 M$_\\odot$, $^{19}$F is produced mainly by explosive nucleosynthesis while for higher mass stars it is produced by the $\

  13. EMC and polarized EMC effects in Nuclei

    SciTech Connect (OSTI)

    Ian Cloet; Wolfgang Bentz; Anthony Thomas

    2006-05-23T23:59:59.000Z

    We determine nuclear structure functions and quark distributions for {sup 7}Li, {sup 11}B, {sup 15}N and {sup 27}Al. For the nucleon bound state we solve the covariant quark-diquark equations in a confining Nambu--Jona-Lasinio model, which yields excellent results for the free nucleon structure functions. The nucleus is described using a relativistic shell model, including mean scalar and vector fields that couple to the quarks in the nucleon. The nuclear structure functions are then obtained as a convolution of the structure function of the bound nucleon with the light-cone nucleon distributions. We find that we are readily able to reproduce the EMC effect in finite nuclei and confirm earlier nuclear matter studies that found a large polarized EMC effect.

  14. EMC and Polarized EMC Effects in Nuclei

    E-Print Network [OSTI]

    I. C. Cloet; W. Bentz; A. W. Thomas

    2006-05-24T23:59:59.000Z

    We determine nuclear structure functions and quark distributions for $^7$Li, $^{11}$B, $^{15}$N and $^{27}$Al. For the nucleon bound state we solve the covariant quark-diquark equations in a confining Nambu--Jona-Lasinio model, which yields excellent results for the free nucleon structure functions. The nucleus is described using a relativistic shell model, including mean scalar and vector fields that couple to the quarks in the nucleon. The nuclear structure functions are then obtained as a convolution of the structure function of the bound nucleon with the light-cone nucleon distributions. We find that we are readily able to reproduce the EMC effect in finite nuclei and confirm earlier nuclear matter studies that found a large polarized EMC effect.

  15. Microfluidic cell counter with embedded optical fibers fabricated by femtosecond laser ablation

    E-Print Network [OSTI]

    . Scott, and J. R. Mabesa, Jr., "Manufacturing by laser direct-write of three-dimensional devicesMicrofluidic cell counter with embedded optical fibers fabricated by femtosecond laser ablation using femtosecond laser ablation and anodic bonding. In a first application, we constructed a cell

  16. A Performance Counter Based Workload Characterization on Blue Gene/P

    E-Print Network [OSTI]

    John, Lizy Kurian

    A Performance Counter Based Workload Characterization on Blue Gene/P Karthik Ganesan Lizy John V--IBM's Blue Gene/P, the second generation of the Blue Gene supercomputer is designed with a Universal Perfor instrument applications and get a profound insight into its execution on the Blue Gene/P system which could

  17. Gain dispersion in Visible Light Photon Counters as a function of counting rate

    SciTech Connect (OSTI)

    Bross, A.; /Fermilab; Buscher, V.; /Freiburg U.; Estrada, J.; /Fermilab; Ginther, G.; /Rochester U.; Molina, J.; /Rio de Janeiro State U.

    2005-03-01T23:59:59.000Z

    We present measurements of light signals using Visible Light Photon Counters (VLPC), that indicate an increase in gain dispersion as the counting rate increases. We show that this dispersion can be understood on the basis of a recent observation of localized field reduction in VLPCs at high input rates.

  18. Tri-Met's Experience With Automatic Passenger Counter and Automatic Vehicle Location Systems

    E-Print Network [OSTI]

    Bertini, Robert L.

    on an earlier draft. #12;Introduction The Tri-County Metropolitan Transportation District of Oregon (TriTri-Met's Experience With Automatic Passenger Counter and Automatic Vehicle Location Systems James State University Portland, OR 97207 This report is benefited from interviews of Tri-Met staff involved

  19. Functionalized Graphene as a Catalytic Counter Electrode in Dye-Sensitized

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    %).1,2 In typical DSSC architectures, the photon-induced oxida- tion of a dye occurs at a TiO2 photoanode, while but typically requires a platinum catalyst in DSSC operation.3 5 Platinum has high catalytic activity toward I3, since platinum is a precious metal, much incentive exists to develop DSSC counter electrodes using

  20. CounterIntelligence: Augmented Reality Kitchen Leonardo Bonanni, Chia-Hsun Lee, Ted Selker

    E-Print Network [OSTI]

    ]: Consumer products, Kitchen counter, refrigerator, cabinets, sink, range. INTRODUCTION Domestic kitchens on nearly every surface of the space: the refrigerator door, range, countertop, cabinets, and faucet (see projection on the refrigerator (1), the range (2), the cabinet (3), the faucet(4) and drawers(5). RELATED

  1. DRAM Decay: Using Decay Counters to Reduce Energy Consumption in DRAMs

    E-Print Network [OSTI]

    Lee, Hsien-Hsin "Sean"

    DRAM Decay: Using Decay Counters to Reduce Energy Consumption in DRAMs Mrinmoy Ghosh Hsien-Hsin S. Lee School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta, GA 30332 technology they use. For each refresh in a DRAM row, the stored information in each cell is read out

  2. Determining TSP, PM10 & PM2.5 using the Coulter Counter Multisizer

    E-Print Network [OSTI]

    Raina, Madhulika

    1996-01-01T23:59:59.000Z

    PMIO concentrations using standard high volume samplers and the Coulter Counter Multisizer. The FEVol/Coulter method can be used to calculate TSP, PMIO and PM2.5 using just one exposed filter. It will assist in regulating PMIO air pollution and can...

  3. Demonstration: in-plane scattering of beads on a target; sticky marbles; Geiger counter and sources

    E-Print Network [OSTI]

    Boal, David

    Demonstration: in-plane scattering of beads on a target; sticky marbles; Geiger counter and sources, and the hole is about 5 cm in diameter. In the demo, 20 beads are rolled at random positions, and about 5 fall with no top or bottom. We drop 10,000 sticky marbles at random into the box, covering an area 1 m by 1 m

  4. TransportAware IP Routers: a Builtin Protection Mechanism to Counter DDoS Attacks

    E-Print Network [OSTI]

    Wang, Haining

    is a powerful built­in pro­ tection mechanism to counter DDoS attacks, reducing the vulnerability of Internet Wang and Kang G. Shin Real­Time Computing Laboratory Department of Electrical Engineering and Computer isolation by the current IP routers exposes their vulnerability to Distributed Denial of Service (DDo

  5. Position-sensitive proportional counter with low-resistance metal-wire anode

    DOE Patents [OSTI]

    Kopp, Manfred K. (Oak Ridge, TN)

    1980-01-01T23:59:59.000Z

    A position-sensitive proportional counter circuit is provided which allows the use of a conventional (low-resistance, metal-wire anode) proportional counter for spatial resolution of an ionizing event along the anode of the counter. A pair of specially designed active-capacitance preamplifiers are used to terminate the anode ends wherein the anode is treated as an RC line. The preamplifiers act as stabilized active capacitance loads and each is composed of a series-feedback, low-noise amplifier, a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction and handling of the anodes, and stabilizes the anode resistivity at high count rates (>10.sup.6 counts/sec).

  6. Mesoscale distribution of zooplankton biomass in the northeast Atlantic Ocean determined with an Optical Plankton Counter

    E-Print Network [OSTI]

    Mesoscale distribution of zooplankton biomass in the northeast Atlantic Ocean determined Available online 2 June 2009 Keywords: Zooplankton Biomass Size distribution Mesoscale eddies Optical plankton counter Pelagic environment Northeast Atlantic Ocean a b s t r a c t We examined the mesoscale

  7. Instrumenting Linear Algebra Energy Consumption via On-chip Energy Counters

    E-Print Network [OSTI]

    California at Berkeley, University of

    Instrumenting Linear Algebra Energy Consumption via On-chip Energy Counters James Demmel Andrew to lists, requires prior specific permission. #12;Instrumenting linear algebra energy consumption via on consumption is still a prevalent and growing problem within the computing sector. To evaluate energy

  8. Safety Analysis of an Airbag System using Probabilistic FMEA and Probabilistic Counter Examples

    E-Print Network [OSTI]

    Leue, Stefan

    Safety Analysis of an Airbag System using Probabilistic FMEA and Probabilistic Counter Examples Failure mode and effects analysis (FMEA) is a technique to reason about possible system hazards that result from system or system component failures. Traditionally, FMEA does not take the probabilities

  9. Alternative description of particle shower longitudinal profile

    E-Print Network [OSTI]

    Ter-Antonyan, Samvel

    2015-01-01T23:59:59.000Z

    Alternative parameterization of particle shower longitudinal profile is presented. The accuracy of obtained shower profile description is about 2-3% for the 0-1500 g/cm^2 atmosphere slant depths and primary H, He,... Fe nuclei in 1 PeV-10 EeV energy range. It is shown that the shape of shower profile depends only on the nucleon energy, whereas the maximum shower size also depends on the energy of parental nucleus. Results are based on the CORSIKA simulated shower profiles and are presented in comparison with Gaisser-Hillas parameterization.

  10. Summary of nuclear and particle astrophysics sessions

    SciTech Connect (OSTI)

    Wilkes, R.J. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)

    1995-07-10T23:59:59.000Z

    Astrophysics is gaining increased attention from the particle and nuclear physics communities, as budget cuts, delays, and cancellations limit opportunities for breakthrough research at accelerator laboratories. Observations of cosmic rays (protons and nuclei), gamma rays and neutrinos present a variety of puzzles whose eventual solution will shed light on many issues ranging from the nature of fundamental interactions at extreme energies to the mechanisms of astrophysical sources. Several important detectors are just beginning full-scale operation and others are beginning construction. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  11. Many-Body Interactions of Neutrinos with Nuclei - Observables

    E-Print Network [OSTI]

    O. Lalakulich; K. Gallmeister; U. Mosel

    2014-09-24T23:59:59.000Z

    Background: The total inclusive cross sections obtained for quasielastic (QE) scattering in the Mini Booster Neutrino Experiment (MiniBooNE) are significantly larger than those calculated by all models based on the impulse approximation and using the world average value for the axial mass of $M_A \\approx 1 \\GeV$. This discrepancy has led to various, quite different explanations in terms of increased axial masses, changes in the functional form of the axial form factor, increased vector strength in nuclei, and initial two-particle interactions. This is disconcerting since the neutrino energy reconstruction depends on the reaction mechanism. Purpose: We investigate whether exclusive observables, such as nucleon knock-out, can be used to distinguish between the various proposed reaction mechanisms. We determine the influence of 2p-2h excitations on the energy reconstruction. Method: We use the Giessen Boltzmann--Uehling--Uhlenbeck (GiBUU) model to predict numbers and spectra of knock-out nucleons. The model is extended by incorporating a simple, but realistic treatment of initial 2p-2h excitations. Results: We show numbers and spectra of knock-out nucleons and show their sensitivity to the presence of 2p-2h initial excitations. We also discuss the influence of 2p-2h excitations on the neutrino energy reconstruction. Conclusions: 2p-2h excitations do lead to an increase in the number $n$ of knock-out nucleons for $n \\ge 2$ while only the $n=1$ knock-out remains a clean signal of true QE scattering. The spectra of knock-out nucleons do also change, but their qualitative shape remains as before. In the energy reconstruction 2p-2h interactions lead to a downward shift of the reconstructed energy; this effect of 2p-2h excitations disappears at higher energies because the 2p-2h influence is spread out over a wider energy range.

  12. Search milli-charged particles at SLAC

    SciTech Connect (OSTI)

    Langeveld, W.G.J. [Stanford Univ., CA (United States)

    1997-01-01T23:59:59.000Z

    Particles with electric charge q {triple_bond} Qe {le} 10{sup -3} e and masses in the range 1-1000 MeV/c{sup 2} are not excluded by present experiments or by astrophysical or cosmological arguments. A beam dump experiment uniquely suited to the detection of such {open_quotes}milli-charged{close_quotes} particles has been carried out at SLAC, utilizing the short-duration pulses of the SLC electron beam to establish a tight coincidence window for the signal. The detector, a large scintillation counter sensitive to very small energy depositions, provided much greater sensitivity than previous searches. Analysis of the data leads to the exclusion of a substantial portion of the charge-mass plane. In this report, a preliminary mass-dependent upper limit is presented for the charge of milli-charged particles, ranging from Q = 1.7 x 10{sup -5} at milli-charged particle mass 0.1 MeV/c{sup 2} to Q = 9.5 x 10{sup -4} at 100 MeV/c{sup 2}.

  13. Performance evaluation of PM?? and high-volume air samplers using a Coulter Counter Particle Size Analyzer

    E-Print Network [OSTI]

    Herber, Douglas John

    1988-01-01T23:59:59.000Z

    ) for SA-1200 samplers place downwind of a gin processing stripper cotton. . 36 Comparison of average PSDs for dust captured on exposed filters of the HiVol and SA-1200 samplers placed downwind of a gin processing stripper cotton. 37 10 Relationship... of measured PM10 concentration to "actual" PMIO concentration (using HiVol/Coulter process) for SA-321A samplers place downwind of a gin processing stripper cotton . . 38 Comparison of average PSDs for dust captured on exposed filters of the HiVol and SA...

  14. Relativistic mean field calculations in neutron-rich nuclei

    SciTech Connect (OSTI)

    Gangopadhyay, G.; Bhattacharya, Madhubrata [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Roy, Subinit [Saha Institute of Nuclear Physics, Block AF, Sector 1, Kolkata- 700 064 (India)

    2014-08-14T23:59:59.000Z

    Relativistic mean field calculations have been employed to study neutron rich nuclei. The Lagrange's equations have been solved in the co-ordinate space. The effect of the continuum has been effectively taken into account through the method of resonant continuum. It is found that BCS approximation performs as well as a more involved Relativistic Continuum Hartree Bogoliubov approach. Calculations reveal the possibility of modification of magic numbers in neutron rich nuclei. Calculation for low energy proton scattering cross sections shows that the present approach reproduces the density in very light neutron rich nuclei.

  15. New measurements of the EMC effect in light nuclei

    SciTech Connect (OSTI)

    A. Daniel

    2009-12-01T23:59:59.000Z

    Modifications of structure functions in nuclei (EMC effect) suggest that the nuclear quark distribution function is not just the incoherent sum of the proton and neutron distributions, and made clear the importance of nuclear effects even in high energy measurements. Jefferson Lab experiment E03-103 made precise measurements of the EMC effect in few-body and heavy nuclei with emphasis on the large x region. Data from the light nuclei suggests that the nuclear dependence of the high x quark distribution may depend on the nucleon's local environment, rather than being a purely bulk effect.

  16. New measurements of the EMC effect in light nuclei

    SciTech Connect (OSTI)

    Daniel, A. [Dept. of Physics and Astronomy, Ohio University, Athens OH 45701 (United States)

    2009-12-17T23:59:59.000Z

    Modifications of structure functions in nuclei (EMC effect) suggest that the nuclear quark distribution function is not just the incoherent sum of the proton and neutron distributions, and made clear the importance of nuclear effects even in high energy measurements. Jefferson Lab experiment E03-103 made precise measurements of the EMC effect in few-body and heavy nuclei with emphasis on the large x region. Data from the light nuclei suggests that the nuclear dependence of the high x quark distribution may depend on the nucleon's local environment, rather than being a purely bulk effect.

  17. Excited collective states of heavy even-even nuclei

    SciTech Connect (OSTI)

    Nadirbekov, M. S.; Yuldasheva, G. A. [Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan)] [Uzbek Academy of Sciences, Institute of Nuclear Physics (Uzbekistan)

    2013-03-15T23:59:59.000Z

    Quadrupole-type collective excitations of even-even nuclei are analyzed. In this analysis, transverse {gamma} vibrations of the nuclear surface are taken into account effectively, while longitudinal beta vibrations remain free. A potential energy of the exponential form is used for free surface longitudinal beta vibrations. The behavior of the energy levels of excited states in the ground-state, {beta}, and {gamma} bands of heavy nuclei is studied, and the predictive potential of the model used is demonstrated for transfermium nuclei.

  18. {gamma}-ray Spectroscopy of Proton Drip-Line Nuclei in the A{approx}130 Region using SPIRAL beams

    SciTech Connect (OSTI)

    Stezowski, O.; Guinet, D.; Lautesse, Ph.; Meyer, M.; Redon, N.; Rosse, B.; Schmitt, Ch. [IPN Lyon, IN2P3/CNRS, Universite Claude Bernard Lyon-1, F-69622 Villeurbanne Cedex (France); Nolan, P. J.; Boston, A. J.; Cooper, R.; Dimmock, M.; Gros, S.; McGuirck, B.; Paul, E. S.; Petri, M.; Scraggs, H.; Turk, G. [Oliver Lodge Laboratory, University of Liverpool, P.O. Box 147, Liverpool L69 7ZE (United Kingdom); De France, G.; Bhattachasyya, S.; Mukherjee, G. [GANIL, B.P. 55027, F-14076 Caen Cedex (France)] (and others)

    2008-11-11T23:59:59.000Z

    A fusion-evaporation experiment has been performed with a SPIRAL {sup 76}Kr radioactive beam in order to study the deformation of rare-earth nuclei near the proton drip-line. The experimental setup consisted in the EXOGAM {gamma}-array, coupled to the light-charged particles (LCP) DIAMANT detector and to the VAMOS heavy-ion spectrometer. The difficulties inherent to such measurements are enlightened. The coupling between EXOGAM and DIAMANT has been used to decrease the huge background caused by the radioactivity of the beam. It further permits assigning new {gamma}-ray transitions to specific residual nuclei. A {gamma}-ray belonging to the {sup 130}Pm level scheme has thus been observed for the first time.

  19. Testing Skyrme energy-density functionals with the QRPA in low-lying vibrational states of rare-earth nuclei

    E-Print Network [OSTI]

    J. Terasaki; J. Engel

    2011-05-19T23:59:59.000Z

    Although nuclear energy density functionals are determined primarily by fitting to ground state properties, they are often applied in nuclear astrophysics to excited states, usually through the quasiparticle random phase approximation (QRPA). Here we test the Skyrme functionals SkM* and SLy4 along with the self-consistent QRPA by calculating properties of low-lying vibrational states in a large number of well-deformed even-even rare-earth nuclei. We reproduce trends in energies and transition probabilities associated with gamma-vibrational states, but our results are not perfect and indicate the presences of multi-particle-hole correlations that are not included in the QRPA. The Skyrme functional SkM* performs noticeably better than SLy4. In a few nuclei, changes in the treatment of the pairing energy functional have a significant effect. The QRPA is less successful with "beta-vibrational" states than with the gamma-vibrational states.

  20. SVSM/Combinatorics Assignment 5 One Pile Nim 1. Consider the game G1 which starts with one pile of 20 counters.

    E-Print Network [OSTI]

    Reiter, Harold

    SVSM/Combinatorics Assignment 5 One Pile Nim 1. Consider the game G1 which starts with one pile. 2. Consider the game G2 which starts with one pile of 20 counters. The rules allow a player to take with one pile of 20 counters. The rules allow a player to take 1, 2, or 6 counters on each turn. Denote

  1. The effect of fuel and engine design on diesel exhaust particle size distributions

    SciTech Connect (OSTI)

    Baumgard, K.J.; Johnson, J.H. [Michigan Technological Univ., Houghton, MI (United States)

    1996-09-01T23:59:59.000Z

    The objective of this research was to obtain diesel particle size distributions from a 1988 and a 1991 diesel engine using three different fuels and two exhaust control technologies (a ceramic particle trap and an oxidation catalytic converter). The particle size distributions from both engines were used to develop models to estimate the composition of the individual size particles. Nucleation theory of the H{sub 2}O and H{sub 2}SO{sub 4} vapor is used to predict when nuclei-mode particles will form in the dilution tunnel. Combining the theory with the experimental data, the conditions necessary in the dilution tunnel for particle formation are predicted. The paper also contains a discussion on the differences between the 1988 and 1991 engine`s particle size distributions. The results indicated that nuclei mode particles (0.0075--0.046 {micro}m) are formed in the dilution tunnel and consist of more than 80% H{sub 2}O-H{sub 2}SO{sub 4} particles when using the 1988 engine and 0.29 wt% sulfur fuel. Nucleation theory indicated that H{sub 2}O-H{sub 2}SO{sub 4} particles may form during dilution at 0.03 wt% fuel sulfur levels and above. The 1991 engine was designed for lower particulate emissions than the 1988 engine and the 1991 engine`s accumulation mode particles (0.046-1.0 {micro}m) were reduced more than 80% by volume compared to the 1988 engine using the same low sulfur fuel. The particle size composition model indicated that using low sulfur fuel and the 1991 engine, the nuclei mode contained more than 45% of the total solid particles and over 85% of the soluble organic fraction.

  2. Particle Identification in the NIMROD-ISiS Detector Array

    E-Print Network [OSTI]

    S. Wuenschel; K. Hagel; L. W. May; R. Wada; S. J. Yennello

    2009-03-04T23:59:59.000Z

    Interest in the influence of the neutron-to-proton (N/Z) ratio on multifragmenting nuclei has demanded an improvement in the capabilities of multi-detector arrays as well as the companion analysis methods. The particle identification method used in the NIMROD-ISiS 4 $\\pi$ array is described. Performance of the detectors and the analysis method are presented for the reaction of 86Kr+64Ni at 35MeV/u.

  3. Particle Identification in the NIMROD-ISiS Detector Array

    SciTech Connect (OSTI)

    Wuenschel, S.; Hagel, K.; May, L. W.; Wada, R.; Yennello, S. J. [Texas A and M University Cyclotron Institute College Station TX 77843 (United States)

    2009-03-10T23:59:59.000Z

    Interest in the influence of the neutron-to-proton (N/Z) ratio on multifragmenting nuclei has demanded an improvement in the capabilities of multi-detector arrays as well as the companion analysis methods. The particle identification method used in the NIMROD-ISiS 4{pi} array is described. Performance of the detectors and the analysis method are presented for the reaction of {sup 86}Kr+{sup 64}Ni at 35 MeV/u.

  4. {alpha}-cluster states in N{ne}Z nuclei

    SciTech Connect (OSTI)

    Goldberg, V. Z.; Rogachev, G. V. [Cyclotron Institute, Texas A and M University, College Station, TX (United States); Department of Physics, Florida State University, Tallahassee, FL (United States) and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing (United States)

    2012-10-20T23:59:59.000Z

    The importance of studies of {alpha}-Cluster structure in N{ne}Z light nuclei is discussed. Spin-parity assignments for the low-lying levels in {sup 10}C are suggested.

  5. Scissors mode of Gd nuclei studied from resonance neutron capture

    SciTech Connect (OSTI)

    Kroll, J.; Baramsai, B.; Becker, J. A. [Charles University in Prague, CZ-180 00 Prague 8 (Czech Republic); North Carolina State University, Raleigh, NC 27695 (United States) and Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); and others

    2012-10-20T23:59:59.000Z

    Spectra of {gamma} rays following the neutron capture at isolated resonances of stable Gd nuclei were measured. The objectives were to get new information on photon strength of {sup 153,155-159}Gd with emphasis on the role of the M1 scissors-mode vibration. An analysis of the data obtained clearly indicates that the scissors mode is coupled not only to the ground state, but also to all excited levels of the nuclei studied. The specificity of our approach ensures unbiasedness in estimating the sumed scissors-mode strength {Sigma}B(M1){up_arrow}, even for odd product nuclei, for which conventional nuclear resonance fluorescence measurements yield only limited information. Our analysis indicates that for these nuclei the sum {Sigma}B(M1){up_arrow} increases with A and for {sup 157,159}Gd it is significantly higher compared to {sup 156,158}Gd.

  6. Magnetic Moments of Light Nuclei from Lattice Quantum Chromodynamics

    E-Print Network [OSTI]

    Beane, S.?R.

    We present the results of lattice QCD calculations of the magnetic moments of the lightest nuclei, the deuteron, the triton, and [superscript 3]He, along with those of the neutron and proton. These calculations, performed ...

  7. Progress and challenges in the theory of nuclei

    E-Print Network [OSTI]

    D. J. Dean

    2007-09-04T23:59:59.000Z

    Nuclear theory today aims for a comprehensive theoretical framework that can describe all nuclei. I discuss recent progress in this pursuit and the associated challenges as we move forward.

  8. astatine compound nuclei: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Fissibility of compound nuclei Nuclear Experiment (arXiv) Summary: Collisions between 248Cm and 48Ca are...

  9. The variability of warm absorbers in Active Galactic Nuclei

    E-Print Network [OSTI]

    Gibson, Robert R. (Robert Ross)

    2006-01-01T23:59:59.000Z

    This thesis presents three studies of warm (photoionized) absorber variability in Active Galactic Nuclei (AGN) using high-resolution X-ray spectra provided by the Chandra High Energy Transmission Grating (HETG). The first ...

  10. Nuclear structure/nuclei far from stability

    SciTech Connect (OSTI)

    Casten, R.F.; Garrett, J.D.; Moller, P.; Bauer, W.W.; Brenner, D.S.; Butler, G.W.; Crawford, J.E.; Davids, C.N.; Dyer, P.L.; Gregorich, K.; Hagbert, E.G.; Hamilton, W.D.; Harar, S.; Haustein, P.E.; Hayes, A.C.; Hoffman, D.C.; Hsu, H.H.; Madland, D.G.; Myers, W.D.; Penttila, H.T.; Ragnarsson, I.; Reeder, P.L.; Robertson, G.H.; Rowley, N.; Schreiber, F.; Seifert, H.L.; Sherrill, B.M.; Siciliano, E.R.; Sprouse, G.D.; Stephens, F

    1990-01-01T23:59:59.000Z

    This report outlines some of the nuclear structure topics discussed at the Los Alamos Workshop on the Science of Intense Radioactive Ion Beams (RIB). In it we also tried to convey some of the excitement of the participants for utilizing RIBs in their future research. The introduction of radioactive beams promises to be a major milestone for nuclear structure perhaps even more important than the last such advance in beams based on the advent of heavy-ion accelerators in the 1960's. RIBs not only will allow a vast number of new nuclei to be studies at the extremes of isospin, but the variety of combinations of exotic proton and neutron configurations should lead to entirely new phenomena. A number of these intriguing new studies and the profound consequences that they promise for understanding the structure of the atomic nucleus, nature's only many-body, strongly-inteacting quantum system, are discussed in the preceeding sections. However, as with any scientific frontier, the most interesting phenomena probably will be those that are not anticipated--they will be truly new.

  11. Charge Radii of beta-Stable Nuclei

    E-Print Network [OSTI]

    G. K. Nie

    2005-12-07T23:59:59.000Z

    In previous work it was shown that the radius of nucleus R is determined by the alpha-cluster structure and can be estimated on the number of alpha-clusters disregarding to the number of excess neutrons. A hypothesis also was made that the radius R_m of a beta-stable isotope, which is actually measured at electron scattering experiments, is determined by the volume occupied by the matter of the core plus the volume occupied by the peripheral alpha-clusters. In this paper it is shown that the condition R_m = R restricts the number of excess neutrons filling the core to provide the beta-stability. The number of peripheral clusters can vary from 1 to 5 and the value of R for heavy nuclei almost do not change, whereas the number of excess neutrons should change with the number of peripheral clusters to get the value of R_m close to R. It can explain the path of the beta-stability and its width. The radii R_m of the stable isotopes with 12 =< Z =< 83 and the alpha-decay isotopes with 84 =< Z =< 116 that are stable to beta-decay have been calculated.

  12. Electromagnetic Studies of Mesons, Nucleons, and Nuclei

    SciTech Connect (OSTI)

    Baker, Oliver K.

    2013-08-20T23:59:59.000Z

    Professor Baker was a faculty member at Hampton University in Hampton, Virginia, and, jointly, a Staff Physicist at Jefferson Lab in nearby Newport News from September 1989 to July 2006. The Department of Energy (DOE) funded the grant DE-FG02-97ER41035 Electromagnetic Studies of Mesons, Nucleons, and Nuclei, while Baker was in this joint appointment. Baker sent a closeout report on these activities to Hampton University’s Sponsored Research Office some years ago, shortly after joining Yale University in 2006. In the period around 2001, the research grant with Baker as the Principal Investigator (PI) was put under the supervision of Professor Liguang Tang at Hampton University. Baker continued to pursue the research while in this join appointment, however the administrative responsibilities with the DOE and with Hampton University rested with Professor Tang after 2001, to my recollection. What is written in this document is from Baker’s memory of the research activities, which he has not pursued since joining the Yale University faculty.

  13. Nuclear diagnostic for fast alpha particles

    DOE Patents [OSTI]

    Grisham, Larry R. (Lawrence Township, Mercer County, NJ); Post, Jr., Douglass E. (Belle Mead, NJ); Dawson, John M. (Pacific Palisades, CA)

    1986-01-01T23:59:59.000Z

    Measurement of the velocity distribution of confined energetic alpha particles resulting from deuterium-tritium fusion reactions in a magnetically contained plasma is provided. The fusion plasma is seeded with energetic boron neutrals for producing, by means of the reaction .sup.10 B (.alpha.,n) .sup.13 N reaction, radioactive nitrogen nuclei which are then collected by a probe. The radioactivity of the probe is then measured by conventional techniques in determining the energy distribution of the alpha particles in the plasma. In a preferred embodiment, diborane gas (B.sub.2 H.sub.6) is the source of the boron neutrals to produce .sup.13 N which decays almost exclusively by positron emission with a convenient half-life of 10 minutes.

  14. Transverse polarization of $?$ hyperons from quasireal photoproduction on nuclei

    E-Print Network [OSTI]

    The HERMES Collaboration; A. Airapetian; N. Akopov; Z. Akopov; E. C. Aschenauer; W. Augustyniak; R. Avakian; A. Avetissian; E. Avetisyan; S. Belostotski; N. Bianchi; H. P. Blok; A. Borissov; J. Bowles; I. Brodski; V. Bryzgalov; J. Burns; M. Capiluppi; G. P. Capitani; E. Cisbani; G. Ciullo; M. Contalbrigo; P. F. Dalpiaz; W. Deconinck; R. De Leo; L. De Nardo; E. De Sanctis; M. Diefenthaler; P. Di Nezza; M. Düren; M. Ehrenfried; G. Elbakian; F. Ellinghaus; R. Fabbri; A. Fantoni; L. Felawka; S. Frullani; D. Gabbert; G. Gapienko; V. Gapienko; F. Garibaldi; G. Gavrilov; V. Gharibyan; F. Giordano; S. Gliske; M. Golembiovskaya; C. Hadjidakis; M. Hartig; D. Hasch; A. Hillenbrand; M. Hoek; Y. Holler; I. Hristova; Y. Imazu; A. Ivanilov; H. E. Jackson; H. S. Jo; S. Joosten; R. Kaiser; G. Karyan; T. Keri; E. Kinney; A. Kisselev; N. Kobayashi; V. Korotkov; V. Kozlov; P. Kravchenko; V. G. Krivokhijine; L. Lagamba; L. Lapikás; I. Lehmann; P. Lenisa; A. López Ruiz; W. Lorenzon; X. -G. Lu; B. -Q. Ma; D. Mahon; N. C. R. Makins; S. I. Manaenkov; Y. Mao; B. Marianski; A. Martinez de la Ossa; H. Marukyan; C. A. Miller; Y. Miyachi; A. Movsisyan; V. Muccifora; M. Murray; A. Mussgiller; E. Nappi; Y. Naryshkin; A. Nass; M. Negodaev; W. -D. Nowak; L. L. Pappalardo; R. Perez-Benito; P. E. Reimer; A. R. Reolon; C. Riedl; K. Rith; G. Rosner; A. Rostomyan; J. Rubin; D. Ryckbosch; Y. Salomatin; F. Sanftl; A. Schäfer; G. Schnell; K. P. Schüler; B. Seitz; T. -A. Shibata; V. Shutov; M. Stancari; M. Statera; E. Steffens; J. J. M. Steijger; J. Stewart; F. Stinzing; S. Taroian; A. Terkulov; R. Truty; A. Trzcinski; M. Tytgat; A. Vandenbroucke; Y. Van Haarlem; C. Van Hulse; D. Veretennikov; V. Vikhrov; I. Vilardi; S. Wang; S. Yaschenko; Z. Ye; W. Yu; V. Zagrebelnyy; D. Zeiler; B. Zihlmann; P. Zupranski

    2014-10-03T23:59:59.000Z

    The transverse polarization of $\\Lambda$ hyperons was measured in inclusive quasireal photoproduction for various target nuclei ranging from hydrogen to xenon. The data were obtained by the HERMES experiment at HERA using the 27.6 GeV lepton beam and nuclear gas targets internal to the lepton storage ring. The polarization observed is positive for light target nuclei and is compatible with zero for krypton and xenon.

  15. EMC effect for light nuclei: new results from Jefferson Lab

    SciTech Connect (OSTI)

    Daniel, A. [Dept. of Physics and Astronomy, Ohio University, Athens OH 45701 (United States)

    2011-10-24T23:59:59.000Z

    High energy lepton scattering has been the primary tool for mapping out the quark distributions of nucleons and nuclei. Measurements of deep inelastic scattering in nuclei show that the quark distributions in heavy nuclei are not simply the sum of the quark distributions of the constituent proton and neutron, as one might expect for a weakly bound system. This modification of the quark distributions in nuclei is known as the EMC effect. I will discuss the results from Jefferson Lab (JLab) experiment E03-103, a precise measurement of the EMC effect in few-body nuclei with emphasis on the large x region. Data from the light nuclei suggests that the nuclear dependence of the high x quark distribution may depend on the nucleon's local environment, rather than being a purely bulk effect. In addition, I will also discuss about a future experiment at the upgraded 12 GeV Jefferson Lab facility which will further investigate the role of the local nuclear environment and the influence of detailed nuclear structure to the modification of quark distributions.

  16. EMC effect for light nuclei: New results from Jefferson Lab

    SciTech Connect (OSTI)

    Aji Daniel

    2011-10-01T23:59:59.000Z

    High energy lepton scattering has been the primary tool for mapping out the quark distributions of nucleons and nuclei. Measurements of deep inelastic scattering in nuclei show that the quark distributions in heavy nuclei are not simply the sum of the quark distributions of the constituent proton and neutron, as one might expect for a weakly bound system. This modification of the quark distributions in nuclei is known as the EMC effect. I will discuss the results from Jefferson Lab (JLab) experiment E03-103, a precise measurement of the EMC effect in few-body nuclei with emphasis on the large x region. Data from the light nuclei suggests that the nuclear dependence of the high x quark distribution may depend on the nucleon's local environment, rather than being a purely bulk effect. In addition, I will also discuss about a future experiment at the upgraded 12 GeV Jefferson Lab facility which will further investigate the role of the local nuclear environment and the influence of detailed nuclear structure to the modification of quark distributions.

  17. Cerenkov Counter for In-situ Groundwater Monitoring of Sr90

    SciTech Connect (OSTI)

    Runkle, Robert C.; Brodzinski, Ronald L.; Jordan, David V.; Hartman, John S.; Hensley, Walter K.; Maynard, Melody A.; Sliger, William A.; Smart, John E.; Todd, Lindsay C.

    2005-01-15T23:59:59.000Z

    Groundwater contamination from 90Sr is an environmental challenge posed to present and former nuclear weapons related sites. Traditional methods of extracting groundwater samples and performing laboratory analyses are expensive, time consuming and induce significant disposal challenges. We present here a prototype counter capable of measuring in-situ 90Sr groundwater concentrations at or above the drinking water limit of 8 pCi/L. The beta-decay of 90Sr, and its daughter 90Y, emits high-energy electrons which create Cerenkov light. Photomultiplier tubes convert the Cerenkov light into an electronic pulse which then undergoes signal processing with standard electronics. Concentrations near the drinking water limit can be measured in a matter of hours if they exist in secular equilibrium. The prototype counter is compact, can be operated by a single person and transmits the results to a central monitoring location.

  18. Simulations of Lithium-Based Neutron Coincidence Counter for Gd-Loaded Fuel

    SciTech Connect (OSTI)

    Cowles, Christian C.; Kouzes, Richard T.; Siciliano, Edward R.

    2014-10-31T23:59:59.000Z

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Lithium-Based Alternative Neutron Detection Technology Coincidence Counting for Gd-loaded Fuels at Pacific Northwest National Laboratory for the development of a lithium-based neutron coincidence counter for nondestructively assaying Gd loaded nuclear fuel. This report provides results from MCNP simulations of a lithium-based coincidence counter for the possible measurement of Gd-loaded nuclear fuel. A comparison of lithium-based simulations and UNCL-II simulations with and without Gd loaded fuel is provided. A lithium-based model, referred to as PLNS3A-R1, showed strong promise for assaying Gd loaded fuel.

  19. The fluctuation energy balance in non-suspended fluid-mediated particle transport

    E-Print Network [OSTI]

    Pähtz, Thomas; Ho, Tuan-Duc; Valance, Alexandre; Kok, Jasper F

    2015-01-01T23:59:59.000Z

    Here we compare two extreme regimes of non-suspended fluid-mediated particle transport, transport in light and heavy fluids ("saltation" and "bedload", respectively), regarding their particle fluctuation energy balance. From direct numerical simulations, we surprisingly find that the ratio between collisional and fluid drag dissipation of fluctuation energy is significantly larger in saltation than in bedload, even though the contribution of interparticle collisions to transport of momentum and energy is much smaller in saltation due to the low concentration of particles in the transport layer. We conclude that the much higher frequency of high-energy particle-bed impacts ("splash") in saltation is the cause for this counter-intuitive behavior. Moreover, from a comparison of these simulations to Particle Tracking Velocimetry measurements which we performed in a wind tunnel under steady transport of fine and coarse sand, we find that turbulent fluctuations of the flow produce particle fluctuation energy at an ...

  20. Countering the Master Narrative: Muslims and Islam in Science Fiction, Fantasy, and Comics

    E-Print Network [OSTI]

    Hankins, Rebecca

    2010-08-16T23:59:59.000Z

    science fiction stories include: The Cathedral, a futuristic look at a world where seminaries encourage multiculturalism and the quest for tolerance is taken a step too far, published in Citizen Culture Magazine (Feb 2005); Hajar's Long Walk and First... ?Countering the Master Narrative: Muslims and Islam in Science Fiction, Fantasy and Comics.? Rebecca Hankins Science Fiction Symposium-April 15, 2010 The influence that science fiction, fantasy and comic literature has and continues to have...

  1. High-efficiency He-3 proportional counter for the detection of delayed neutrons

    SciTech Connect (OSTI)

    Loaiza, D.J.

    1998-03-01T23:59:59.000Z

    The present work examines a high-neutron efficiency detector used to measure delayed neutron techniques. The measurement of delayed neutrons requires a detector system that has high neutron efficiency and a low dead- time. The detection system must also have low gamma-ray sensitivity, and in addition must be insensitive to small sample displacement. The operating characteristics of the high-efficiency He-3 proportional counter used for the measurement of {beta}{sub i}-delayed neutrons is reported here.

  2. Scaling of Counter-Current Imbibition Process in Low-Permeability Porous Media, TR-121

    SciTech Connect (OSTI)

    Kvoscek, A.R.; Zhou, D.; Jia, L.; Kamath, J.

    2001-01-17T23:59:59.000Z

    This project presents the recent work on imaging imbibition in low permeability porous media (diatomite) with X-ray completed tomography. The viscosity ratio between nonwetting and wetting fluids is varied over several orders of magnitude yielding different levels of imbibition performance. Also performed is mathematical analysis of counter-current imbibition processes and development of a modified scaling group incorporating the mobility ratio. This modified group is physically based and appears to improve scaling accuracy of countercurrent imbibition significantly.

  3. Solution In-Line Alpha Counter (SILAC) Instruction Manual-Version 4.00

    SciTech Connect (OSTI)

    Steven M. Alferink; Joel E. Farnham; Malcolm M. Fowler; Amy S. Wong

    2002-06-01T23:59:59.000Z

    The Solution In-Line Alpha Counter (SILAC) provides near real-time alpha activity measurements of aqueous solutions in gloveboxes located in the Plutonium Facility (TA-55) at Los Alamos National Laboratory (LANL). The SILAC detector and its interface software were first developed by Joel Farnham at LANL [1]. This instruction manual describes the features of the SILAC interface software and contains the schematic and fabrication instructions for the detector.

  4. Unveiling the counter-rotating nature of the kinematically distinct core in NGC5813 with MUSE

    E-Print Network [OSTI]

    Krajnovic, Davor; Urrutia, Tanya; Emsellem, Eric; Carollo, C Marcella; Shirazi, Maryam; Bacon, Roland; Contini, Thierry; Epinat, Benoit; Kamann, Sebastian; Martinsson, Thomas; Steinmetz, Matthias

    2015-01-01T23:59:59.000Z

    MUSE observations of NGC5813 reveal a complex structure in the velocity dispersion map, previously hinted by SAURON observations. The structure is reminiscent of velocity dispersion maps of galaxies comprising two counter-rotating discs, and may explain the existence of the kinematically distinct core (KDC). Further evidence for two counter-rotating components comes from the analysis of the higher moments of the stellar line-of-sight velocity distributions and fitting MUSE spectra with two separate Gaussian line-of-sight velocity distributions. The emission-line kinematics show evidence of being linked to the present cooling flows and the buoyant cavities seen in X-rays. We detect ionised gas in a nuclear disc-like structure, oriented like the KDC, which is, however, not directly related to the KDC. We build an axisymmetric Schwarzschild dynamical model, which shows that the MUSE kinematics can be reproduced well with two counter-rotating orbit families, characterised by relatively low angular momentum compon...

  5. Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices

    E-Print Network [OSTI]

    I. Adachi et al

    1994-12-13T23:59:59.000Z

    To identify $\\pi^{\\pm}$ and $K^{\\pm}$ in the region of $1.0\\sim 2.5$ GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to $\\pi / K$ separation up to a few GeV/c %in the momentum range of $1.0 \\sim 2.5$ GeV/c with an efficiency greater than $90$ \\% was considered.

  6. A Search for "Dwarf" Seyfert Nuclei. VI. Properties of Emission-Line Nuclei in Nearby Galaxies

    E-Print Network [OSTI]

    Luis C. Ho; Alexei V. Filippenko; Wallace L. W. Sargent

    2002-10-02T23:59:59.000Z

    We use the database from Paper III to quantify the global and nuclear properties of emission-line nuclei in the Palomar spectroscopic survey of nearby galaxies. We show that the host galaxies of Seyferts, LINERs, and transition objects share remarkably similar large-scale properties and local environments. The distinguishing traits emerge on nuclear scales. Compared with LINERs, Seyfert nuclei are an order of magnitude more luminous and exhibit higher electron densities and internal extinction. We suggest that Seyfert galaxies possess characteristically more gas-rich circumnuclear regions, and hence a more abundant fuel reservoir and plausibly higher accretion rates. The differences between the ionization state of the narrow emission-line regions of Seyferts and LINERs can be partly explained by the differences in their nebular properties. Transition-type objects are consistent with being composite (LINER/\\hii) systems. With very few exceptions, the stellar population within the central few hundred parsecs of the host galaxies is uniformly old, a finding that presents a serious challenge to starburst or post-starburst models for these objects. Seyferts and LINERs have virtually indistinguishable velocity fields as inferred from their line widths and line asymmetries. All three classes of objects obey a strong correlation between line width and line luminosity. We argue that the angular momentum content of circumnuclear gas may be an important factor in determining whether a nucleus becomes active. Finally, we discuss some possible complications for the unification model of Seyfert galaxies posed by our observations. (Abridged)

  7. A study of particle generation during laser ablation withapplications

    SciTech Connect (OSTI)

    Liu, Chunyi

    2005-08-12T23:59:59.000Z

    A study has been made of the generation of particles during laser ablation and has included size distribution measurements and observation of the formation processes. The particle size distribution with respect to different laser parameters was obtained in-line using a differential mobility analyzer (DMA) and a particle counter. The experimental results show that the particle size varies with laser energy, laser pulsewidth, ambient gas flow rate and sample properties. The results serve as a basis for controlling the size of nanoparticles generated by laser ablation. Laser shadowgraph imaging was used to study mass ejection processes and mechanisms. At higher laser irradiance, some particles were ejected in the liquid and even in the solid phase. Time-resolved images show the propagation of the shockwaves: external shockwaves propagate outward and decelerate, and internal shockwaves reflect back and forth between the gas contact surface and the sample surface. The internal shockwave is proposed to cause the ejection of liquid particles when the internal shockwave strikes the liquid molten layer. A simulation based on vapor plume expansion was carried out and provides satisfactory agreement with experimental results. Different material properties result in different particle ejection behavior:particle ejection for most materials including metals result in a conically shaped envelope for the ejected material while ejection for silicon resembles a liquid jet. The difference in density change when the materials melt was proposed to be an important factor in the different ejection behavior. The characteristics of particles generated by laser ablation have a strong influence on the chemical analysis of the irradiated sample. Large particles are more difficult to completely vaporize and ionize, and induced preferential vaporization causes fractionation (i.e. a detected chemical composition that differs from the sample material). Large particles also result in spikes in measurements using inductively coupled plasma mass spectrometry (ICP-MS) which result in errors. Three different methods were employed to study the effects of particle size on chemical analysis: generating smaller particles utilizing a fs laser, filtering out larger particles with a cascade impactor and altering the size distribution by using a second pulse to fracture particles generated from the first pulse. It was found that the chemical composition of the particles varies with particle size. The variation of the composition with respect to particle size was analyzed and it was proposed that it was related to the vapor formed particles condensing on larger ejected liquid droplets.

  8. High-precision description and new properties of a spin-1 particle in a magnetic field

    E-Print Network [OSTI]

    Alexander J. Silenko

    2014-06-09T23:59:59.000Z

    The exact Foldy-Wouthuysen Hamiltonian is derived for a pointlike spin-1 particle with a normal magnetic moment in a nonuniform magnetic field. For a uniform magnetic field, it is exactly separated into terms linear and quadratic in spin. New unexpected properties of a particle with an anomalous magnetic moment are found. Spin projections of a particle moving in a uniform magnetic field are not integer and the tensor polarization is asymmetric in the plane orthogonal to the field. Previously described spin-tensor effects caused by the tensor magnetic polarizability exist not only for nuclei but also for pointlike particles.

  9. Low lying electric dipole excitations in nuclei of the rare earth region

    SciTech Connect (OSTI)

    von Brentano, P.; Zilges, A.; Herzberg, R.D. [Koeln Univ. (Germany). Inst. fuer Kernphysik; Zamfir, N.V. [Brookhaven National Lab., Upton, NY (United States); Kneissl, U.; Heil, R.D.; Pitz, H.H. [Stuttgart Univ. (Germany). Inst. fuer Strahlenphysik; Wesselborg, C. [Giessen Univ. (Germany). Inst. fuer Kernphysik

    1992-10-01T23:59:59.000Z

    From many experiments with low energy photon scattering on deformed rare earth nuclei we have obtained detailed information about the distribution of electric dipole strength below 4 MeV. Apart from some weaker transitions between 2 and 4 MeV we observed one, and sometimes two, very strong El-groundstate transitions around 1.5 MeV in all examined nuclei. They arise from the de-excitation of the bandheads of the (J{sup {pi}},K)=(l{sup {minus}},0) and (J{sup {pi}},K)=(l{sup {minus}},1) octupole vibrational bands. It is shown that the decay branching ratios and the absolute transition strengths of these states can be reproduced rather well with an improved T(El)-operator in the sdf-Interacting Boson Model. Another class of octupole states has been investigated in the region of the semimagic nucleus {sup 142}Nd. Here a quintuplet of collective excitations around 3.5 MeV is expected due to the coupling of the 3{minus}-octupole vibration with the 2+-quadrupole vibration. We performed photon scattering experiments on the odd A neighboring nucleus {sup 141}Pr and found first evidence for the existence of 3{sup {minus}}{circle_times}2+{circle_times}particle-states.

  10. Non-Axial Octupole Deformations and Tetrahedral Symmetry in Heavy Nuclei

    SciTech Connect (OSTI)

    Mazurek, Katarzyna [Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow (Poland); Dudek, Jerzy [Institut de Recherches Subatomiques, F-67037 Strasbourg Cedex 2 (France); Universite Louis Pasteur, F-67037 Strasbourg Cedex 2 (France)

    2005-11-21T23:59:59.000Z

    The total energies of about 120 nuclei in the Thorium region have been calculated within the macroscopic-microscopic method in the 5-dimensional space of deformation parameters {alpha}20, {alpha}22, {alpha}30, {alpha}32 and {alpha}40. The macroscopic energy term contains the nuclear surface-curvature dependence as proposed within the LSD approach. The microscopic energies are calculated with the Woods-Saxon single particle potential employing the universal set of parameters.We study a possible presence of the octupole axial and non-axial degrees of freedom all-over in the ({beta}, {gamma})-plane focussing on the ground-states, secondary minima and in the saddle points. In fact, a competition between axial and tri-axial octupole deformation parameters is obtained at the saddle points and in the secondary minima for many isotones with N > 136. The presence of the tetrahedral symmetry minima is predicted in numerous nuclei in the discussed region, although most of the time at relatively high excitation energies.

  11. The second skin approach : skin strain field analysis and mechanical counter pressure prototyping for advanced spacesuit design

    E-Print Network [OSTI]

    Bethke, Kristen (Kristen Ann)

    2005-01-01T23:59:59.000Z

    The primary aim of this thesis is to advance the theory of advanced locomotion mechanical counter pressure (MCP) spacesuits by studying the changes in the human body shape during joint motion. Two experiments take advantage ...

  12. PERFORMANCE OF THE LEAD/LIQUID ARGON SHOWER COUNTER SYSTEM OF THE MARK II DETECTOR AT SPEAR

    E-Print Network [OSTI]

    Abrams, G.S.

    2013-01-01T23:59:59.000Z

    of California. PERFORMANCE OF THE LEAD/LIQUID ARGON SHOWERMark II detector is a large lead/liquid argon system of theof-flight information, lead/liquid argon shower counters,

  13. Establishment and testing of a whole body counter for the Texas A&M Nuclear Science Center 

    E-Print Network [OSTI]

    Baca, Bernadette Doris

    1997-01-01T23:59:59.000Z

    The establishment and testing of a whole body counter would benefit the Texas A&M Nuclear Science Center (NSC) Health Physics staff and workers by allowing better assessment of a worker's internal exposure. Presently NSC ...

  14. Induction of linear tracks of DNA double-strand breaks by -particle irradiation of

    E-Print Network [OSTI]

    Cai, Long

    Induction of linear tracks of DNA double- strand breaks by -particle irradiation of cells Jan Stap1,4, Przemek M Krawczyk1,4, Carel H Van Oven1, Gerrit W Barendsen2, Jeroen Essers3, Roland Kanaar3 & Jacob describe a procedure for induction of easily recognizable linear arrays of DSBs in nuclei of adherent

  15. Spectroscopy of {Beta}-Delayed Charged Particles at Projectile Fragment Separators

    SciTech Connect (OSTI)

    Janas, Zenon

    2000-12-31T23:59:59.000Z

    The combination of projectile fragmentation reactions and in-flight separation has proved to be a powerful tool to produce nuclei at the limits of stability. Decay studies of very neutron-deficient projectile fragments led to the discovery of several new {beta}-delayed particle emitters. Basic principles of the method are described and various aspects of extracting interesting spectroscopic information from {beta}-delayed particle studies at projectile fragment separators are discussed.

  16. Study of Even-Even/Odd-Even/Odd-Odd Nuclei in Zn-Ga-Ge Region in the Proton-Neutron IBM/IBFM/IBFFM

    SciTech Connect (OSTI)

    Yoshida, N. [Faculty of Informatics, Kansai University, Takatsuki 569-1095 (Japan); Brant, S. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Zuffi, L. [Dipartimento di Fisica dell'Universita di Milano and Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, Milano 20133 (Italy)

    2009-08-26T23:59:59.000Z

    We study the even-even, odd-even and odd-odd nuclei in the region including Zn-Ga-Ge in the proton-neutron IBM and the models derived from it: IBM2, IBFM2, IBFFM2. We describe {sup 67}Ga, {sup 65}Zn, and {sup 68}Ga by coupling odd particles to a boson core {sup 66}Zn. We also calculate the beta{sup +}-decay rates among {sup 68}Ge, {sup 68}Ga and {sup 68}Zn.

  17. Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals

    E-Print Network [OSTI]

    Dobaczewski, J; Bender, M; Robledo, L M; Shi, Yue

    2015-01-01T23:59:59.000Z

    We calculate properties of the ground and excited states of nuclei in the nobelium region for proton and neutron numbers of 92 energy-density-functional (EDF) approaches, based on covariant, Skyrme, and Gogny functionals, each within two different parameter sets. A comparative analysis of the results obtained for odd-even mass staggerings, quasiparticle spectra, and moments of inertia allows us to identify single-particle and shell effects that are characteristic to these different models and to illustrate possible systematic uncertainties related to using the EDF modelling

  18. PAMELA's Measurements of Magnetospheric Effects on High Energy Solar Particles

    E-Print Network [OSTI]

    Adriani, O; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bravar, U; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; Christian, E C; De Donato, C; de Nolfo, G A; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krutkov, S Y; Kvashnin, A N; Lee, M; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergé, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Ryan, J M; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stochaj, S; Stozhkov, Y I; Thakur, N; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N

    2015-01-01T23:59:59.000Z

    The nature of particle acceleration at the Sun, whether through flare reconnection processes or through shocks driven by coronal mass ejections (CMEs), is still under scrutiny despite decades of research. The measured properties of solar energetic particles (SEPs) have long been modeled in different particle-acceleration scenarios. The challenge has been to disentangle to the effects of transport from those of acceleration. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument, enables unique observations of SEPs including composition and the angular distribution of the particles about the magnetic field, i.e. pitch angle distribution, over a broad energy range (>80 MeV) -- bridging a critical gap between space-based measurements and ground-based. We present high-energy SEP data from PAMELA acquired during the 2012 May 17 SEP event. These data exhibit differential anisotropies and thus transport features over the instrument rigidity range. SEP protons exhibit two dist...

  19. Production of thorium-229 using helium nuclei

    DOE Patents [OSTI]

    Mirzadeh, Saed (Knoxville, TN) [Knoxville, TN; Garland, Marc Alan (Knoxville, TN) [Knoxville, TN

    2010-12-14T23:59:59.000Z

    A method for producing .sup.229Th includes the steps of providing .sup.226Ra as a target material, and bombarding the target material with alpha particles, helium-3, or neutrons to form .sup.229Th. When neutrons are used, the neutrons preferably include an epithermal neutron flux of at least 1.times.10.sup.13 n s.sup.-1cm.sup.-2. .sup.228Ra can also be bombarded with thermal and/or energetic neutrons to result in a neutron capture reaction to form .sup.229Th. Using .sup.230Th as a target material, .sup.229Th can be formed using neutron, gamma ray, proton or deuteron bombardment.

  20. Quarks and gluons in hadrons and nuclei

    SciTech Connect (OSTI)

    Close, F.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))

    1989-01-01T23:59:59.000Z

    These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. 38 refs.

  1. Superheavy nuclei with the vector self-coupling of the $?$-meson in the relativistic mean-field theory

    E-Print Network [OSTI]

    A A Saldanha; A R Farhan; M M Sharma

    2009-09-02T23:59:59.000Z

    We have studied properties and shell structure of the superheavy elements from Z=102 to Z=120 within the framework of the RMF theory. The region of study spans nuclides with neutron numbers N=150-190. The Lagrangian model NL-SV1 with the inclusion of the vector self-coupling of the omega-meson has been employed in this work. We have performed RMF + BCS calculations for an axially deformed configuration of nuclei. The ground-state binding energies, single-particle properties and quadrupole deformation of nuclei have been obtained from the mean-field minimizations. Two-neutron separation energies, $Q_\\alpha$ values and alpha-decay half-life have been evaluated. It is shown that a large number of nuclides exhibit the phenomenon of shape-coexistence over a significant region of the superheavy elements. Shape coexistence of a prolate and an oblate shape is prevalent in nuclides far below N=184, whilst nuclei in the vicinity of N=184 tend to show a shape coexistence between a spherical and an oblate shape. The shell structure and 2-neutron separation energies obtained with the RMF theory reinforce the neutron number N=184 as a major magic number. It is shown that the neutron number N=172 acts akin to a magic number in the deformed region. It is suggested that the combination Z=120 and N=172 has the potential of being a doubly magic number in the superheavy region.

  2. Study of Nuclei and Elementary Particles At Low and Intermediate Energies

    SciTech Connect (OSTI)

    Robert D. McKeown

    2013-02-27T23:59:59.000Z

    The primary activity associated with this DOE grant was the construction, commissioning, operation, and analysis of results of the KamLAND experiment. KamLAND is a large (1kT) liquid scintillator neutrino detector located deep underground in the Kamioka mine in Japan. This effort was a spectacular scientific success, with a major discovery of neutrino oscillations in the â??solarâ?ť sector and the pioneering measurement of geoneutrinos due to radioactive decay within the earth. During the final year of the grant period, effort was devoted to developing the new Daya Bay reactor neutrino experiment in China.

  3. Leading twist nuclear shadowing phenomena in hard processes with nuclei

    SciTech Connect (OSTI)

    Leonid Frankfurt, Vadim Guzey, Mark Strikman

    2012-03-01T23:59:59.000Z

    We present and discuss the theory and phenomenology of the leading twist theory of nuclear shadowing which is based on the combination of the generalization of Gribov-Glauber theory, QCD factorization theorems, and HERA QCD analysis of diffraction in lepton-proton deep inelastic scattering (DIS). We apply this technique for the analysis of a wide range of hard processes with nuclei-inclusive DIS on deuterons, medium-range and heavy nuclei, coherent and incoherent diffractive DIS with nuclei, and hard diffraction in proton-nucleus scattering - and make predictions for the effect of nuclear shadowing in the corresponding sea quark and gluon parton distributions. We also analyze the role of the leading twist nuclear shadowing in generalized parton distributions in nuclei and certain characteristics of final states in nuclear DIS. We discuss the limits of applicability of the leading twist approximation for small x scattering off nuclei and the onset of the black disk regime and methods of detecting it. It will be possible to check many of our predictions in the near future in the studies of the ultraperipheral collisions at the Large Hadron Collider (LHC). Further checks will be possible in pA collisions at the LHC and forward hadron production at Relativistic Heavy Ion Collider (RHIC). Detailed tests will be possible at an Electon-Ion Collider (EIC) in USA and at the Large Hadron-Electron Collider (LHeC) at CERN.

  4. Advanced Characterization of Particles and Particle-Cell Interactions...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Characterization of Particles and Particle-Cell Interactions Advanced Characterization of Particles and Particle-Cell Interactions 2004 Diesel Engine Emissions Reduction (DEER)...

  5. Dynamics of Carroll Particles

    E-Print Network [OSTI]

    Eric Bergshoeff; Joaquim Gomis; Giorgio Longhi

    2014-05-31T23:59:59.000Z

    We investigate particles whose dynamics is invariant under the Carroll group. Although a single free such Carroll particle has no non-trivial dynamics (`the Carroll particle does not move') we show that there exists non-trivial dynamics for a set of interacting Carroll particles. Furthermore, we gauge the Carroll algebra and couple the Carroll particle to these gauge fields. It turns out that for such a coupled system even a single Carroll particle can have non-trivial dynamics.

  6. ENHANCED ACCRETION RATES OF STARS ON SUPERMASSIVE BLACK HOLES BY STAR-DISK INTERACTIONS IN GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Just, Andreas; Yurin, Denis; Makukov, Maxim; Berczik, Peter; Omarov, Chingis; Spurzem, Rainer [Astronomisches Rechen-Institut, Zentrum fuer Astronomie, Universitaet Heidelberg, Moenchhof-Strasse 12-14, D-69120 Heidelberg (Germany); Vilkoviskij, Emmanuil Y., E-mail: just@ari.uni-heidelberg.de [Fesenkov Astrophysical Institute, Observatory 23, 050020 Almaty (Kazakhstan)

    2012-10-10T23:59:59.000Z

    We investigate the dynamical interaction of a central star cluster surrounding a supermassive black hole (SMBH) and a central accretion disk (AD). The dissipative force acting on stars in the disk leads to an enhanced mass flow toward the SMBH and to an asymmetry in the phase space distribution due to the rotating AD. The AD is considered as a stationary Keplerian rotating disk, which is vertically extended in order to employ a fully self-consistent treatment of stellar dynamics including the dissipative force originating from star-gas ram pressure effects. The stellar system is treated with a direct high-accuracy N-body integration code. A star-by-star representation, desirable in N-body simulations, cannot be extended to real particle numbers yet. Hence, we carefully discuss the scaling behavior of our model with regard to particle number and tidal accretion radius. The main idea is to find a family of models for which the ratio of two-body relaxation time and dissipation time (for kinetic energy of stellar orbits) is constant, which then allows us to extrapolate our results to real parameters of galactic nuclei. Our model is derived from basic physical principles and as such it provides insight into the role of physical processes in galactic nuclei, but it should be regarded as a first step toward more realistic and more comprehensive simulations. Nevertheless, the following conclusions appear to be robust: the star accretion rate onto the AD and subsequently onto the SMBH is enhanced by a significant factor compared to purely stellar dynamical systems neglecting the disk. This process leads to enhanced fueling of central disks in active galactic nuclei (AGNs) and to an enhanced rate of tidal stellar disruptions. Such disruptions may produce electromagnetic counterparts in the form of observable X-ray flares. Our models improve predictions for their rates in quiescent galactic nuclei. We do not yet model direct stellar collisions in the gravitational potential well of the black hole, which could further enhance the growth rate of the black hole. Our models are relevant for quiescent galactic nuclei, because all our mass accretion rates would give rise to luminosities much smaller than the Eddington luminosity. To reach Eddington luminosities, outflows, and feedback as in the most active QSOs, other scenarios are needed, such as gas accretion after galaxy mergers. However, for AGNs close to the Eddington limit, this process may not serve as the dominant accretion process due to the long timescale.

  7. Competition of different coupling schemes in atomic nuclei

    E-Print Network [OSTI]

    Qi, C; Wyss, R

    2012-01-01T23:59:59.000Z

    Shell model calculations reveal that the ground and low-lying yrast states of the $N=Z$ nuclei $^{92}_{46}$Pd and $^{96}$Cd are mainly built upon isoscalar spin-aligned neutron-proton pairs each carrying the maximum angular momentum J=9 allowed by the shell $0g_{9/2}$ which is dominant in this nuclear region. This mode of excitation is unique in nuclei and indicates that the spin-aligned pair has to be considered as an essential building block in nuclear structure calculations. In this contribution we will discuss this neutron-proton pair coupling scheme in detail. In particular, we will explore the competition between the normal monopole pair coupling and the spin-aligned coupling schemes. Such a coupling may be useful in elucidating the structure properties of $N=Z$ and neighboring nuclei.

  8. Competition of different coupling schemes in atomic nuclei

    E-Print Network [OSTI]

    C. Qi; R. J. Liotta; R. Wyss

    2012-02-17T23:59:59.000Z

    Shell model calculations reveal that the ground and low-lying yrast states of the $N=Z$ nuclei $^{92}_{46}$Pd and $^{96}$Cd are mainly built upon isoscalar spin-aligned neutron-proton pairs each carrying the maximum angular momentum J=9 allowed by the shell $0g_{9/2}$ which is dominant in this nuclear region. This mode of excitation is unique in nuclei and indicates that the spin-aligned pair has to be considered as an essential building block in nuclear structure calculations. In this contribution we will discuss this neutron-proton pair coupling scheme in detail. In particular, we will explore the competition between the normal monopole pair coupling and the spin-aligned coupling schemes. Such a coupling may be useful in elucidating the structure properties of $N=Z$ and neighboring nuclei.

  9. Formation of superheavy nuclei in cold fusion reactions

    E-Print Network [OSTI]

    Zhao-Qing Feng; Gen-Ming Jin; Jun-Qing Li; Werner Scheid

    2007-10-17T23:59:59.000Z

    Within the concept of the dinuclear system (DNS), a dynamical model is proposed for describing the formation of superheavy nuclei in complete fusion reactions by incorporating the coupling of the relative motion to the nucleon transfer process. The capture of two heavy colliding nuclei, the formation of the compound nucleus and the de-excitation process are calculated by using an empirical coupled channel model, solving a master equation numerically and applying statistical theory, respectively. Evaporation residue excitation functions in cold fusion reactions are investigated systematically and compared with available experimental data. Maximal production cross sections of superheavy nuclei in cold fusion reactions with stable neutron-rich projectiles are obtained. Isotopic trends in the production of the superheavy elements Z=110, 112, 114, 116, 118 and 120 are analyzed systematically. Optimal combinations and the corresponding excitation energies are proposed.

  10. Formation of superheavy nuclei in cold fusion reactions

    E-Print Network [OSTI]

    Feng, Zhao-Qing; Li, Jun-Qing; Scheid, Werner

    2007-01-01T23:59:59.000Z

    Within the concept of the dinuclear system (DNS), a dynamical model is proposed for describing the formation of superheavy nuclei in complete fusion reactions by incorporating the coupling of the relative motion to the nucleon transfer process. The capture of two heavy colliding nuclei, the formation of the compound nucleus and the de-excitation process are calculated by using an empirical coupled channel model, solving a master equation numerically and applying statistical theory, respectively. Evaporation residue excitation functions in cold fusion reactions are investigated systematically and compared with available experimental data. Maximal production cross sections of superheavy nuclei in cold fusion reactions with stable neutron-rich projectiles are obtained. Isotopic trends in the production of the superheavy elements Z=110, 112, 114, 116, 118 and 120 are analyzed systematically. Optimal combinations and the corresponding excitation energies are proposed.

  11. Structure of nuclei at extreme values of the isospin

    E-Print Network [OSTI]

    J. Dobaczewski

    1999-01-14T23:59:59.000Z

    Physics of nuclei at extreme values of the isospin is at the focus of present-day nuclear science. Experimentally, thanks to existing and emerging radioactive-ion-beam facilities, we are on the verge of invading the territory of extreme N/Z ratios in an unprecedented way. Theoretically, nuclear exotica represent a formidable challenge for the nuclear many-body theories and their power to predict nuclear properties far from stability. Going to the limits of the nuclear binding is also important for an improvement of our description of normal nuclei from the neighborhood of the beta stability valley. In the present talk, we review several aspects of the present-day mean-field theoretical studies of weakly bound nuclei.

  12. New description of the doublet bands in doubly odd nuclei

    SciTech Connect (OSTI)

    Ganev, H. G.; Georgieva, A. I. [Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Brant, S. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Ventura, A. [Ente per le Nuove tecnologie, l'Energia e l'Ambiente, I-40129 Bologna and Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy)

    2009-04-15T23:59:59.000Z

    The experimentally observed {delta}I=1 doublet bands in some odd-odd nuclei are analyzed within the orthosymplectic extension of the interacting vector boson model (IVBM). A new, purely collective interpretation of these bands is given on the basis of the obtained boson-fermion dynamical symmetry of the model. It is illustrated by its application to three odd-odd nuclei from the A{approx}130 region, namely {sup 126}Pr, {sup 134}Pr, and {sup 132}La. The theoretical predictions for the energy levels of the doublet bands as well as E2 and M1 transition probabilities between the states of the yrast band in the last two nuclei are compared with experiment and the results of other theoretical approaches. The obtained results reveal the applicability of the orthosymplectic extension of the IVBM.

  13. Validation of the MCNPX-PoliMi Code to Design a Fast-Neutron Multiplicity Counter

    SciTech Connect (OSTI)

    J. L. Dolan; A. C. Kaplan; M. Flaska; S. A. Pozzi; D. L. Chichester

    2012-07-01T23:59:59.000Z

    Many safeguards measurement systems used at nuclear facilities, both domestically and internationally, rely on He-3 detectors and well established mathematical equations to interpret coincidence and multiplicity-type measurements for verifying quantities of special nuclear material. Due to resource shortages alternatives to these existing He-3 based systems are being sought. Work is also underway to broaden the capabilities of these types of measurement systems in order to improve current multiplicity analysis techniques. As a part of a Material Protection, Accounting, and Control Technology (MPACT) project within the U.S. Department of Energy's Fuel Cycle Technology Program we are designing a fast-neutron multiplicity counter with organic liquid scintillators to quantify important quantities such as plutonium mass. We are also examining the potential benefits of using fast-neutron detectors for multiplicity analysis of advanced fuels in comparison with He-3 detectors and testing the performance of such designs. The designs are being developed and optimized using the MCNPX-PoliMi transport code to study detector response. In the full paper, we will discuss validation measurements used to justify the use of the MCNPX-PoliMi code paired with the MPPost multiplicity routine to design a fast neutron multiplicity counter with liquid scintillators. This multiplicity counter will be designed with the end goal of safeguarding advanced nuclear fuels. With improved timing qualities associated with liquid scintillation detectors, we can design a system that is less limited by nuclear materials of high activities. Initial testing of the designed system with nuclear fuels will take place at Idaho National Laboratory in a later stage of this collaboration.

  14. Development and commissioning of the Timing Counter for the MEG Experiment

    E-Print Network [OSTI]

    M. De Gerone; S. Dussoni; K. Fratini; F. Gatti; R. Valle; G. Boca; P. W. Cattaneo; R. Nardň; M. Rossella; L. Galli; M. Grassi; D. Nicolň; Y. Uchiyama; D. Zanello

    2012-02-04T23:59:59.000Z

    The Timing Counter of the MEG (Mu to Electron Gamma) experiment is designed to deliver trigger information and to accurately measure the timing of the $e^+$ in searching for the decay $\\mu^+ \\rightarrow e^+\\gamma$. It is part of a magnetic spectrometer with the $\\mu^+$ decay target in the center. It consists of two sectors upstream and downstream the target, each one with two layers: the inner one made with scintillating fibers read out by APDs for trigger and track reconstruction, the outer one consisting in scintillating bars read out by PMTs for trigger and time measurement. The design criteria, the obtained performances and the commissioning of the detector are presented herein.

  15. Dispersion equation for water waves with vorticity and Stokes waves on flows with counter-currents

    E-Print Network [OSTI]

    Vladimir Kozlov; Nikolay Kuznetsov

    2014-06-05T23:59:59.000Z

    The two-dimensional free-boundary problem of steady periodic waves with vorticity is considered for water of finite depth. We investigate how flows with small-amplitude Stokes waves on the free surface bifurcate from a horizontal parallel shear flow in which counter-currents may be present. Two bifurcation mechanisms are described: for waves with fixed Bernoulli's constant and fixed wavelength. In both cases the corresponding dispersion equations serve for defining wavelengths from which Stokes waves bifurcate. Sufficient conditions guaranteeing the existence of roots of these equations are obtained. Two particular vorticity distributions are considered in order to illustrate general results.

  16. Technical manual, redesigned ARC-2A automatic radon counter. Final report

    SciTech Connect (OSTI)

    Littfin, K.M.

    1992-09-01T23:59:59.000Z

    The ARC-2A Automatic Radon Counter (Serial No. 87003) was manufactured in 1987 by Ocean Communication Systems, Inc, Panama City, Florida. It was designed as a stand-alone system, but was consistently plagued with problems. The manufacturer could not repair the machine. The ARC-2A was completely redesigned at NCCOSC RDT and E Division. It is now interfaced to a computer. A new manual was written with updated information and user instructions. The ARC-2A is an integral part of ongoing electro-optic propagation studies.... Radon, Electro-optics, Aerosol.

  17. Anisotropic Power-law Inflation: A counter example to the cosmic no-hair conjecture

    E-Print Network [OSTI]

    Jiro Soda

    2014-10-31T23:59:59.000Z

    It is widely believed that anisotropy in the expansion of the universe will decay exponentially fast during inflation. This is often referred to as the cosmic no-hair conjecture. However, we find a counter example to the cosmic no-hair conjecture in the context of supergravity. As a demonstration, we present an exact anisotropic power-law inflationary solution which is an attractor in the phase space. We emphasize that anisotropic inflation is quite generic in the presence of anisotropic sources which couple with an inflaton.

  18. Exotic modes of excitation in proton rich nuclei

    SciTech Connect (OSTI)

    Paar, N. [Physics Department, Faculty of Science, University of Zagreb (Croatia)

    2011-11-30T23:59:59.000Z

    The framework of relativistic energy density functional has been applied in description of excitation phenomena in nuclei close to the proton drip line. In particular, low-lying dipole excitations have been studied using relativistic quasiparticle random phase approximation, based on effective Lagrangians with density dependent meson nucleon couplings. In the isovector dipole channel, the occurrence of pronounced low-lying dipole peaks is predicted, corresponding to the proton pygmy dipole resonance. Since this exotic mode still awaits its experimental confirmation, systematic calculations have been conducted within a pool of neutron deficient nuclei, in order to identify the best possible candidates for measurements.

  19. Proton and Neutron Momentum Distributions in A = 3 Asymmetric Nuclei

    E-Print Network [OSTI]

    O. Hen; L. B. Weinstein; S. Gilad; W. Boeglin

    2014-10-16T23:59:59.000Z

    A proposal approved by the Jefferson Lab (JLab) PAC to study the proton-to-neutron momentum distribution ratio in A=3 nuclei via (e,e'p) scattering off 3He and 3H mirror nuclei. The experiment will measure the 3H(e,e'p) and 3He(e,e'p) cross-sections and cross-section ratios at Q2 = 2 and xB>1 kinematics, over a missing momentum range of 0 - 450 MeV/c. The experiment was approved in 2014 at part of the JLab Hall-A Tritium run period for a total run time of 12 days.

  20. Systematics of nucleon density distributions and neutron skin of nuclei

    E-Print Network [OSTI]

    Seif, W M

    2015-01-01T23:59:59.000Z

    Proton and neutron density profiles of 760 nuclei in the mass region of A=16-304are analyzed using the Skyrme energy density for the parameter set SLy4. Simple formulae are obtained to fit the resulting radii and diffuseness data. These formulae may be useful to estimate the values of the unmeasured radii, and especially in extrapolating charge radius values for nuclei which are far from the valley of stability or to perform analytic calculations for bound and/or scattering problems. The obtained neutron and proton root-mean-square radii and the neutron skin thicknesses are in agreement with the available experimental data.

  1. JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei

    SciTech Connect (OSTI)

    Papenbrock, Thomas

    2014-05-16T23:59:59.000Z

    The grant “JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei ” (DOE DE?FG02?06ER41407) ran from 02/01/2006 thru 12/31/2013. JUSTIPEN is a venue for international collaboration between U.S.?based and Japanese scientists who share an interest in theory of rare isotopes. Since its inception JUSTIPEN has supported many visitors, fostered collaborations between physicists in the U.S. and Japan, and enabled them to deepen our understanding of exotic nuclei and their role in cosmos.

  2. Solar neutrino physics: Sensitivity to light dark matter particles

    E-Print Network [OSTI]

    Ilidio Lopes; Joseph Silk

    2013-09-29T23:59:59.000Z

    Neutrinos are produced in several neutrino nuclear reactions of the proton-proton chain and carbon-nitrogen-oxygen cycle that take place at different radius of the Sun's core. Hence, measurements of solar neutrino fluxes provide a precise determination of the local temperature. The accumulation of non-annihilating light dark matter particles (with masses between 5 GeV and 16 GeV in the Sun produces a change in the local solar structure, namely, a decrease in the central temperature of a few percent. This variation depends on the properties of the dark matter particles, such as the mass of the particle and its spin-independent scattering cross-section on baryon-nuclei, specifically, the scattering with helium, oxygen, and nitrogen among other heavy elements. This temperature effect can be measured in almost all solar neutrino fluxes. In particular, by comparing the neutrino fluxes generated by stellar models with current observations, namely 8B neutrino fluxes, we find that non-annihilating dark matter particles with a mass smaller than 10 GeV and a spin-independent scattering cross-section with heavy baryon-nuclei larger than 3 x 10^{-37} cm^-2 produce a variation in the 8B neutrino fluxes that would be in conflict with current measurements.

  3. Characterization of particles entrained in the effluent gases of an 18-inch AFBC

    SciTech Connect (OSTI)

    Anderson, R.J.; Childers, E.E.; Chidester, G.E.

    1983-02-01T23:59:59.000Z

    This experimental investigation was directed at measurements of the mass loading and size distribution of the particles entrained in the effluent gases of the Morgantown Energy Technology Center (METC) 18-inch, atmospheric pressure fluidized-bed combustor (AFBC). This information was required to aid in the continuing characterization of the AFBC, and to assess the efficiency or performance of an associated cleanup device. The particle-laden flow from the AFBC was introduced into a prototype granular-bed filter (GBF) designed for hot gas cleanup. In order to assess the efficiency of the GBF for particle removal, the mass loading and size distribution of particles contained in the cleaned gas emerging from the GBF were also determined. The effluent gases exit the AFBC at a nominal 1500/sup 0/F and a heavy particle loading (>1 g/scm). These conditions represent a harsh sampling environment. Filter samples obtained by extractive sampling formed the basis of the experimental information. Gravimetric and Coulter counter analyses were performed on each sample to provide mass loading and particle size data, respectively. Mass loadings of particles, as determined from filter samples collected at the inlet and outlet of the GBF, indicated particle removal efficiencies of about 80%. No significant variation in the particle removal efficiency was observed. Analysis of collected particulate samples showed no significant preferential removal of particles as a function of particle size. 2 figs., 1 tab.

  4. Volumetric particle modeling

    E-Print Network [OSTI]

    Dingle, Brent Michael

    2007-09-17T23:59:59.000Z

    and the lifetime of each particle is infinite. 2.1.2 Growing Patterns Particle systems can also model static or instantaneous things. They have been used to model plants and fracture patterns [21, 22] as well as lightning, frost, ice or snowflakes [23... mixes with dirt particles to form mud particles................................................... 121 61 Mud drying and cracking............................................................................................... 122 62 Ice melting...

  5. Investigation of Rare Particle Production in High Energy Nuclear Collisions

    SciTech Connect (OSTI)

    None

    1999-09-02T23:59:59.000Z

    Our program is an investigation of the hadronization process through measurement of rare particle production in high energy nuclear interactions. Such collisions of heavy nuclei provide an environment similar in energy density to the conditions in the Big Bang. We are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. We have completed our physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. We have produced the electronics and software for the STAR trigger and will begin to use these tools to search for anti-nuclei and strange hadrons when RHIC turns on later this year.

  6. Risk assessment methodology applied to counter IED research & development portfolio prioritization

    SciTech Connect (OSTI)

    Shevitz, Daniel W [Los Alamos National Laboratory; O' Brien, David A [Los Alamos National Laboratory; Zerkle, David K [Los Alamos National Laboratory; Key, Brian P [Los Alamos National Laboratory; Chavez, Gregory M [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    In an effort to protect the United States from the ever increasing threat of domestic terrorism, the Department of Homeland Security, Science and Technology Directorate (DHS S&T), has significantly increased research activities to counter the terrorist use of explosives. More over, DHS S&T has established a robust Counter-Improvised Explosive Device (C-IED) Program to Deter, Predict, Detect, Defeat, and Mitigate this imminent threat to the Homeland. The DHS S&T portfolio is complicated and changing. In order to provide the ''best answer'' for the available resources, DHS S&T would like some ''risk based'' process for making funding decisions. There is a definite need for a methodology to compare very different types of technologies on a common basis. A methodology was developed that allows users to evaluate a new ''quad chart'' and rank it, compared to all other quad charts across S&T divisions. It couples a logic model with an evidential reasoning model using an Excel spreadsheet containing weights of the subjective merits of different technologies. The methodology produces an Excel spreadsheet containing the aggregate rankings of the different technologies. It uses Extensible Logic Modeling (ELM) for logic models combined with LANL software called INFTree for evidential reasoning.

  7. Calibration of an ultra-low-background proportional counter for measuring {sup 37}Ar

    SciTech Connect (OSTI)

    Seifert, A.; Aalseth, C. E.; Bonicalzi, R. M.; Bowyer, T. W.; Day, A. R.; Fuller, E. S.; Haas, D. A.; Hayes, J. C.; Hoppe, E. W.; Humble, P. H.; Keillor, M. E.; LaFerriere, B. D.; Mace, E. K.; McIntyre, J. I.; Merriman, J. H.; Miley, H. S.; Myers, A. W.; Orrell, J. L.; Overman, C. T.; Panisko, M. E. [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99352 (United States)] [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99352 (United States); and others

    2013-08-08T23:59:59.000Z

    An ultra-low-background proportional counter design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electro-chemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with {sup 14}C/{sup 3}H, age-dating of groundwater with {sup 39}Ar, and soil-gas assay for {sup 37}Ar to support On-Site Inspection (OSI). On-Site Inspection is a key component of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of {sup 37}Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of {sup 37}Ar samples over a broad range of proportional counter operating pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for {sup 37}Ar soil gas background studies.

  8. Neutrinos, Rare Isotopes of Exotic Nuclei and Nuclear Astrophysics

    E-Print Network [OSTI]

    A. B. Balantekin

    2014-10-21T23:59:59.000Z

    The connection between neutrino physics, nucleosynthesis of elements in astrophysical sites, laboratory measurements with rare exotic nuclei and astronomical observations is discussed. The key role played by neutrinos is emphasized and the close connection between neutrino physics and nucleosynthesis is highlighted.

  9. Mini-Proceedings of ECT Workshop "Strangeness in Nuclei"

    E-Print Network [OSTI]

    C. Curceanu; J. Zmeskal

    2011-04-11T23:59:59.000Z

    This workshop brought together international experts in the research area of strangeness in nuclei physics, working on theory as well as on experiments, to discuss the present status, to develop new methods of analysis and to have the opportunity for brainstorming towards future studies, going towards a deeper understanding of the hot topics in the low-energy QCD in the strangeness sector.

  10. Search for spontaneous muon emission from lead nuclei

    E-Print Network [OSTI]

    L. Arrabito; D. Autiero; E. Barbuto; C. Bozza; S. Cecchini; L. Consiglio; M. Cozzi; N. D'Ambrosio; Y. Declais; G. De Lellis; G. De Rosa; M. De Serio; D. Di Ferdinando; A. Di Giovanni; N. Di Marco; L. S. Esposito; G. Giacomelli; M. Giorgini; G. Grella; M. Hauger; M. Ieva; D. B. Ion; I. Janicsko; F. Juget; I. Laktineh; G. Mandrioli; S. Manzoor; A. Margiotta; P. Migliozzi; P. Monacelli; M. T. Muciaccia; L. Patrizii; C. Pistillo; V. Popa; G. Romano; G. Rosa; P. Royole-Degieux; S. Simone; M. Sioli; C. Sirignano; G. Sirri; G. Sorrentino; M. Spurio; V. Tioukov

    2005-08-05T23:59:59.000Z

    We describe a possible search for muonic radioactivity from lead nuclei using the base elements ("bricks" composed by lead and nuclear emulsion sheets) of the long-baseline OPERA neutrino experiment. We present the results of a Monte Carlo simulation concerning the expected event topologies and estimates of the background events. Using few bricks, we could reach a good sensitivity level.

  11. Fission Characteristics of Heavy Nuclei: Statics and Dynamics

    E-Print Network [OSTI]

    Birger B. Back

    1999-06-14T23:59:59.000Z

    This paper presents a selective historical perspective of fission research over the last thirty-five years while Ray Nix has made central contributions to the field. The emphasis is placed on early studies of the shell stabilized secondary minimum in the static fission barrier and on the dynamic properties of fission of hot nuclei, which have recently been the focus of intense study.

  12. Helium halo nuclei from low-momentum interactions

    E-Print Network [OSTI]

    S. Bacca; A. Schwenk; G. Hagen; T. Papenbrock

    2009-05-14T23:59:59.000Z

    We present ground-state energies of helium halo nuclei based on chiral low-momentum interactions, using the hyperspherical-harmonics method for 6He and coupled-cluster theory for 8He, with correct asymptotics for the extended halo structure.

  13. Folding model description of reactions with exotic nuclei

    SciTech Connect (OSTI)

    Ibraheem, Awad A., E-mail: awad_ah_eb@hotmail.com [Al-Azhar University, Assiut Branch, Physics Department (Egypt); Hassanain, M. A. [King Khalid University, Physics Department (Saudi Arabia); Mokhtar, S. R. [Assiut University, Physics Department (Egypt); Zaki, M. A. [South-Valley University, Physics Department (Egypt); Mahmoud, Zakaria M. M. [Assiut University, Sciences Department, New-Valley Faculty of Education (Egypt); Farid, M. El-Azab [Assiut University, Physics Department (Egypt)

    2012-08-15T23:59:59.000Z

    Microscopic folding calculations based upon the effective M3Y nucleon-nucleon interaction and the nuclearmatter densities of the interacting nuclei have been carried out to explain recently measured experimental data of the {sup 6}He+{sup 120}Sn elastic scattering cross section at four different laboratory energies near the Coulomb barrier. The extracted reaction cross sections are also considered.

  14. Coherent dissociation of relativistic {sup 12}N nuclei

    SciTech Connect (OSTI)

    Kattabekov, R. R.; Mamatkulov, K. Z. [Joint Institute for Nuclear Research (Russian Federation)] [Joint Institute for Nuclear Research (Russian Federation); Alikulov, S. S. [A. Kodirii Jizzakh State Pedagogical Institute (Uzbekistan)] [A. Kodirii Jizzakh State Pedagogical Institute (Uzbekistan); Artemenkov, D. A. [Joint Institute for Nuclear Research (Russian Federation)] [Joint Institute for Nuclear Research (Russian Federation); Bekmirzaev, R. N. [A. Kodirii Jizzakh State Pedagogical Institute (Uzbekistan)] [A. Kodirii Jizzakh State Pedagogical Institute (Uzbekistan); Bradnova, V.; Zarubin, P. I., E-mail: zarubin@lhe.jinr.ru; Zarubina, I. G.; Kondratieva, N. V.; Kornegrutsa, N. K.; Krivenkov, D. O.; Malakhov, A. I. [Joint Institute for Nuclear Research (Russian Federation)] [Joint Institute for Nuclear Research (Russian Federation); Olimov, K. [Uzbek Academy of Sciences, Institute for Physics and Technology (Uzbekistan)] [Uzbek Academy of Sciences, Institute for Physics and Technology (Uzbekistan); Peresadko, N. G.; Polukhina, N. G. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)] [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Rukoyatkin, P. A.; Rusakova, V. V.; Stanoeva, R. [Joint Institute for Nuclear Research (Russian Federation)] [Joint Institute for Nuclear Research (Russian Federation); Kharlamov, S. P. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)] [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2013-10-15T23:59:59.000Z

    The dissociation of relativistic {sup 12}N nuclei having a momentum of 2 GeV/c per nucleon and undergoing the most peripheral interactions in a track emulsion is studied. The picture of charged topology of product ensembles of relativistic fragments and special features of their angular distributions are presented.

  15. Clusters and halos in light nuclei

    E-Print Network [OSTI]

    Thomas Neff

    2012-10-15T23:59:59.000Z

    The fermionic molecular dynamics approach uses Gaussian wave packets as single-particle basis states. Many-body basis states are Slater determinants projected on parity, angular momentum and total linear momentum. The wave-packet basis is very flexible - FMD contains harmonic oscillator shell model and Brink-type cluster states as special cases. The parameters of the wave packets are obtained by variation. A realistic effective interaction derived from the Argonne V18 interaction by means of the unitary correlation operator method is employed. We discuss the fully microscopic calculation of the 3He(alpha,gamma)7Be capture reaction within the FMD approach. The model space contains frozen cluster configurations at large distances and polarized configurations in the interaction region. The polarized configurations are essential for a successful description of the 7Be bound state properties and for the S- and D-wave scattering states. The calculated cross section agrees well with recent measurements regarding both the absolute normalization and the energy dependence. We also discuss the structure of the cluster states, including the famous Hoyle state, in 12C. From the two-body densities we conclude that the Hoyle state has a spatially extended triangular alpha-cluster structure, whereas the third 0+ state features a chain-like obtuse triangle structure. We also calculate the N hbar Omega decomposition of our wave functions to illuminate the challenges of no-core shell model calculations for these cluster states.

  16. Modelling Counter-Current Two-Phase Flow of Saturated Superfluid Helium in Quasi-Horizontal Tubes: Application to the LHC Cryogenic System

    E-Print Network [OSTI]

    Guinaudeau, H

    1996-01-01T23:59:59.000Z

    Modelling Counter-Current Two-Phase Flow of Saturated Superfluid Helium in Quasi-Horizontal Tubes: Application to the LHC Cryogenic System

  17. New measurements of high-momentum nucleons and short-range structures in nuclei

    E-Print Network [OSTI]

    N. Fomin; J. Arrington; R. Asaturyan; F. Benmokhtar; W. Boeglin; P. Bosted; A. Bruell; M. H. S. Bukhari; E. Chudakov; B. Clasie; S. H. Connell; M. M. Dalton; A. Daniel; D. B. Day; D. Dutta; R. Ent; L. El Fassi; H. Fenker; B. W. Filippone; K. Garrow; D. Gaskell; C. Hill; R. J. Holt; T. Horn; M. K. Jones; J. Jourdan; N. Kalantarians; C. E. Keppel; D. Kiselev; M. Kotulla; R. Lindgren; A. F. Lung; S. Malace; P. Markowitz; P. McKee; D. G. Meekins; H. Mkrtchyan; T. Navasardyan; G. Niculescu; A. K. Opper; C. Perdrisat; D. H. Potterveld; V. Punjabi; X. Qian; P. E. Reimer; J. Roche; V. M. Rodriguez; O. Rondon; E. Schulte; J. Seely; E. Segbefia; K. Slifer; G. R. Smith; P. Solvignon; V. Tadevosyan; S. Tajima; L. Tang; G. Testa; R. Trojer; V. Tvaskis; W. F. Vulcan; C. Wasko; F. R. Wesselmann; S. A. Wood; J. Wright; X. Zheng

    2012-01-10T23:59:59.000Z

    We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

  18. Spin-dependent scattering and absorption of thermal neutrons on dynamically polarized nuclei

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    957 Spin-dependent scattering and absorption of thermal neutrons on dynamically polarized nuclei H neutrons and polarized nuclei have been used to measure spin-dependent scattering lengths and absorption cross sections of slow (S-wave) neutrons on nuclei. In order to obtain those scattering lengths

  19. Effect of Nuclei Concentration on Cavitation Cluster Dynamics C.D. Ohl, and D. Lohse

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    Effect of Nuclei Concentration on Cavitation Cluster Dynamics M. Arora, C.D. Ohl, and D. Lohse, The Netherlands. (Dated: July 2, 2007) 1 #12;Abstract Cavitation cluster dynamics after the passage of a single pressure wave is studied for different concentrations of artificial cavitation nuclei (30 to 3·105 nuclei

  20. Microscopic description of neutron emission rates in compound nuclei

    E-Print Network [OSTI]

    Yi Zhu; Junchen Pei

    2014-11-02T23:59:59.000Z

    The neutron emission rates in thermal excited nuclei are conventionally described by statistical models with a phenomenological level density parameter that depends on excitation energies, deformations and mass regions. In the microscopic view of hot nuclei, the neutron emission rates can be determined by the external neutron gas densities without any free parameters. Therefore the microscopic description of thermal neutron emissions is desirable that can impact several understandings such as survival probabilities of superheavy compound nuclei and neutron emissivity in reactors. To describe the neutron emission rates microscopically, the external thermal neutron gases are self-consistently obtained based on the Finite-Temperature Hartree-Fock-Bogoliubov (FT-HFB) approach. The results are compared with the statistical model to explore the connections between the FT-HFB approach and the statistical model. The Skyrme FT-HFB equation is solved by HFB-AX in deformed coordinate spaces. Based on the FT-HFB approach, the thermal properties and external neutron gas are properly described with the self-consistent gas substraction procedure. Then neutron emission rates can be obtained based on the densities of external neutron gases. The thermal statistical properties of $^{238}$U and $^{258}$U are studied in detail in terms of excitation energies. The thermal neutron emission rates in $^{238, 258}$U and superheavy compound nuclei $_{112}^{278}$Cn and $_{114}^{292}$Fl are calculated, which agree well with the statistical model by adopting an excitation-energy-dependent level density parameter. The coordinate-space FT-HFB approach can provide reliable microscopic descriptions of neutron emission rates in hot nuclei, as well as microscopic constraints on the excitation energy dependence of level density parameters for statistical models.

  1. (Medium energy particle physics): Annual progress report

    SciTech Connect (OSTI)

    Nefkens, B.M.K.

    1985-10-01T23:59:59.000Z

    Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of /sup 3/H, /sup 3/He, /sup 4/He; Detailed Balance in pd /r reversible/ /gamma//sup 3/H; Interaction Dynamics); and Search for the Rare Decay /Mu//sup +/ /yields/ e/sup +/ + /gamma/ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects.

  2. The Role of Density Dependent One-Body Momentum Distribution on the Calculation of Ground State Properties of Closed Shell Nuclei

    E-Print Network [OSTI]

    Mariji, Hodjat

    2015-01-01T23:59:59.000Z

    Constructing the density-dependent one-body momentum distribution (DDOBMD) functions and the density-momentum dependent single particle potential (DMDSPP) from the calculations of the LOCV method for the symmetric nuclear matter with the $A\\upsilon_{18}$ potential, the role of the DDOBMD functions on the calculation of the ground-state properties of closed shell nuclei, i.e., $^{16}O$, $^{40}Ca$ and $^{56}Ni$, is investigated. Since the contribution of partial waves with $J_{max} > 2$ are not very significant relative to those of $J_{max} \\leq 2$ on the calculation of the DDOBMD function and the DMDSPP, as shown by including the $A\\upsilon_{18}(J_{max}=5)$ potential, the investigation of the DDOBMD role on the major single particle levels (SPLs) and the nuclei binding energies are studied by the $A\\upsilon_{18}(J_{max}=2)$ potential. The best fit of spin-orbit splitting is taken into account when correcting the major SPLs of the nuclei at the minimum point of energy (MPE) by means of the new parameterized Woo...

  3. A practical scheme for generating isolated elliptically polarized attosecond pulses using bi-chromatic counter rotating circularly polarized laser fields

    E-Print Network [OSTI]

    Medišauskas, Lukas; van der Haart, Hugo; Ivanov, Misha Yu

    2015-01-01T23:59:59.000Z

    Spectra of circularly polarized harmonics is calculated by numerically solving the Time-Dependent Schr\\"{o}dinger Equation for a 2D model of Ne atom using circularly polarized fundamental with counter-rotating second harmonic laser fields. We demonstrate strong asymmetry between left- and right- circularly polarized harmonics when a ground state with p-type symmetry is used. It arises due to the circular polarization of individual attosecond pulses in the generated pulse train. Reducing the length of the counter-rotating drivers and introducing a small time-shift between them allows to generate a single elliptically polarized attosecond pulse.

  4. Energy and Mass Dependences of the Parameters of the Semimicroscopic Folding Model for Alpha Particles at Low and Intermediate Energies

    SciTech Connect (OSTI)

    Kuterbekov, K.A.; Zholdybayev, T.K. [Institute of Nuclear Physics, National Nuclear Center of the Republic of Kazakhstan, Almaty, 480082 (Kazakhstan); Kukhtina, I.N.; Penionzhkevich, Yu.E. [Joint Institute for Nuclear Research, Dubna, Moscow oblast, 141980 (Russian Federation)

    2005-06-01T23:59:59.000Z

    The energy and mass dependences of the parameters of the semimicroscopic alpha-particle potential are investigated for the first time in the region of low and intermediate energies. Within the semimicroscopic folding model, both elastic and inelastic differential and total cross sections for reactions on various nuclei are well described by using global parameters obtained in this study.

  5. Volcanic particle aggregation in explosive eruption columns. Part I: Parameterization of the microphysics of hydrometeors and ash

    E-Print Network [OSTI]

    Rose, William I.

    , Michigan Technological University, Houghton, MI, USA d Department of Earth Sciences, University of Bristol imply that volcanic particles are active as condensation nuclei for water and ice formation. Ash can: Department of Geography, University of Cambridge, UK. 2 Present address: NOAA Geophysical Fluid Dynamics

  6. Particle acceleration and radiation friction effects in the filamentation instability of pair plasmas

    E-Print Network [OSTI]

    D'Angelo, M; Sgattoni, A; Pegoraro, F; Macchi, A

    2015-01-01T23:59:59.000Z

    The evolution of the filamentation instability produced by two counter-streaming pair plasmas is studied with particle-in-cell (PIC) simulations in both one (1D) and two (2D) spatial dimensions. Radiation friction effects on particles are taken into account. After an exponential growth of both the magnetic field and the current density, a nonlinear quasi-stationary phase sets up characterized by filaments of opposite currents. During the nonlinear stage, a strong broadening of the particle energy spectrum occurs accompanied by the formation of a peak at twice their initial energy. A simple theory of the peak formation is presented. The presence of radiative losses does not change the dynamics of the instability but affects the structure of the particle spectra.

  7. Methodology for the use of proportional counters in pulsed fast neutron yield measurements

    E-Print Network [OSTI]

    Tarifeńo-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo

    2011-01-01T23:59:59.000Z

    This paper introduces in full detail a methodology for the measurement of neutron yield and the necessary efficiency calibration, to be applied to the intensity measurement of neutron bursts where individual neutrons are not resolved in time, for any given moderated neutron proportional counter array. The method allows efficiency calibration employing the detection neutrons arising from an isotopic neutron source. Full statistical study of the procedure is descripted, taking into account contributions arising from counting statistics, piling-up statistics of real detector pulse-height spectra and background fluctuations. The useful information is extracted from the net waveform area of the signal arising from the electric charge accumulated inside the detector tube. Improvement of detection limit is gained, therefore this detection system can be used in detection of low emission neutron pulsed sources with pulses of duration from nanoseconds to up. The application of the methodology to detection systems to be...

  8. Coherent Control of Resonant Two-Photon Transitions by Counter-Propagating Ultrashort Pulse Pairs

    E-Print Network [OSTI]

    Lee, Woojun; Kim, Kyungtae; Ahn, Jaewook

    2015-01-01T23:59:59.000Z

    We describe optimized coherent control methods for two-photon transitions in atoms of a ladder-type three-state energy configuration. Our approach is based on the spatial coherent control scheme which utilizes counter-propagating ultrashort laser pulses to produce complex excitation patterns in an extended space. Since coherent control requires constructive interference of constituent transition pathways, applying it to an atomic transition with a specific energy configuration requires specially designed laser pulses. Here, we show, in an experimental demonstration, that the two-photon transition with an intermediate resonant energy state can be coherently controlled and retrieved out from the resonance-induced background, when phase-flipping of the laser spectrum near the resonant intermediate transition is used. A simple reason for this behavior is the fact that the transition amplitude function (to be added to give an overall two-photon transition) changes its sign at the intermediate resonant frequency, t...

  9. Opposite charged two-body system of identical counter-rotating black holes

    E-Print Network [OSTI]

    I. Cabrera-Munguia; Claus Lämmerzahl; L. A. López; Alfredo Macías

    2014-05-12T23:59:59.000Z

    A 4-parametric exact solution describing a two-body system of identical Kerr-Newman counter-rotating black holes endowed with opposite electric/magnetic charges is presented. The axis conditions are solved in order to really describe two black holes separated by a massless strut. Moreover, the explicit form of the horizon half length parameter sigma in terms of physical Komar parameters, i.e., the Komar mass M, electric charge QE, angular momentum J, and a coordinate distance R is derived. Additionally, magnetic charges QB arise from the rotation of electrically charged black holes. As a consequence, in order to account for the contribution to the mass of the magnetic charge, the usual Smarr mass formula should be generalized, as it is proposed by A. Tomimatsu, Prog. Theor. Phys. 72, 73 (1984).

  10. The underwater coincidence counter for plutonium measurements in mixed-oxide fuel assemblies manual

    SciTech Connect (OSTI)

    G. W. Eccleston; H. O. Menlove; M. Abhold; M. Baker; J. Pecos

    1999-05-01T23:59:59.000Z

    This manual describes the Underwater Coincidence Counter (UWCC) that has been designed for the measurement of plutonium in mixed-oxide (MOX) fuel assemblies prior to irradiation. The UWCC uses high-efficiency {sup 3}He neutron detectors to measure the spontaneous-fission and induced-fission rates in the fuel assembly. Measurements can be made on MOX fuel assemblies in air or underwater. The neutron counting rate is analyzed for singles, doubles, and triples time correlations to determine the {sup 240}Pu effective mass per unit length of the fuel assembly. The system can verify the plutonium loading per unit length to a precision of less than 1% in a measurement time of 2 to 3 minutes. System design, components, performance tests, and operational characteristics are described in this manual.

  11. Single-photon detection timing jitter in a visible light photon counter

    E-Print Network [OSTI]

    Burm Baek; Kyle S. McKay; Martin J. Stevens; Jungsang Kim; Henry H. Hogue; Sae Woo Nam

    2010-01-27T23:59:59.000Z

    Visible light photon counters (VLPCs) offer many attractive features as photon detectors, such as high quantum efficiency and photon number resolution. We report measurements of the single-photon timing jitter in a VLPC, a critical performance factor in a time-correlated single-photon counting measurement, in a fiber-coupled closed-cycle cryocooler. The measured timing jitter is 240 ps full-width-at-half-maximum at a wavelength of 550 nm, with a dark count rate of 25 000 counts per second. The timing jitter increases modestly at longer wavelengths to 300 ps at 1000 nm, and increases substantially at lower bias voltages as the quantum efficiency is reduced.

  12. Characterization of novel Hamamatsu Multi Pixel Photon Counter (MPPC) arrays for the GlueX experiment

    SciTech Connect (OSTI)

    Soto, Orlando [Universidad T?cnica Federico Santa Mar?a; Rojas, Rimsky [Universidad T?cnica Federico Santa Mar?a; Kuleshov, Sergey V. [Universidad T?cnica Federico Santa Mar?a; Hakobyan, Hayk [Universidad T?cnica Federico Santa Mar?a; Toro, Alam [Universidad T?cnica Federico Santa Mar?a; Brooks, William K. [Universidad T?cnica Federico Santa Mar?a

    2013-12-01T23:59:59.000Z

    The novel Hamamatsu Multi Pixel Photon Counter Array S12045(X) is an array of 16 individual MPPCs (3x3 mm{sup 2}) (further in the paper MPPC array channel) each with 3600 G-APD (Geiger-mode Avalanche Photodiodes) pixels (50x50 [{micro}m{sup 2}]). Each MPPC in the array works with its individual reverse bias voltage mode (around 70 V). The paper summarizes the characterization process of MPPC arrays used in GlueX experiment (Hall D, Jefferson Lab). We studied the main features of each MPPC array channel for 2800 MPPC arrays at different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photo detection efficiency (PDE), optical crosstalk and dark rate for each MPPC array channel. The hardware and the data analysis are described, which includes new analytical expressions to obtain the mean number of photo-electrons and optical crosstalk. The dynamical behavior of characterization parameters is presented as well.

  13. Electrochemical sensor having suspended element counter electrode and deflection method for current sensing

    DOE Patents [OSTI]

    Thundat, Thomas G.; Brown, Gilbert M.

    2010-05-18T23:59:59.000Z

    An electrochemical suspended element-based sensor system includes a solution cell for holding an electrolyte comprising solution including at least one electrochemically reducible or oxidizable species. A working electrode (WE), reference electrode (RE) and a counter electrode (CE) are disposed in the solution. The CE includes an asymmetric suspended element, wherein one side of the suspended element includes a metal or a highly doped semiconductor surface. The suspended element bends when current associated with reduction or oxidation of the electrochemically reducible or oxidizable species at the WE passes through the suspended element. At least one measurement system measures the bending of the suspended element or a parameter which is a function of the bending.

  14. Scintillation counter and wire chamber front end modules for high energy physics experiments

    SciTech Connect (OSTI)

    Baldin, Boris; DalMonte, Lou; /Fermilab

    2011-01-01T23:59:59.000Z

    This document describes two front-end modules developed for the proposed MIPP upgrade (P-960) experiment at Fermilab. The scintillation counter module was developed for the Plastic Ball detector time and charge measurements. The module has eight LEMO 00 input connectors terminated with 50 ohms and accepts negative photomultiplier signals in the range 0.25...1000 pC with the maximum input voltage of 4.0 V. Each input has a passive splitter with integration and differentiation times of {approx}20 ns. The integrated portion of the signal is digitized at 26.55 MHz by Analog Devices AD9229 12-bit pipelined 4-channel ADC. The differentiated signal is discriminated for time measurement and sent to one of the four TMC304 inputs. The 4-channel TMC304 chip allows high precision time measurement of rising and falling edges with {approx}100 ps resolution and has internal digital pipeline. The ADC data is also pipelined which allows deadtime-less operation with trigger decision times of {approx}4 {micro}s. The wire chamber module was developed for MIPP EMCal detector charge measurements. The 32-channel digitizer accepts differential analog signals from four 8-channel integrating wire amplifiers. The connection between wire amplifier and digitizer is provided via 26-wire twist-n-flat cable. The wire amplifier integrates input wire current and has sensitivity of 275 mV/pC and the noise level of {approx}0.013 pC. The digitizer uses the same 12-bit AD9229 ADC chip as the scintillator counter module. The wire amplifier has a built-in test pulser with a mask register to provide testing of the individual channels. Both modules are implemented as a 6Ux220 mm VME size board with 48-pin power connector. A custom europack (VME) 21-slot crate is developed for housing these front-end modules.

  15. A Single Tower Configuration of the Modular Gamma Box Counter System - 13392

    SciTech Connect (OSTI)

    Morris, K.; Nakazawa, D.; Francalangia, J.; Gonzalez, H. [Canberra Industries Inc., 800 Research Parkway, Meriden, CT, 06450 (United States)] [Canberra Industries Inc., 800 Research Parkway, Meriden, CT, 06450 (United States)

    2013-07-01T23:59:59.000Z

    Canberra's Standard Gamma Box Counter System is designed to perform accurate quantitative assays of gamma emitting nuclides for a wide range of large containers including B-25 crates and ISO shipping containers. Using a modular building-block approach, the system offers tremendous flexibility for a variety of measurement situations with wide ranges of sample activities and throughput requirements, as well as the opportunity to modify the configuration for other applications at a later date. The typical configuration consists of two opposing towers each equipped with two high purity germanium detectors, and an automated container trolley. This paper presents a modified configuration, consisting of a single tower placed inside a measurement trailer with three detector assemblies, allowing for additional vertical segmentation as well as a viewing a container outside the trailer through the trailer wall. An automatic liquid nitrogen fill system is supplied for each of the detectors. The use of a forklift to move the container for horizontal segmentation is accommodated by creating an additional operational and calibration set-up in the NDA 2000 software to allow for the operator to rotate the container and assay the opposite side, achieving the same sensitivity as a comparable two-tower system. This Segmented Gamma Box Counter System retains the core technologies and design features of the standard configuration. The detector assemblies are shielded to minimize interference from environmental and plant background, and are collimated to provide segmentation of the container. The assembly positions can also be modified in height and distance from the container. The ISOCS calibration software provides for a flexible approach to providing the calibrations for a variety of measurement geometries. The NDA 2000 software provides seamless operation with the current configuration, handling the data acquisition and analysis. In this paper, an overview of this system is discussed, along with the measured performance results, calibration methodology and verification, and minimum detectable activity levels. (authors)

  16. RIKEN Review No. 23 (July, 1999): Focused on Selected Topics in Nuclear Collective Excitations How to go from finite nuclei to infinite nuclear matter

    E-Print Network [OSTI]

    Lakshmidhar Satpathy

    The traditional path of going from finite nuclei to infinite nuclear matter (INM) via Bethe-Weiszacker (BW) like mass formulas based on liquid drop model (LDM) is faulty and without strong theoretical basis. The defect is attributed to its use of liquid drop without any reference to particles as its basis, which is classical in nature. It does not possess an essential property of an interacting many-fermion system namely, the single particle property, in particular the Fermi state. In fact the volume term of such mass formulas does not corresspond to the ground state of INM. It is shown that, the defect is repaired in the infinite nuclear matter model by the use of generalized Hugenholtz-Van Hove theorem of many-body theory. This model uses infinite nuclear matter with well defined quantum mechanical attributes for its basis. The resulting expansion has the coefficients which are at the ground state of nuclear matter. It results into a successful mass formula for nuclei. Then using this model, the saturation density 0.1620 fm-3 and binding energy per nucleon of nuclear matter 16.108 MeV are determined from the masses of all known nuclei. The corresponding radius constant r0 equal to 1.138 fm thus determined, agrees quite well with that obtained from electron scattering data, leading to the resolution of the so-called ‘r0-paradox’. Finally a well defined and stable value of 288 20 MeV for the incompressibility of nuclear matter K1,is extracted from the same set of masses and a nuclear equation of state is thus obtained. Thus a well defined path from finite nuclei to nuclear matter is found out.

  17. Magnetic Moments of Light Nuclei from Lattice Quantum Chromodynamics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Beane, S. R.; Chang, E.; Cohen, S.; Detmold, W.; Lin, H W.; Orginos, K; Parreno, A; Savage, M J.; Tiburzi, B C.

    2014-12-01T23:59:59.000Z

    We present the results of lattice QCD calculations of the magnetic moments of the lightest nuclei, the deuteron, the triton and 3He, along with those of the neutron and proton. These calculations, performed at quark masses corresponding to m_pi ~ 800 MeV, reveal that the structure of these nuclei at unphysically heavy quark masses closely resembles that at the physical quark masses. In particular, we find that the magnetic moment of 3He differs only slightly from that of a free neutron, as is the case in nature, indicating that the shell-model configuration of two spin-paired protons and a valence neutronmore »captures its dominant structure. Similarly a shell-model-like moment is found for the triton, mu_^3H ~ mu_p. The deuteron magnetic moment is found to be equal to the nucleon isoscalar moment within the uncertainties of the calculations.« less

  18. Magnetic Moments of Light Nuclei from Lattice Quantum Chromodynamics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Beane, S. R.; Chang, E.; Cohen, S.; Detmold, W.; Lin, H W.; Orginos, K.; Parreno, A; Savage, M J.; Tiburzi, B C.

    2014-12-01T23:59:59.000Z

    We present the results of lattice QCD calculations of the magnetic moments of the lightest nuclei, the deuteron, the triton and 3He, along with those of the neutron and proton. These calculations, performed at quark masses corresponding to m_pi ~ 800 MeV, reveal that the structure of these nuclei at unphysically heavy quark masses closely resembles that at the physical quark masses. In particular, we find that the magnetic moment of 3He differs only slightly from that of a free neutron, as is the case in nature, indicating that the shell-model configuration of two spin-paired protons and a valence neutron captures its dominant structure. Similarly a shell-model-like moment is found for the triton, mu_^3H ~ mu_p. The deuteron magnetic moment is found to be equal to the nucleon isoscalar moment within the uncertainties of the calculations.

  19. The CLAS Start Counter S. Taylor a , S. Ahmad d , J. Distelbrink c , G. S. Mutchler a ,

    E-Print Network [OSTI]

    Thomas Jefferson National Accelerator Facility

    Overview of CLAS The Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Je#erson National Accelerator Facility currently delivers CW electron beam up to #6 GeV in energy. The machine can deliver B at the Thomas Je#erson National Accelerator Facility. The Start Counter is constructed of three 3

  20. Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind

    E-Print Network [OSTI]

    Dabiri, John O.

    Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical an alternative approach to wind farming that has the potential to concurrently reduce the cost, size-axis wind turbine arrays John O. Dabiria) Graduate Aeronautical Laboratories and Bioengineering, California

  1. Mid-Infrared Spectroscopic Diagnostics of Galactic Nuclei

    E-Print Network [OSTI]

    Vassilis Charmandaris; the Spitzer/IRS Instrument Team

    2006-07-13T23:59:59.000Z

    In this paper I summarize the science motivations, as well as a few mid-infrared spectroscopic methods used to identify the principal mechanisms of energy production in dust enshrouded galactic nuclei. The development of the various techniques is briefly discussed. Emphasis is given to the use of the data which are becoming available with the infrared spectrograph (IRS) on Spitzer, as well as the results which have been obtained by IRS over the past two years.

  2. Nuclear multifragmentation and phase transition for hot nuclei

    E-Print Network [OSTI]

    B. Borderie; M. F. Rivet

    2008-12-18T23:59:59.000Z

    This review article is focused on the tremendous progress realized during the last fifteen years in the understanding of multifragmentation and its relationship to the liquid-gas phase diagram of nuclei and nuclear matter. The explosion of the whole nucleus, early predicted by Bohr [N. Bohr, Nature 137 (1936) 351], is a very complex and rich subject which continues to fascinate nuclear physicists as well as theoreticians who extend the thermodynamics of phase transitions to finite systems.

  3. Energy density functional for nuclei and neutron stars

    E-Print Network [OSTI]

    J. Erler; C. J. Horowitz; W. Nazarewicz; M. Rafalski; P. -G. Reinhard

    2012-11-27T23:59:59.000Z

    We aim to develop a nuclear energy density functional that can be simultaneously applied to finite nuclei and neutron stars. We use the self-consistent nuclear density functional theory (DFT) with Skyrme energy density functionals and covariance analysis to assess correlations between observables for finite nuclei and neutron stars. In a first step two energy functionals -- a high density energy functional giving reasonable neutron properties, and a low density functional fitted to nuclear properties -- are matched. In a second step, we optimize a new functional using exactly the same protocol as in earlier studies pertaining to nuclei but now including neutron star data. This allows direct comparisons of performance of the new functional relative to the standard one. The new functional TOV-min yields results for nuclear bulk properties (energy, r.m.s. radius, diffraction radius, surface thickness) that are of the same quality as those obtained with the established Skyrme functionals, including SV-min. When comparing SV-min and TOV-min, isoscalar nuclear matter indicators vary slightly while isovector properties are changed considerably. We discuss neutron skins, dipole polarizability, separation energies of the heaviest elements, and proton and neutron drip lines. We confirm a correlation between the neutron skin of $^{208}$Pb and the neutron star radius. We demonstrate that standard energy density functionals optimized to nuclear data do not carry information on the expected maximum neutron star mass, and that predictions can only be made within an extremely broad uncertainty band. For atomic nuclei, the new functional TOV-min performs at least as well as the standard nuclear functionals, but it also reproduces expected neutron star data within assumed error bands.

  4. Production of $?$ and $?'$ Mesons on Nucleons and Nuclei

    E-Print Network [OSTI]

    B. Krusche; C. Wilkin

    2014-10-28T23:59:59.000Z

    The production of $\\eta$ and $\\eta^{\\prime}$ mesons in photon- and hadron-induced reactions on free and quasi-free nucleons and on nuclei is reviewed. The extensive database on $\\gamma N \\to \\eta N$, for both proton and neutron targets, is described in detail and its implications for the search for $N^{\\star}$ resonances much heavier than the dominant $S_{11}(1535)$ discussed. Though less is currently known about the production of the $\\eta^{\\prime}$ or of $\\eta\\pi$ pairs, these also offer tantalizing prospects in the search for the missing isobars. The more limited data available on pion-induced production are still necessary ingredients in the partial wave analysis discussed. The production of the $\\eta$-meson in $pp$ and $pn$ collisions shows once again the strong influence of the $S_{11}(1535)$ isobar, which is in contrast to the relatively weak behaviour seen near threshold for $\\eta^{\\prime}$ production. This difference is reflected in the important final state interaction effects of the $\\eta$ in nuclei that may even lead to this meson being "bound" in some systems. The evidence for this is reviewed for both $\\gamma A$ and $p A$ collisions. The inclusive photoproduction of $\\eta$, $\\eta^{\\prime}$, and $\\eta\\pi$ pairs from nuclei provides further information regarding the production mechanism and the interaction of the $\\eta$ and $\\eta^{\\prime}$ with nuclei and the $\\eta\\pi$ pairs may even allow access to low mass $\\eta A$ systems that are forbidden in direct single-meson photoproduction.

  5. Density dependence of symmetry free energy of hot nuclei

    E-Print Network [OSTI]

    S. K. Samaddar; J. N. De; X. Vinas; M. Centelles

    2008-09-04T23:59:59.000Z

    The density and excitation energy dependence of symmetry energy and symmetry free energy for finite nuclei are calculated microscopically in a microcanonical framework taking into account thermal and expansion effects. A finite-range momentum and density dependent two-body effective interaction is employed for this purpose. The role of mass, isospin and equation of state (EoS) on these quantities is also investigated; our calculated results are in consonance with the available experimental data.

  6. Density matrix renormalization group and wave function factorization for nuclei

    E-Print Network [OSTI]

    T. Papenbrock; D. J. Dean

    2005-07-15T23:59:59.000Z

    We employ the density matrix renormalization group (DMRG) and the wave function factorization method for the numerical solution of large scale nuclear structure problems. The DMRG exhibits an improved convergence for problems with realistic interactions due to the implementation of the finite algorithm. The wave function factorization of fpg-shell nuclei yields rapidly converging approximations that are at the present frontier for large-scale shell model calculations.

  7. Influence of Neutron Enrichment on Disintegration Modes of Compound Nuclei

    E-Print Network [OSTI]

    E. Bonnet; J. P. Wieleczko; A. Chbihi; J. D. Frankland; J. Moisan; F. Rejmund; J. Gomez del Campo; A. Galindo-Uribarri; D. Shapira; M. La Commara; B. Martin. D. Pierroutsakou; M. Romoli; E. Rosato; G. Spadaccini. M. Vigilante; S. Barlini; R. Bougault; N. Le Neindre; M. Parlog; B. Tamain; C. Beck; B. Borderie; M. F. Rivet; R. Dayras; L. Nalpas; G. De Angelis; T. Glodariou; V. Kravchuk; Ph. Lautesse; A. D. Onofrio; R. Roy

    2008-08-21T23:59:59.000Z

    Cross sections, kinetic energy and angular distributions of fragments with charge 6$\\le$Z$\\le$28 emitted in 78,82Kr+40C at 5.5 MeV/A reactions were measured at the GANIL facility using the INDRA apparatus. This experiment aims to investigate the influence of the neutron enrichment on the decay mechanism of excited nuclei. Data are discussed in comparison with predictions of transition state and Hauser-Feshbach models.

  8. Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

    E-Print Network [OSTI]

    Baryshevsky, V G

    2015-01-01T23:59:59.000Z

    We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magnetic moment of negatively-charged particles (e.g., beauty baryons), for which the channeling effect is hampered due to far more rapid dechanneling as compared to that for positively-charged particles. Channeling of particles in either straight or bent crystals with polarized nuclei could be used for polarization and the analysis thereof of high-energy particles.

  9. A counter-charge layer in generalized solvents framework for electrical double layers in neat and hybrid ionic liquid electrolytes

    SciTech Connect (OSTI)

    Huang, Jingsong [ORNL; Feng, Guang [Clemson University; Sumpter, Bobby G [ORNL; Qiao, Rui [ORNL; Meunier, Vincent [ORNL

    2011-01-01T23:59:59.000Z

    Room-temperature ionic liquids (RTILs) have received significant attention as electrolytes due to a number of attractive properties such as their wide electrochemical windows. Since electrical double layers (EDLs) are the cornerstone for the applications of RTILs in electrochemical systems such as supercapacitors, it is important to develop an understanding of the structure capacitance relationships for these systems. Here we present a theoretical framework termed counter-charge layer in generalized solvents (CGS) for describing the structure and capacitance of the EDLs in neat RTILs and in RTILs mixed with different mass fractions of organic solvents. Within this framework, an EDL is made up of a counter-charge layer exactly balancing the electrode charge, and of polarized generalized solvents (in the form of layers of ion pairs, each of which has a zero net charge but has a dipole moment the ion pairs thus can be considered as a generalized solvent) consisting of all RTILs inside the system except the counter-ions in the counter-charge layer, together with solvent molecules if present. Several key features of the EDLs that originate from the strong ion ion correlation in RTILs, e.g., overscreening of electrode charge and alternating layering of counter-ions and co-ions, are explicitly incorporated into this framework. We show that the dielectric screening in EDLs is governed predominately by the polarization of generalized solvents (or ion pairs) in the EDL, and the capacitance of an EDL can be related to its microstructure with few a priori assumptions or simplifications. We use this framework to understand two interesting phenomena observed in molecular dynamics simulations of EDLs in a neat IL of 1-butyl-3- methylimidazolium tetrafluoroborate ([BMIM][BF4]) and in a mixture of [BMIM][BF4] and acetonitrile (ACN): (1) the capacitance of the EDLs in the [BMIM][BF4]/ACN mixture increases only slightly when the mass fraction of ACN in the mixture increases from zero to 50% although the dielectric constant of bulk ACN is more than two times higher than that of neat [BMIM][BF4]; (2) the capacitance of EDLs near negative electrodes (with BMIM+ ion as the counter-ion) is smaller than that near positive electrodes (with BF4as counter-ion) although the closest approaches of both ions to the electrode surface are nearly identical.

  10. Particle acceleration in three-dimensional tearing configurations

    E-Print Network [OSTI]

    Christoph Nodes; Guido T. Birk; Harald Lesch; R. Schopper

    2003-01-17T23:59:59.000Z

    In three-dimensional electromagnetic configurations that result from unstable resistive tearing modes particles can efficiently be accelerated to relativistic energies. To prove this resistive magnetohydrodynamic simulations are used as input configurations for successive test particle simulations. The simulations show the capability of three-dimensional non-linearly evolved tearing modes to accelerate particles perpendicular to the plane of the reconnecting magnetic field components. The simulations differ considerably from analytical approaches by involving a realistic three-dimensional electric field with a non-homogenous component parallel to the current direction. The resulting particle spectra exhibit strong pitch-angle anisotropies. Typically, about 5-8 % of an initially Maxwellian distribution is accelerated to the maximum energy levels given by the macroscopic generalized electric potential structure. Results are shown for both, non-relativistic particle acceleration that is of interest, e.g., in the context of auroral arcs and solar flares, and relativistic particle energization that is relevant, e.g., in the context of active galactic nuclei.

  11. Coherence effects in deep inelastic scattering from nuclei

    SciTech Connect (OSTI)

    Ver Steeg, G. L. (Greg L.); Raufeisen, J. (Jorg)

    2001-01-01T23:59:59.000Z

    A complete theoretical picture of multiple scattering processes in QCD remains elusive. In deep inelastic scattering experiments (DIS), we hope to find out information about the internal structure of nuclei from inelastically scattering high-energy electrons off them. The electrons interact via virtual photon exchange with the target. In the target rest frame the virtual photon splits into a quark-antiquark pair which is then scattered off the target color field. At high energies, coherent multiple scattering within the nucleus takes place. We develop a model that uses a parameterization of scattering cross section of the quark-antiquark pair off the proton to predict the cross section suppression known as shadowing in larger nuclei. This model takes the possibility of multiple scattering into account using Glauber high-energy collision theory. In large nuclei we must also move beyond the eikonal approximation by correcting for the finite lifetime of the quark-antiquark pair inside the nucleus. Results and implications of this model in relation to available data will be discussed. Finally, application of this type of model to predicting gluon densities will be considered. Understanding this process can give us insights into the more oomplicated scattering taking place in heavy ion colliders such as RHIC and LHC.

  12. The distribution of nuclear quantum states in cold'' rotating nuclei

    SciTech Connect (OSTI)

    Garrett, J.D.; German, J.R. (Oak Ridge National Lab., TN (United States)); Courtney, L. (Tennessee Univ., Knoxville, TN (United States). Dept. of Physics and Astronomy); Espino, J.M. (Seville Univ. (Spain))

    1991-01-01T23:59:59.000Z

    A statistical analysis of the distribution of level spacings for states with the same spin and parity is described in which the average spacing is calculated for the total ensemble. The resulting distribution of level spacings for states of deformed nuclei with A = 155--185 and Z = 62--77 is the closest to that of a Poisson distribution yet obtained for nuclear levels. However, when only the even-spin, positive-parity data for even-even nuclei are considered, the level-spacing distribution becomes double peaked. The anomalously-large separations are shown to be the result of the low energy of the strongly-correlated, completely-paired yrast configuration of even-even nuclei. Average values of the level spacings also are discussed as a function of spin, parity, and nuclear type (even-even, even-Z- odd-N, etc.). Likewise, deviations from a Poisson distribution for several spacings (s) less than about 60 keV are compared with similar values for {sup 116}Sn on an absolute scale. Such discrepancies are attributed to interactions (level repulsions) which become increasingly significant for s {le} 60 keV. 18 refs., 10 figs.

  13. Photoproduction of $?(1520)$ hyperons from nuclei near the threshold

    E-Print Network [OSTI]

    E. Ya. Paryev

    2011-12-01T23:59:59.000Z

    We present a theoretical investigation of $\\Lambda(1520)$ attenuation in ${\\gamma}A$ reactions near the threshold. It is performed in the framework of a collision model based on the nuclear spectral function. The model accounts for both primary photon-nucleon ${\\gamma}N \\to K\\Lambda(1520)$ and secondary pion-nucleon ${\\pi}N \\to K\\Lambda(1520)$ production processes. We calculate the target mass and momentum dependences of the forward $\\Lambda(1520)$ hyperon production from nuclei at photon energy of 2 GeV as well as for two options for its in-medium width. We find that the considered dependences are markedly sensitive to this width. Our studies also demonstrate that the secondary channel ${\\pi}N \\to K\\Lambda(1520)$ plays a substantial role in the intermediate momentum $\\Lambda(1520)$ photoproduction on nuclei in the chosen kinematics and, hence, is to be taken into account in the analysis of $\\Lambda(1520)$ hyperon photoproduction from nuclei with the aim to get information on its width in the matter.

  14. Regularization of zero-range effective interactions in finite nuclei

    E-Print Network [OSTI]

    Marco Brenna; Gianluca Colň; Xavier Roca-Maza

    2014-10-06T23:59:59.000Z

    The problem of the divergences which arise in beyond mean-field calculations, when a zero-range effective interaction is employed, has not been much considered so far. Some of us have proposed, quite recently, a scheme to regularize a zero-range Skyrme-type force when it is employed to calculate the total energy, at second-order perturbation theory level, in uniform matter. Although this scheme looked promising, the extension for finite nuclei is not straightforward. We introduce such procedure in the current paper, by proposing a regularization procedure that is similar, in spirit, to the one employed to extract the so-called V_{\\rm low-k} from the bare force. Although this has been suggested already by B.G. Carlsson and collaborators, the novelty of our work consists in setting on equal footing uniform matter and finite nuclei; in particular, we show how the interactions that have been regularized in uniform matter behave when they are used in a finite nucleus with the corresponding cutoff. We also address the problem of the validity of the perturbative approach in finite nuclei for the total energy.

  15. Incoherent photoproduction of pseudoscalar mesons off nuclei at forward angles

    SciTech Connect (OSTI)

    Gevorgyan, Sergey [JINR; Gasparian, Ashot H. [North Carolina Ag. and Tech. St. U; Gan, Liping [University of North Carolina at Wilmington; Larin, Ilya F. [ITEP, Moscow; Khandaker, Mahbubul A. [Idaho State U

    2012-01-01T23:59:59.000Z

    Recent advances in the photon tagging facilities together with the novel, high-resolution fast calorimetry make it possible to perform photoproduction cross section measurements of pseudoscalar mesons on nuclei with a percent level accuracy. The extraction of the radiative decay widths, needed for testing the symmetry breaking effects in QCD, from these measurements at small angles is done by the Primakoff method. This method requires theoretical treatment of all processes participating in these reactions at the same percent level. The most updated description of general processes, including the nuclear coherent amplitude, is done in our previous paper. In this work, in the framework of the Glauber multiple scattering theory, we obtain analytical expressions for the incoherent cross section of the photoproduction of pseudoscalar mesons off nuclei accounting for the mesons absorption in nuclei and the Pauli suppression at forward production angles. As illustrations of the obtained formulas, we calculate the incoherent cross section for photoproduction from a closed shell nucleus, {sup 16}O, and from an unclosed shell nucleus, {sup 12}C. These calculations allow one to compare different approaches and estimate their impact on the incoherent cross section of the processes under consideration.

  16. Incoherent photoproduction of pseudoscalar mesons off nuclei at forward angles

    E-Print Network [OSTI]

    S. Gevorkyan; A. Gasparian; L. Gan; I. Larin; M. Khandaker

    2009-08-10T23:59:59.000Z

    Recent advances in the photon tagging facilities together with the novel, high resolution fast calorimetry made possible to perform photoproduction cross section measurements of pseudoscalar mesons on nuclei with a percent level accuracy. The extraction of the radiative decay widths, needed for testing the symmetry breaking effects in QCD, from these measurements at small angles is done by the Primakoff method. This method requires theoretical treatment of all processes participating in these reactions at the same percent level. The most updated description of general processes, including the nuclear coherent amplitude, is done in our previous paper. In this work, based on the framework of Glauber multiple scattering theory, we obtain analytical expressions for the incoherent cross section of the photoproduction of pseudoscalar mesons off nuclei accounting for the mesons absorption in nuclei and Pauli suppression at forward production angles. As illustrations of the obtained formulas, we calculate the incoherent cross section for photoproduction from a closed shell nucleus, 16^O, and from an unclosed shell nucleus, 12^C. These calculations allow one to compare different approaches and estimate their impact on the incoherent cross section of the processes under consideration.

  17. Adhesive particle shielding

    DOE Patents [OSTI]

    Klebanoff, Leonard Elliott (Dublin, CA); Rader, Daniel John (Albuquerque, NM); Walton, Christopher (Berkeley, CA); Folta, James (Livermore, CA)

    2009-01-06T23:59:59.000Z

    An efficient device for capturing fast moving particles has an adhesive particle shield that includes (i) a mounting panel and (ii) a film that is attached to the mounting panel wherein the outer surface of the film has an adhesive coating disposed thereon to capture particles contacting the outer surface. The shield can be employed to maintain a substantially particle free environment such as in photolithographic systems having critical surfaces, such as wafers, masks, and optics and in the tools used to make these components, that are sensitive to particle contamination. The shield can be portable to be positioned in hard-to-reach areas of a photolithography machine. The adhesive particle shield can incorporate cooling means to attract particles via the thermophoresis effect.

  18. Simulation of particle agglomeration using dissipative particle dynamics

    E-Print Network [OSTI]

    Mokkapati, Srinivas Praveen

    2009-05-15T23:59:59.000Z

    Attachment of particles to one another due to action of certain inter-particle forces is called as particle agglomeration. It has applications ranging from efficient capture of ultra-fine particles generated in coal-burning boilers to effective...

  19. P-odd and P-even correlations for third particles in ternary fission

    SciTech Connect (OSTI)

    Bunakov, V. E., E-mail: bunakov@vb13190.spbu.edu; Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V. [Russian Academy of Sciences, Petersburg Nuclear Physics Institute (Russian Federation)

    2008-12-15T23:59:59.000Z

    Within quantum-mechanical fission theory, P-odd and P-even correlations in angular distributions of products of the ternary fission of nuclei that is induced by polarized cold and thermal neutrons are investigated on the basis of a nonevaporative mechanism of third-particle emission and under the assumption that a two-humped fission barrier exists. It is shown that these correlations for third particles are induced by the analogous correlations for ternary-fission fragments, the latter being transferred to the third particle because of the kinematical conditions of third-particle emission that are associated with the charge and mass asymmetry of fragments. Optimum methods for observing the above correlations for third particles are discussed. The possibility of discovering the emission of prescission neutrons in the fission process against the background of evaporated neutrons by means of studying P-odd and P-even correlations is explored.

  20. Degeneracies of particle and nuclear physics uncertainties in neutrinoless double beta decay

    E-Print Network [OSTI]

    Lisi, E; Simkovic, F

    2015-01-01T23:59:59.000Z

    Theoretical estimates for the half life of neutrinoless double beta decay in candidate nuclei are affected by both particle and nuclear physics uncertainties, which may complicate the interpretation of decay signals or limits. We study such uncertainties and their degeneracies in the following context: three nuclei of great interest for large-scale experiments (76-Ge, 130-Te, 136-Xe), two representative particle physics mechanisms (light and heavy Majorana neutrino exchange), and a large set of nuclear matrix elements (NME), computed within the quasiparticle random phase approximation (QRPA). It turns out that the main theoretical uncertainties, associated with the effective axial coupling g_A and with the nucleon-nucleon potential, can be parametrized in terms of NME rescaling factors, up to small residuals. From this parametrization, the following QRPA features emerge: (1) the NME dependence on g_A is milder than quadratic; (2) in each of the two mechanisms, the relevant lepton flavor violating parameter is...

  1. Nuclear & Particle Physics, Astrophysics, Cosmology

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nuclear & Particle Physics science-innovationassetsimagesicon-science.jpg Nuclear & Particle Physics, Astrophysics, Cosmology National security depends on science and...

  2. Complementary optical-potential analysis of alpha-particle elastic scattering and induced reactions at low energies

    E-Print Network [OSTI]

    M. Avrigeanu; A. C. Obreja; F. L. Roman; V. Avrigeanu; W. von Oertzen

    2008-08-05T23:59:59.000Z

    A previously derived semi-microscopic analysis based on the Double Folding Model, for alpha-particle elastic scattering on A~100 nuclei at energies below 32 MeV, is extended to medium mass A ~ 50-120 nuclei and energies from ~13 to 50 MeV. The energy-dependent phenomenological imaginary part for this semi-microscopic optical model potential was obtained including the dispersive correction to the microscopic real potential, and used within a concurrent phenomenological analysis of the same data basis. A regional parameter set for low-energy alpha-particles entirely based on elastic-scattering data analysis was also obtained for nuclei within the above-mentioned mass and energy ranges. Then, an ultimate assessment of (alpha,gamma), (alpha,n) and (alpha,p) reaction cross sections concerned target nuclei from 45Sc to 118Sn and incident energies below ~12 MeV. The former diffuseness of the real part of optical potential as well as the surface imaginary-potential depth have been found responsible for the actual difficulties in the description of these data, and modified in order to obtain an optical potential which describe equally well both the low energy elastic-scattering and induced-reaction data of alpha-particles.

  3. Review of Particle Physics

    E-Print Network [OSTI]

    Nakamura, Kenzo

    2010-01-01T23:59:59.000Z

    for non-accelerator physics . . . . . . . . . 328 ParticleColliders, accelerator physics of Coupling between matterdetectors for non-accelerator physics (Figure 29.5) . . .

  4. Deformation of the very neutron-deficient rare-earth nuclei produced with the SPIRAL 76Kr radioactive beam and studied with EXOGAM + DIAMANT

    SciTech Connect (OSTI)

    Redon, N.; Guinet, D.; Lautesse, Ph.; Meyer, M.; Rosse, B.; Stezowski, O. [IPN Lyon, IN2P3/CNRS, Universite Claude Bernard Lyon-1, F-69622 Villeurbanne Cedex (France); Prevost, A. [IPN Lyon, IN2P3/CNRS, Universite Claude Bernard Lyon-1, F-69622 Villeurbanne Cedex (France); CSNSM Orsay, IN2P3/CNRS, Bat 104, F-91405 Orsay Campus (France); Nolan, P.J.; Andreoiu, C.; Boston, A.J.; Descovich, M.; Evans, A.O.; Gros, S.; Norman, J.; Page, R.D.; Paul, E.S.; Rainovski, G.; Sampson, J. [Oliver Lodge Laboratory, University of Liverpool, P.O. Box 147, Liverpool L69 7ZE (United Kingdom); France, G. de; Casandjian, J. M. [GANIL, B.P. 55027, F-14076 Caen Cedex (France)] [and others

    2004-02-27T23:59:59.000Z

    The structure of the very neutron-deficient rare-earth nuclei has been investigated in the first experiment with the EXOGAM gamma array coupled to the DIAMANT light charged particle detector using radioactive beam of 76Kr delivered by the SPIRAL facility. Very neutron-deficient Pr, Nd and Pm isotopes have been populated at rather high spin by the reaction 76Kr + 58Ni at a beam energy of 328 MeV. We report here the first results of this experiment.

  5. New measurements of high-momentum nucleons and short-range structures in nuclei

    E-Print Network [OSTI]

    Fomin, N; Asaturyan, R; Benmokhtar, F; Boeglin, W; Bosted, P; Bruell, A; Bukhari, M H S; Chudakov, E; Clasie, B; Connell, S H; Dalton, M M; Daniel, A; Day, D B; Dutta, D; Ent, R; Fassi, L El; Fenker, H; Filippone, B W; Garrow, K; Gaskell, D; Hill, C; Holt, R J; Horn, T; Jones, M K; Jourdan, J; Kalantarians, N; Keppel, C E; Kiselev, D; Kotulla, M; Lindgren, R; Lung, A F; Malace, S; Markowitz, P; McKee, P; Meekins, D G; Mkrtchyan, H; Navasardyan, T; Niculescu, G; Opper, A K; Perdrisat, C; Potterveld, D H; Punjabi, V; Qian, X; Reimer, P E; Roche, J; Rodriguez, V M; Rondon, O; Schulte, E; Seely, J; Segbefia, E; Slifer, K; Smith, G R; Solvignon, P; Tadevosyan, V; Tajima, S; Tang, L; Testa, G; Trojer, R; Tvaskis, V; Vulcan, W F; Wasko, C; Wesselmann, F R; Wood, S A; Wright, J; Zheng, X

    2011-01-01T23:59:59.000Z

    We present new, high-Q^2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

  6. New measurements of high-momentum nucleons and short-range structures in nuclei

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fomin, N; Arrington, J; Benmokhtar, F; Boeglin, W; Bosted, P; Bruell, A; Bukhari, M.H. S; Chudakov, E; Clasie, B; Connell, S H; Dalton, M M; Daniel, A; Day, D B; Dutta, D; Ent, R; El Fassi, L; Fenker, H; Filippone, B W; Garrow, K; Gaskell, D; Hill, C; Holt, R J; Horn, T; Jones, M K; Jourdan, J; Kalantarians, N; Keppel, C E; Kiselev, D; Kotulla, M; Lindgren, R; Lung, A F; Malace, S; Markowitz, P; McKee, P; Meekins, D G; Mkrtchyan, H; Navasardyan, T; Niculescu, G; Opper, A K; Perdrisat, C; Potterveld, D H; Punjabi, V; Qian, X; Reimer, P E; Roche, J; Rodriguez, V M; Rondon, O; Schulte, E; Seely, J; Segbefia, E; Slifer, K; Smith, G R; Solvignon, P; Tadevosyan, V; Tajima, S; Tang, L; Testa, G; Trojer, R; Tvaskis, V; Vulcan, W F; Wasko, C; Wesselmann, F R; Wood, S A

    2012-02-29T23:59:59.000Z

    We present new, high-Q2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

  7. Thermal properties of light nuclei from $^{12}$C+$^{12}$C fusion-evaporation reactions

    E-Print Network [OSTI]

    L Morelli; G Baiocco; M D'Agostino; F Gulminelli; M Bruno; U Abbondanno; S Appannababu; S Barlini; M Bini; G Casini; M Cinausero; M Degerlier; D Fabris; N Gelli; F Gramegna; V L Kravchuk; T Marchi; G Pasquali; S Piantelli; S Valdré; Ad R Raduta

    2014-04-14T23:59:59.000Z

    The $^{12}$C+$^{12}$C reaction at 95 MeV has been studied through the complete charge identification of its products by means of the GARFIELD+RCo experimental set-up at INFN Laboratori Nazionali di Legnaro (LNL). In this paper, the first of a series of two, a comparison to a dedicated Hauser-Feshbach calculation allows to select a set of dissipative events which corresponds, to a large extent, to the statistical evaporation of highly excited $^{24}$Mg. Information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain is also extracted. The set of data puts strong constraints on the behaviour of the level density of light nuclei above the threshold for particle emission. In particular, a fast increase of the level density parameter with excitation energy is supported by the data. Residual deviations from a statistical behaviour are seen in two specific channels, and tentatively associated with a contamination from direct reactions and/or $\\alpha$-clustering effects. These channels are studied in further details in the second paper of the series.

  8. Fermion space charge in narrow-band gap semiconductors, Weyl semimetals and around highly charged nuclei

    E-Print Network [OSTI]

    Eugene B. Kolomeisky; Joseph P. Straley; Hussain Zaidi

    2013-10-15T23:59:59.000Z

    The field of charged impurities in narrow-band gap semiconductors and Weyl semimetals can create electron-hole pairs when the total charge $Ze$ of the impurity exceeds a value $Z_{c}e$. The particles of one charge escape to infinity, leaving a screening space charge. The result is that the observable dimensionless impurity charge $Q_{\\infty}$ is less than $Z$ but greater than $Z_{c}$. There is a corresponding effect for nuclei with $Z >Z_{c} \\approx 170$, however in the condensed matter setting we find $Z_{c} \\simeq 10$. Thomas-Fermi theory indicates that $Q_{\\infty} = 0$ for the Weyl semimetal, but we argue that this is a defect of the theory. For the case of a highly-charged recombination center in a narrow band-gap semiconductor (or of a supercharged nucleus), the observable charge takes on a nearly universal value. In Weyl semimetals the observable charge takes on the universal value $Q_{\\infty} = Z_{c}$ set by the reciprocal of material's fine structure constant.

  9. Degeneracies of particle and nuclear physics uncertainties in neutrinoless double beta decay

    E-Print Network [OSTI]

    E. Lisi; A. Rotunno; F. Simkovic

    2015-06-12T23:59:59.000Z

    Theoretical estimates for the half life of neutrinoless double beta decay in candidate nuclei are affected by both particle and nuclear physics uncertainties, which may complicate the interpretation of decay signals or limits. We study such uncertainties and their degeneracies in the following context: three nuclei of great interest for large-scale experiments (76-Ge, 130-Te, 136-Xe), two representative particle physics mechanisms (light and heavy Majorana neutrino exchange), and a large set of nuclear matrix elements (NME), computed within the quasiparticle random phase approximation (QRPA). It turns out that the main theoretical uncertainties, associated with the effective axial coupling g_A and with the nucleon-nucleon potential, can be parametrized in terms of NME rescaling factors, up to small residuals. From this parametrization, the following QRPA features emerge: (1) the NME dependence on g_A is milder than quadratic; (2) in each of the two mechanisms, the relevant lepton flavor violating parameter is largely degenerate with the NME rescaling factors; and (3) the light and heavy neutrino exchange mechanisms are basically degenerate in the above three nuclei. We comment on the challenging theoretical and experimental improvements required to reduce such particle and nuclear physics uncertainties and their degeneracies.

  10. Low-temperature Bessel beam trap for single submicrometer aerosol particle studies

    SciTech Connect (OSTI)

    Lu, Jessica W.; Chasovskikh, Egor; Stapfer, David [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Isenor, Merrill; Signorell, Ruth [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada)

    2014-09-01T23:59:59.000Z

    We report on a new instrument for single aerosol particle studies at low temperatures that combines an optical trap consisting of two counter-propagating Bessel beams (CPBBs) and temperature control down to 223 K (?50?°C). The apparatus is capable of capturing and stably trapping individual submicrometer- to micrometer-sized aerosol particles for up to several hours. First results from studies of hexadecane, dodecane, and water aerosols reveal that we can trap and freeze supercooled droplets ranging in size from ?450 nm to 5500 nm (radius). We have conducted homogeneous and heterogeneous freezing experiments, freezing-melting cycles, and evaporation studies. To our knowledge, this is the first reported observation of the freezing process for levitated single submicrometer-sized droplets in air using optical trapping techniques. These results show that a temperature-controlled CPBB trap is an attractive new method for studying phase transitions of individual submicrometer aerosol particles.

  11. An array of low-background 3He proportional counters for theSudbury Neutrino Observatory

    SciTech Connect (OSTI)

    Amsbaugh, J.F.; Anaya, J.M.; Banar, J.; Bowles, T.J.; Browne,M.C.; Bullard, T.V.; Burritt, T.H.; Cox-Mobrand, G.A.; Dai, X.; H.Deng,X.; Di Marco, M.; Doe, P.J.; Dragowsky, M.R.; Duba, C.A.; Duncan, F.A.; Earle, E.D.; Elliott, S.R.; Esch, E.-I.; Fergani, H.; Formaggio, J.A.; Fowler, M.M.; Franklin, J.E.; Geissbuehler, P.; Germani, J.V.; Goldschmidt, A.; Guillian, E.; Hallin, A.L.; Harper, G.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heise, J.; Hime, A.; Howe, M.A.; Huang, M.; Kormos, L.L.; Kraus, C.; Krauss, C.B.; Law, J.; Lawson, I.T.; Lesko,K.T.; Loach, J.C.; Majerus, S.; Manor, J.; McGee, S.; Miknaitis, K.K.S.; Miller, G.G.; Morissette, B.; Myers, A.; Oblath, N.S.; O'Kee, H.M.; Ollerhead, R.W.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Reitzner,S.D.; Rielage, K.; Robertson, R.G.H.; Skensved, P.; Smith, A.R.; Smith,M.W.E.; Steiger, T.D.; Stonehill,L.C.; Thornewell, P.M.; Tolich, N.; VanDevender, B.A.; VanWechel, T.D.; Wall, B.L.; Tseung, H.W.C.; Wendland,J.; West, N.; Wilhelmy, J.B.; Wilkerson, J.F.; Wouters, J.M.

    2007-02-01T23:59:59.000Z

    An array of Neutral-Current Detectors (NCDs) has been builtin order to make a unique measurement of the total active ux of solarneutrinos in the Sudbury Neutrino Observatory (SNO). Data in the thirdphase of the SNO experiment were collected between November 2004 andNovember 2006, after the NCD array was added to improve theneutral-current sensitivity of the SNO detector. This array consisted of36 strings of proportional counters lled with a mixture of 3He and CF4gas capable of detecting the neutrons liberated by the neutrino-deuteronneutral current reaction in the D2O, and four strings lled with a mixtureof 4He and CF4 gas for background measurements. The proportional counterdiameter is 5 cm. The total deployed array length was 398 m. The SNO NCDarray is the lowest-radioactivity large array of proportional countersever produced. This article describes the design, construction,deployment, and characterization of the NCD array, discusses theelectronics and data acquisition system, and considers event signaturesand backgrounds.

  12. High and low frequency instabilities driven by counter-streaming electron beams in space plasmas

    SciTech Connect (OSTI)

    Mbuli, L. N. [South African National Space Agency (SANSA) Space Science, P.O. Box 32, Hermanus 7200, Republic of South Africa (South Africa); University of the Western Cape, Robert Sobukwe Road, Bellville 7535, Republic of South Africa (South Africa); Maharaj, S. K. [South African National Space Agency (SANSA) Space Science, P.O. Box 32, Hermanus 7200, Republic of South Africa (South Africa); Bharuthram, R. [University of the Western Cape, Robert Sobukwe Road, Bellville 7535, Republic of South Africa (South Africa)

    2014-05-15T23:59:59.000Z

    A four-component plasma composed of a drifting (parallel to ambient magnetic field) population of warm electrons, drifting (anti-parallel to ambient magnetic field) cool electrons, stationary hot electrons, and thermal ions is studied in an attempt to further our understanding of the excitation mechanisms of broadband electrostatic noise (BEN) in the Earth's magnetospheric regions such as the magnetosheath, plasmasphere, and plasma sheet boundary layer (PSBL). Using kinetic theory, beam-driven electrostatic instabilities such as the ion-acoustic, electron-acoustic instabilities are found to be supported in our multi-component model. The dependence of the instability growth rates and real frequencies on various plasma parameters such as beam speed, number density, temperature, and temperature anisotropy of the counter-streaming (relative to ambient magnetic field) cool electron beam are investigated. It is found that the number density of the anti-field aligned cool electron beam and drift speed play a central role in determining which instability is excited. Using plasma parameters which are closely correlated with the measurements made by the Cluster satellites in the PSBL region, we find that the electron-acoustic and ion-acoustic instabilities could account for the generation of BEN in this region.

  13. Controlling Low-Rate Signal Path Microdischarge for an Ultra-Low-Background Proportional Counter

    SciTech Connect (OSTI)

    Mace, Emily K.; Aalseth, Craig E.; Bonicalzi, Ricco; Day, Anthony R.; Hoppe, Eric W.; Keillor, Martin E.; Myers, Allan W.; Overman, Cory T.; Seifert, Allen

    2013-05-01T23:59:59.000Z

    ABSTRACT Pacific Northwest National Laboratory (PNNL) has developed an ultra-low-background proportional counter (ULBPC) made of high purity copper. These detectors are part of an ultra-low-background counting system (ULBCS) in the newly constructed shallow underground laboratory at PNNL (at a depth of ~30 meters water-equivalent). To control backgrounds, the current preamplifier electronics are located outside the ULBCS shielding. Thus the signal from the detector travels through ~1 meter of cable and is potentially susceptible to high voltage microdischarge and other sources of electronic noise. Based on initial successful tests, commercial cables and connectors were used for this critical signal path. Subsequent testing across different batches of commercial cables and connectors, however, showed unwanted (but still low) rates of microdischarge noise. To control this noise source, two approaches were pursued: first, to carefully validate cables, connectors, and other commercial components in this critical signal path, making modifications where necessary; second, to develop a custom low-noise, low-background preamplifier that can be integrated with the ULBPC and thus remove most commercial components from the critical signal path. This integrated preamplifier approach is based on the Amptek A250 low-noise charge-integrating preamplifier module. The initial microdischarge signals observed are presented and characterized according to the suspected source. Each of the approaches for mitigation is described, and the results from both are compared with each other and with the original performance seen with commercial cables and connectors.

  14. Characterization of a Spherical Proportional Counter in argon-based mixtures

    E-Print Network [OSTI]

    F. J. Iguaz; A. Rodriguez; J. F. Castel; I. G. Irastorza

    2015-01-07T23:59:59.000Z

    The Spherical Proportional Counter is a novel type of radiation detector, with a low energy threshold (typically below 100 eV) and good energy resolution. This detector is being developed by the network NEWS, which includes several applications. We can name between many others Dark Matter searches, low level radon and neutron counting or low energy neutrino detection from supernovas or nuclear reactors via neutrino-nucleus elastic scattering. In this context, this works will present the characterization of a spherical detector of 1 meter diameter using two argon-based mixtures (with methane and isobutane) and for gas pressures between 50 and 1250 mbar. In each case, the energy resolution shows its best value in a wide range of gains, limited by the ballistic effect at low gains and by ion-backflow at high gains. Moreover, the best energy resolution shows a degradation with pressure. These effects will be discussed in terms of gas avalanche properties. Finally, the effect of an electrical field corrector in the homogenity of the gain and the energy threshold measured in our setup will be also discussed.

  15. Shape phase transition in the odd Sm nuclei: effective order parameter and odd-even effect

    E-Print Network [OSTI]

    Yu Zhang; Xin Guan; Yin Wang; Yan Zuo; Li-na Bao; Feng Pan

    2015-04-20T23:59:59.000Z

    Some binding-energy-related quantities serving as effective order parameters have been used to analyze the shape phase transition in the odd Sm nuclei. It is found that the signals of phase transition in the odd Sm nuclei are greatly enhanced in contrast to the even Sm nuclei. A further analysis shows that the transitional behaviors related to pairing in the Sm nuclei can be well described by the mean field plus pairing interaction model, with a monotonic decrease in the pairing strength $G$.

  16. Shape phase transition in the odd Sm nuclei: effective order parameter and odd-even effect

    E-Print Network [OSTI]

    Zhang, Yu; Wang, Yin; Zuo, Yan; Bao, Li-na; Pan, Feng

    2015-01-01T23:59:59.000Z

    Some binding-energy-related quantities serving as effective order parameters have been used to analyze the shape phase transition in the odd Sm nuclei. It is found that the signals of phase transition in the odd Sm nuclei are greatly enhanced in contrast to the even Sm nuclei. A further analysis shows that the transitional behaviors related to pairing in the Sm nuclei can be well described by the mean field plus pairing interaction model, with a monotonic decrease in the pairing strength $G$.

  17. Comment on "Measurement of 2- and 3-Nucleon Short-Range Correlation Probabilities in Nuclei"

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Higinbotham, Douglas W. [Jefferson Lab, Newport News; Hen, Or [Tel Aviv University

    2015-04-01T23:59:59.000Z

    Comment on 'Measurement of 2- and 3-nucleon short range correlation probabilities in nuclei' shows how the reported three-nucleon plateau was likely due to resolution effects.

  18. Transverse momentum broadening of hadrons produced in semi-inclusive deep-inelastic scattering on nuclei.

    E-Print Network [OSTI]

    on nuclei. A. Airapetian,12, 15 N. Akopov,26 Z. Akopov,5 E.C. Aschenauer,6 W. Augustyniak,25 A. Avetissian

  19. Hadron-hadron and hadron-nuclei collisions at high energies

    E-Print Network [OSTI]

    G. Giacomelli; R. Giacomelli

    2000-11-15T23:59:59.000Z

    A brief review is made of the present situation of hadron-hadron and hadron-nuclei total elastic and inelastic cross sections at high energies

  20. active galactic nuclei-blown: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for studying a large variety of astrophysical phenomena, ranging from stars and their environment to interstellar and intergalactic medium, active galactic nuclei (AGN) and...

  1. Discovery of Active Galactic Nuclei in Mid- and Far-Infrared Deep Surveys with ISO

    E-Print Network [OSTI]

    Yoshiaki Taniguchi

    2001-11-01T23:59:59.000Z

    We present a summary on the discovery of active galactic nuclei in mid- and far-infrared deep surveys with use of the Infrared Space Observatory.

  2. Determining size-specific emission factors for environmental tobacco smoke particles

    SciTech Connect (OSTI)

    Klepeis, Neil E.; Apte, Michael G.; Gundel, Lara A.; Sextro, Richard G.; Nazaroff, William W.

    2002-07-07T23:59:59.000Z

    Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides--in addition to estimates of the emissions size distribution and integrated emission factors--estimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1-2+ micrometer diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01-1+ micrometer diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange-rate 20 m{sup 3} chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1-2 hours after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle emission factors were fit with log-normal distributions, yielding an average mass median diameter of 0.2 micrometers and an average geometric standard deviation of 2.3 with no systematic differences between cigars and cigarettes. The equivalent total particle emission rate, obtained integrating each size distribution, was 0.2-0.7 mg/min for cigars and 0.7-0.9 mg/min for cigarettes.

  3. Effects of Distortion on the Intercluster Motion in Light Nuclei

    SciTech Connect (OSTI)

    Pizzone, R. G.; Spitaleri, C.; Cherubini, S.; La Cognata, M.; Lamia, L.; Romano, S. [INFN Laboratori Nazionali del Sud, Catania (Italy); DMFCI-Universita di Catania, Catania (Italy); Bertulani, C. [Texas A and M University, Commerce (United States); Mukhamedzhanov, A. [Cyclotron Institute, Texas A and M University, College Station (United States); Blokhintsev, L. [University of Moscow, Moscow (Russian Federation); Irgaziev, B. [University of Tashkent, Tashkent (Uzbekistan); Miljanic, D. [Ruder Boskovic Institute, Zagreb (Croatia); Tumino, A. [Universita Kore, Enna (Italy)

    2009-08-26T23:59:59.000Z

    Deuteron induced quasi-free scattering and reactions have been extensively investigated in the past few decades as well as {sup 6}Li, {sup 3}He and {sup 9}Be induced ones. This was done not only for nuclear structure and processes study but also for the important astrophysical implication (Trojan Horse Method, THM). In particular the width of the spectator momentum distribution in {sup 6}Li and deuterium, which have widely been used as a Trojan Horse nuclei, will be studied as a function of the transferred momentum. Trojan horse method applications will also be discussed in these cases.

  4. Core excitation effects in the breakup of halo nuclei

    SciTech Connect (OSTI)

    Moro, A. M.; Diego, R. de; Lay, J. A.; Crespo, R.; Johnson, R. C.; Arias, J. M.; Gomez-Camacho, J. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal) and Departamento de Fisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Prof. Cavaco Silva, Taguspark (Portugal); Physics Department, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain) and Centro Nacional de Aceleradores, Universidad de Sevilla/Junta de Andalucia, E-41092 Sevilla (Spain)

    2012-10-20T23:59:59.000Z

    The role of core excitation in the structure and dynamics of two-body halo nuclei is investigated. We present calculations for the resonant breakup of {sup 11}Be on protons at an incident energy of 63.7 MeV/nucleon, where core excitation effects were shown to be important. To describe the reaction, we use a recently developed extension of the DWBA formalism which incorporates these core excitation effects within the no-recoil approximation. The validity of the no-recoil approximation is also examined by comparing with DWBA calculations which take into account core recoil. In addition, calculations with two different continuum representations are presented and compared.

  5. Excitation energy dependence of symmetry energy of finite nuclei

    E-Print Network [OSTI]

    S. K. Samaddar; J. N. De; X. Vinas; M. Centelles

    2007-10-11T23:59:59.000Z

    A finite range density and momentum dependent effective interaction is used to calculate the density and temperature dependence of the symmetry energy coefficient Csym(rho,T) of infinite nuclear matter. This symmetry energy is then used in the local density approximation to evaluate the excitation energy dependence of the symmetry energy coefficient of finite nuclei in a microcanonical formulation that accounts for thermal and expansion effects. The results are in good harmony with the recently reported experimental data from energetic nucleus-nucleus collisions.

  6. Giant Monopole Resonance in Transitional and Deformed-Nuclei

    E-Print Network [OSTI]

    Garg, U.; Bogucki, P.; Bronson, J. D.; Lui, YW; Youngblood, David H.

    1984-01-01T23:59:59.000Z

    =129 MeV on ' ' Sm and ' ' ' Nd to investigate the giant monopole resonance in transitional and deformed nuclei. The experimental data reveal a mixing of I.=0 and I.=2 modes in '" Sm resulting in almost identi- cal angular distributions for the two... components of the giant resonance peaks in the angular range 2'?6. A "splitting" of the giant monopole resonance is observed in ' Nd; the extent of this split- ting is sma11er than that reported for ' "Sm. Comparison is made with the predictions of various...

  7. Lifetimes of N = Z Nuclei As-66 and Br-70

    E-Print Network [OSTI]

    Burch, R. H.; Gagliardi, Carl A.; Tribble, Robert E.

    1988-01-01T23:59:59.000Z

    PHYSICAL REVIEW C VOLUME 38, NUMBER 3 Lifetimes of N =Z nuclei As and Br SEPTEMBER 1988 R. H. Burch Jr., C. A. Gagliardi, and R. E. Tribble Cyclotron Institute, Texas A&M University, College Station, Texas 77843 (Received 5 May 1988) We have... of the target wheel, the detector telescope, and the detector shielding. 1988 The American Physical Society 1366 R. H. BURCH, JR., C. A. GAGLIARDI, AND R. E. TRIBBLE 38 indexer with an antibacklash circuit drove the stepping motor. After each irradiation...

  8. Pulsars: Macro-nuclei with 3-flavour symmetry

    E-Print Network [OSTI]

    Xu, Renxin

    2015-01-01T23:59:59.000Z

    A pulsar-like compact star is the rump left behind after a supernova where normal baryonic matter is intensely compressed by gravity, but the real state of such compressed baryonic matter is still not well understood because of the non-perturbative nature of the fundamental color interaction. We argue that pulsars could be of condensed matter of quark clusters, i.e., "quark-cluster stars" which distinguish from conventional neutron and quark stars. In comparison with 2-flavour symmetric micro-nuclei, a quark-cluster star could simply be considered as a macro-nucleus with 3-flavour symmetry. New research achievements both theoretical and observational are briefly presented.

  9. Photoproduction of eta-mesons from light nuclei

    E-Print Network [OSTI]

    B. Krusche

    2003-04-02T23:59:59.000Z

    In a series of experiments coherent and quasifree eta-photoproduction from light nuclei (4He, 3He, 2H) was investigated with the TAPS-detector at the Mainz MAMI-accelerator. The experiments were motivated by two different subjects: the determination of the isospin structure of the electromagnetic excitation of the S11(1535) resonance and the study of the eta-nucleon and eta-nucleus interaction at small momenta. The results for the deuteron and 4He are summarized and first preliminary results for 3He are presented.

  10. Suppressed fusion cross section for neutron halo nuclei

    E-Print Network [OSTI]

    Makoto Ito; Kazuhiro Yabana; Takashi Nakatsukasa; Manabu Ueda

    2006-01-20T23:59:59.000Z

    Fusion reactions of neutron-halo nuclei are investigated theoretically with a three-body model. The time-dependent wave-packet method is used to solve the three-body Schrodinger equation. The halo neutron behaves as a spectator during the Coulomb dissociation process of the projectile. The fusion cross sections of 11Be-209Bi and 6He-238U are calculated and are compared with measurements. Our calculation indicates that the fusion cross section is slightly hindered by the presence of weakly bound neutrons.

  11. Spectropolarimetry and the Geometry of Type 1 Seyfert Nuclei

    E-Print Network [OSTI]

    Andy Robinson; David J. Axon; James E. Smith

    2002-11-11T23:59:59.000Z

    We describe the results of a detailed study of the polarization properties of the broad H-alpha emission line in Type 1 Seyfert nuclei. Our analysis of these data points to a model in which the broad Balmer lines are emitted by a rotating disk, and are scattered in two main regions - one co-planar with the disk and within the circum-nuclear torus, the other, the polar scattering region, outside the torus but aligned with its axis. The relative importance of the two sources of polarized light is largely determined by the inclination of the system axis to the line-of-sight.

  12. Dynamical Processes in the Central Kpc and Active Galactic Nuclei

    E-Print Network [OSTI]

    Isaac Shlosman

    2003-06-18T23:59:59.000Z

    We discuss different aspects of nested bar dynamics and its effect on the gas flow and fueling of Active Galactic Nuclei. Specifically we focus on the dynamical decoupling between the primary and secondary bars and the gas flow across the bar-bar interface. We analyze the nuclear gaseous bar formation when gas gravity can be neglected or when it dominates. Finally, we discuss the possible effect of flat core, triaxial, dark halos on the formation of galactic bulges and supermassive black holes (SBHs) and argue in favor of SBH-bulge-halo correlation.

  13. Temperature dependence of symmetry energy of finite nuclei

    E-Print Network [OSTI]

    J. N. De; S. K. Samaddar

    2012-02-06T23:59:59.000Z

    The temperature dependence of the symmetry energy and the symmetry free energy coefficients of atomic nuclei is investigated in a finite temperature Thomas-Fermi framework employing the subtraction procedure. A substantial decrement in the symmetry energy coefficient is obtained for finite systems,contrary to those seen for infinite nuclear matter at normal and somewhat subnormal densities. The effect of the coupling of the surface phonons to the nucleonic motion is also considered; this is found to decrease the symmetry energies somewhat at low temperatures.

  14. Thermalization in collisions of large nuclei at high energies

    E-Print Network [OSTI]

    Aleksi Kurkela

    2013-03-19T23:59:59.000Z

    Hydrodynamical analysis of experimental data of ultrarelativistic heavy ion collisions seems to indicate that the hot QCD matter created in the collisions thermalizes very quickly. Theoretically, we have no idea why this should be true. In this proceeding, I will describe how the thermalization takes place in the most theoretically clean limit -- that of large nuclei at asymptotically high energy per nucleon, where the system is described by weak-coupling QCD. In this limit, plasma instabilities dominate the dynamics from immediately after the collision until well after the plasma becomes nearly in equilibrium at time t \\alpha^(-5/2)Q^(-1).

  15. ARM - Field Campaign - SGP Ice Nuclei Characterization Experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa- Polarization DiversityPolarization RadargovCampaignsSGP Ice Nuclei

  16. RESEARCH IN PARTICLE PHYSICS

    SciTech Connect (OSTI)

    Kearns, Edward [Boston Universiy] [Boston Universiy

    2013-07-12T23:59:59.000Z

    This is the final report for the Department of Energy Grant to Principal Investigators in Experimental and Theoretical Particle Physics at Boston University. The research performed was in the Energy Frontier at the LHC, the Intensity Frontier at Super-Kamiokande and T2K, the Cosmic Frontier and detector R&D in dark matter detector development, and in particle theory.

  17. Pileup Per Particle Identification

    E-Print Network [OSTI]

    Daniele Bertolini; Philip Harris; Matthew Low; Nhan Tran

    2014-09-30T23:59:59.000Z

    We propose a new method for pileup mitigation by implementing "pileup per particle identification" (PUPPI). For each particle we first define a local shape $\\alpha$ which probes the collinear versus soft diffuse structure in the neighborhood of the particle. The former is indicative of particles originating from the hard scatter and the latter of particles originating from pileup interactions. The distribution of $\\alpha$ for charged pileup, assumed as a proxy for all pileup, is used on an event-by-event basis to calculate a weight for each particle. The weights describe the degree to which particles are pileup-like and are used to rescale their four-momenta, superseding the need for jet-based corrections. Furthermore, the algorithm flexibly allows combination with other, possibly experimental, probabilistic information associated with particles such as vertexing and timing performance. We demonstrate the algorithm improves over existing methods by looking at jet $p_T$ and jet mass. We also find an improvement on non-jet quantities like missing transverse energy.

  18. alpha-particle-emitting radioimmunoconjugate 227th-rituximab...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Selahattin 5 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

  19. Stimulated Raman scattering of beat wave of two counter-propagating X-mode lasers in a magnetized plasma

    SciTech Connect (OSTI)

    Verma, Kanika; Sajal, Vivek, E-mail: vsajal@rediffmail.com; Varshney, Prateek; Kumar, Ravindra; Sharma, Navneet K. [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307, UP (India)] [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307, UP (India)

    2014-02-15T23:59:59.000Z

    Effects of transverse static magnetic field on stimulated Raman scattering (SRS) of the beat wave excited by two counter-propagating lasers are studied. Two counter-propagating lasers with frequency difference, ?{sub 1}??{sub 2}?2?{sub p}, drive a non resonant space charge beat mode at wave number k{sup ?}{sub 0}?k{sup ?}{sub 1}+k{sup ?}{sub 2} in a plasma, where k{sup ?}{sub 1} and k{sup ?}{sub 2} are wave vectors of lasers having frequencies ?{sub 1} and ?{sub 2}, respectively. The driven beat wave acts as a pump for SRS and excites parametrically a pair of plasma wave (?,k{sup ?}) and side band electromagnetic wave (?{sub 3},k{sup ?}{sub 3}) propagating in the sideward direction in such a way that momentum remains conserved. The growth rate of Raman process is maximum for side scattering at ?{sub s}=?/2 for lower values of applied magnetic field (?1?kG), which can be three fold by applying magnetic field ?5.0?kG. Thus, optimum value of magnetic field can be utilized to achieve maximum electron acceleration in counter propagating geometry of beat wave acceleration by reducing the growth rate of Raman process.

  20. Evaluation of Counter-Based Dynamic Load Balancing Schemes for Massive Contingency Analysis on Over 10,000 Cores

    SciTech Connect (OSTI)

    Chen, Yousu; Huang, Zhenyu; Rice, Mark J.

    2012-12-27T23:59:59.000Z

    Contingency analysis studies are necessary to assess the impact of possible power system component failures. The results of the contingency analysis are used to ensure the grid reliability, and in power market operation for the feasibility test of market solutions. Currently, these studies are performed in real time based on the current operating conditions of the grid with a set of pre-selected contingency list, which might result in overlooking some critical contingencies caused by variable system status. To have a complete picture of a power grid, more contingencies need to be studied to improve grid reliability. High-performance computing techniques hold the promise of being able to perform the analysis for more contingency cases within a much shorter time frame. This paper evaluates the performance of counter-based dynamic load balancing schemes for a massive contingency analysis program on 10,000+ cores. One million N-2 contingency analysis cases with a Western Electricity Coordinating Council power grid model have been used to demonstrate the performance. The speedup of 3964 with 4096 cores and 7877 with 10240 cores are obtained. This paper reports the performance of the load balancing scheme with a single counter and two counters, describes disk I/O issues, and discusses other potential techniques for further improving the performance.

  1. Generalized seniority with realistic interactions in open-shell nuclei

    E-Print Network [OSTI]

    M. A. Caprio; F. Q. Luo; K. Cai; Ch. Constantinou; V. Hellemans

    2014-08-30T23:59:59.000Z

    Generalized seniority provides a truncation scheme for the nuclear shell model, based on pairing correlations, which offers the possibility of dramatically reducing the dimensionality of the nuclear shell-model problem. Systematic comparisons against results obtained in the full shell-model space are required to assess the viability of this scheme. Here, we extend recent generalized seniority calculations for semimagic nuclei, the Ca isotopes, to open-shell nuclei, with both valence protons and valence neutrons. The even-mass Ti and Cr isotopes are treated in a full major shell and with realistic interactions, in the generalized seniority scheme with one broken proton pair and one broken neutron pair. Results for level energies, orbital occupations, and electromagnetic observables are compared with those obtained in the full shell-model space. We demonstrate that, even for the Ti isotopes, significant benefit would be obtained in going beyond the approximation of one broken pair of each type, while the Cr isotopes require further broken pairs to provide even qualitative accuracy.

  2. Coupling of (ultra-) relativistic atomic nuclei with photons

    SciTech Connect (OSTI)

    Apostol, M. [Institute of Atomic Physics, Institute for Physics and Nuclear Engineering, Magurele-Bucharest 077125, MG-6, POBox MG-35 (Romania)] [Institute of Atomic Physics, Institute for Physics and Nuclear Engineering, Magurele-Bucharest 077125, MG-6, POBox MG-35 (Romania); Ganciu, M. [National Institute for Lasers, Plasma and Radiation Physics, Magurele-Bucharest 077125, POBox MG-36 (Romania)] [National Institute for Lasers, Plasma and Radiation Physics, Magurele-Bucharest 077125, POBox MG-36 (Romania)

    2013-11-15T23:59:59.000Z

    The coupling of photons with (ultra-) relativistic atomic nuclei is presented in two particular circumstances: very high electromagnetic fields and very short photon pulses. We consider a typical situation where the (bare) nuclei (fully stripped of electrons) are accelerated to energies ? 1 TeV per nucleon (according to the state of the art at LHC, for instance) and photon sources like petawatt lasers ? 1 eV-radiation (envisaged by ELI-NP project, for instance), or free-electron laser ? 10 keV-radiation, or synchrotron sources, etc. In these circumstances the nuclear scale energy can be attained, with very high field intensities. In particular, we analyze the nuclear transitions induced by the radiation, including both one- and two-photon proceses, as well as the polarization-driven transitions which may lead to giant dipole resonances. The nuclear (electrical) polarization concept is introduced. It is shown that the perturbation theory for photo-nuclear reactions is applicable, although the field intensity is high, since the corresponding interaction energy is low and the interaction time (pulse duration) is short. It is also shown that the description of the giant nuclear dipole resonance requires the dynamics of the nuclear electrical polarization degrees of freedom.

  3. Delayed-fission properties of neutron-deficient americium nuclei

    SciTech Connect (OSTI)

    Hall, H.L. (California Univ., Berkeley, CA (USA). Dept. of Chemistry)

    1989-10-23T23:59:59.000Z

    Characteristics of the delayed-fission decay mode in light americium nuclei have been investigated. Measurements on the unknown isotopes {sup 230}Am and {sup 236}Am were attempted, and upper limits on the delayed-fission branches of these nuclei were determined. Evidence of the existence of {sup 236}Am was observed in radiochemical separations. Total kinetic energy and mass-yield distributions of the electron-capture delayed-fission mode were measured for {sup 232}Am (t{sub 1/2} = 1.31 {plus minus} 0.04 min) and for {sup 234}Am (t{sub 1/2} = 2.32 {plus minus} 0.08 min), and delayed-fission probabilities of 6.9 {times} 10{sup {minus}4} and 6.6 {times} 10{sup {minus}5}, respectively, were determined. The total kinetic energy and the asymmetric mass-yield distributions are typical of fission of mid-range actinides. No discernible influence of the anomalous triple-peaked mass division characteristic of the thorium-radium region was detected. Measurements of the time correlation between the electron-capture x-rays and the subsequent fission conform that the observed fissions arise from the electron-capture delayed-fission mechanism. Delayed fission has provided a unique opportunity to extend the range of low-energy fission studies to previously inaccessible regions. 71 refs., 44 figs., 13 tabs.

  4. Viability of nuclear $?$-particle condensates A reply to N.T. Zinner and A.S. Jensen, arXiv:nucl/th0712.1191

    E-Print Network [OSTI]

    Y. Funaki; H. Horiuchi; G. Roepke; P. Schuck; A. Tohsaki; T. Yamada; W. von Oertzen

    2008-05-16T23:59:59.000Z

    In a recent paper, arXiv0712.1191 [nucl-th], Zinner and Jensen (ZJ) expressed strong doubts about the concept of alpha-particle condensation in finite nuclei. In this article we give a reply which, essentially, is point by point (but not in the order).

  5. Ionization Cluster Size Distributions Created by Low Energy Electrons and Alpha Particles in Nanometric Track Segment in Gases

    E-Print Network [OSTI]

    Bantsar, Aliaksandr

    2012-01-01T23:59:59.000Z

    The interaction of ionizing radiation with nanometric targets is a field of interest for many branches of science such as: radiology, oncology, radiation protection and nanoelectronics. A new experimental technique known as nanodosimetry has been developed for the qualitative as well as quantitative description of these types of interactions. The work presented here is a contribution to this development, namely by further improvement of the new experimental technique called the Jet Counter, originally developed at the Andrzej So{\\l}tan Institute for Nuclear Studies. The Jet Counter is a unique device in the world for studying the interaction of low energy electrons with nanometer targets in the range 2-10 nm (in unit density). The basic experimental result is the frequency distribution of ionization cluster size produced by ionizing particles in a gaseous (nitrogen or propane) nanometric track segment. The first experimental data on the frequency distribution of ionization cluster size produced by low energy ...

  6. Instruction-Level Characterization of Scientific Computing Applications Using Hardware Performance Counters

    SciTech Connect (OSTI)

    Luo, Y.; Cameron, K.W.

    1998-11-24T23:59:59.000Z

    Workload characterization has been proven an essential tool to architecture design and performance evaluation in both scientific and commercial computing areas. Traditional workload characterization techniques include FLOPS rate, cache miss ratios, CPI (cycles per instruction or IPC, instructions per cycle) etc. With the complexity of sophisticated modern superscalar microprocessors, these traditional characterization techniques are not powerful enough to pinpoint the performance bottleneck of an application on a specific microprocessor. They are also incapable of immediately demonstrating the potential performance benefit of any architectural or functional improvement in a new processor design. To solve these problems, many people rely on simulators, which have substantial constraints especially on large-scale scientific computing applications. This paper presents a new technique of characterizing applications at the instruction level using hardware performance counters. It has the advantage of collecting instruction-level characteristics in a few runs virtually without overhead or slowdown. A variety of instruction counts can be utilized to calculate some average abstract workload parameters corresponding to microprocessor pipelines or functional units. Based on the microprocessor architectural constraints and these calculated abstract parameters, the architectural performance bottleneck for a specific application can be estimated. In particular, the analysis results can provide some insight to the problem that only a small percentage of processor peak performance can be achieved even for many very cache-friendly codes. Meanwhile, the bottleneck estimation can provide suggestions about viable architectural/functional improvement for certain workloads. Eventually, these abstract parameters can lead to the creation of an analytical microprocessor pipeline model and memory hierarchy model.

  7. ADVANCES IN THE RXTE PROPORTIONAL COUNTER ARRAY CALIBRATION: NEARING THE STATISTICAL LIMIT

    SciTech Connect (OSTI)

    Shaposhnikov, Nikolai [CRESST and Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Jahoda, Keith; Markwardt, Craig; Swank, Jean; Strohmayer, Tod, E-mail: nikolai.v.shaposhnikov@nasa.gov [Astrophysics Science Division, Goddard Space Flight Center, NASA, Greenbelt, MD 20771 (United States)

    2012-10-01T23:59:59.000Z

    During its 16 years of service, the Rossi X-Ray Timing Explorer (RXTE) mission has provided an extensive archive of data, which will serve as a primary source of high cadence observations of variable X-ray sources for fast timing studies. It is, therefore, very important to have the most reliable calibration of RXTE instruments. The Proportional Counter Array (PCA) is the primary instrument on board RXTE which provides data in 3-50 keV energy range with submillisecond time resolution in up to 256 energy channels. In 2009, the RXTE team revised the response residual minimization method used to derive the parameters of the PCA physical model. The procedure is based on the residual minimization between the model spectrum for Crab Nebula emission and a calibration data set consisting of a number of spectra from the Crab and the on-board Am{sub 241} calibration source, uniformly covering the whole RXTE mission operation period. The new method led to a much more effective model convergence and allowed for better understanding of the PCA energy-to-channel relationship. It greatly improved the response matrix performance. We describe the new version of the RXTE/PCA response generator PCARMF v11.7 (HEASOFT Release 6.7) along with the corresponding energy-to-channel conversion table (version e05v04) and their difference from the previous releases of PCA calibration. The new PCA response adequately represents the spectrum of the calibration sources and successfully predicts the energy of the narrow iron emission line in Cas-A throughout the RXTE mission.

  8. Charged particle accelerator grating

    DOE Patents [OSTI]

    Palmer, Robert B. (Shoreham, NY)

    1986-01-01T23:59:59.000Z

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  9. Entanglement of Accelerating Particles

    E-Print Network [OSTI]

    W. L. Ku; M. -C. Chu

    2007-09-03T23:59:59.000Z

    We study how the entanglement of a maximally entangled pair of particles is affected when one or both of the pair are uniformly accelerated, while the detector remains in an inertial frame. We find that the entanglement is unchanged if all degrees of freedom are considered. However, particle pairs are produced, and the entanglements of different bipartite systems may change with the acceleration. In particular, the entanglement between accelerating fermions is transferred preferentially to the produced antiparticles when the acceleration is large, and the entanglement transfer is complete when the acceleration approaches infinity. However, for scalar particles, no entanglement transfer to the antiparticles is observed.

  10. GRAVITATIONAL MODEL OF HIGH-ENERGY PARTICLES IN A COLLIMATED JET

    SciTech Connect (OSTI)

    De Freitas Pacheco, J. A. [University of Nice-Sophia Antipolis, Observatoire de la Cote d'Azur Laboratoire Lagrange, UMR 7293, BP 4229, F-06304 Nice Cedex 4 (France); Gariel, J.; Marcilhacy, G.; Santos, N. O., E-mail: pacheco@oca.eu, E-mail: jerome.gariel@upmc.fr, E-mail: gmarcilhacy@hotmail.com, E-mail: nilton.santos@upmc.fr [LERMA-UPMC, University Pierre and Marie Curie, Observatoire de Paris CNRS, UMR 8112, 3 rue de Galilee, F-94200 Ivry sur Seine (France)

    2012-11-10T23:59:59.000Z

    Observations suggest that relativistic particles play a fundamental role in the dynamics of jets emerging from active galactic nuclei as well as in their interaction with the intracluster medium. However, no general consensus exists concerning the acceleration mechanism of those high-energy particles. A gravitational acceleration mechanism is proposed here in which particles leaving precise regions within the ergosphere of a rotating supermassive black hole (BH) produce a highly collimated flow. These particles follow unbound geodesics which are asymptotically parallel to the spin axis of the BH and are characterized by the energy E, the Carter constant Q, and zero angular momentum of the component L{sub z} . If environmental effects are neglected, the present model predicts the presence of electrons with energies around 9.4 GeV at distances of about 140 kpc from the ergosphere. The present mechanism can also accelerate protons up to the highest energies observed in cosmic rays by the present experiments.

  11. OBSERVATIONS OF RECENT NEW PARTICLE FORMATION IN HOUSTON DURING TEXAQS-2000.

    SciTech Connect (OSTI)

    BUZORIUS,G.; BRECHTEL,F.; ZELENYUK,A.; IMRE,D.; ANGEVINE,W.M.

    2001-10-01T23:59:59.000Z

    Particle number size distribution measurements were conducted at a tall building site and on a research aircraft during the TexAQS-2000 study. High concentrations of nucleation mode particles were observed during the early morning hours at the same time as the top of the developing boundary layer reached the sampling altitude. Transport of primary emissions from traffic and other local sources, as well as secondary formation processes, was observed. Growth of particles from the nucleation to Aitken modes appears to significantly impact the observed diurnal variation in the number size distribution. As these particles grow to larger sizes they may become more effective at scattering radiation and could act as cloud condensation nuclei, resulting in visibility and climate effects.

  12. FISH and Chips: Automation of Fluorescent Dot Counting in Interphase Cell Nuclei

    E-Print Network [OSTI]

    van Vliet, Lucas J.

    ) in each cell nucleus. This system works with two fluorescent dyes, one for the DNA hybridization dotsFISH and Chips: Automation of Fluorescent Dot Counting in Interphase Cell Nuclei Hans Netten,1 Ian abnormalities in inter- phase cell nuclei. This process is called dot counting. To estimate the distribution

  13. Measuring the fusion of neutron-rich light nuclei at and below the

    E-Print Network [OSTI]

    de Souza, Romualdo T.

    of the crust, the Coulomb barrier is too high for thermonuclear fusion of carbon. A heat source, other thanMeasuring the fusion of neutron-rich light nuclei at and below the Coulomb barrier SYLVIE HUDAN August , 2012 #12;Fusion of neutron-rich light nuclei at and below the Coulomb barrierSylvie Hudan

  14. Nuclear Physics A 587 (1995) 787-801 (3He,t) reactions on unstable nuclei

    E-Print Network [OSTI]

    Fernández de Córdoba, Pedro

    ELSEVIER NUCLEAR PHYSICS A Nuclear Physics A 587 (1995) 787-801 (3He,t) reactions on unstable,t) reactions on unstable nuclei theoretically. Since this charge-exchange reaction takes place on the nuclear in nuclear physics since we got a new tool, "beams of unstable nuclei" [1,2]. Many experimentalists have

  15. Towards the critical behavior for the light nuclei by NIMROD detector

    E-Print Network [OSTI]

    Y. G. Ma; J. B. Natowitz; R. Wada; K. Hagel; J. Wang; T. Keutgen; Z. Majka; M. Murray; L. Qin; P. Smith; R. Alfaro; J. Cibor; M. Cinausero; Y. El Masri; D. Fabris; E. Fioretto; A. Keksis; M. Lunardon; A. Makeev; N. Marie; E. Martin; A. Martinez-Davalos; A. Menchaca-Rocha; G. Nebbia; G. Prete; V. Rizzi; A. Ruangma; D. V. Shetty; G. Souliotis; P. Staszel; M. Veselsky; G. Viesti; E. M. Winchester; S. J. Yennello

    2004-11-21T23:59:59.000Z

    The critical behavior for the light nuclei with A$\\sim 36$ has been investigated experimentally by the NIMROD multi-detectors. The wide variety of observables indicate the critical point has been reached in the disassembly of hot nuclei at an excitation energy of 5.6$\\pm$0.5 MeV/u.

  16. Photoproduction of mesons off light nuclei Department of Physics, University of Basel, Switzerland

    E-Print Network [OSTI]

    Krusche, Bernd

    nuclei was furthermore explored for the study of hadron in-medium properties and the interaction it is also used to study hadron in-medium properties and meson - nucleon interactions (see e.g. [1, 2, 3, 4 to the search for -mesic states in helium and lithium nuclei. Sixth International Conference on Quarks

  17. Delayed and In-beam Spectroscopy on Francium and Astatine Nuclei at the Proton Drip Line

    SciTech Connect (OSTI)

    Uusitalo, J.; Jakobsson, U. [Department of Physics, University of Jyvaeskylae (Finland); Collaboration: RITU-Gamma Gollaboration

    2011-11-30T23:59:59.000Z

    Delayed and in-beam spectroscopy on francium and astatine nuclei at and beyond the proton drip line has been performed. In neutron deficient astatine nuclei a shift to deformed shapes as a function of decreasing neutron has been obtained. In neutron deficient francium isotope the same shift is evident.

  18. SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS

    E-Print Network [OSTI]

    Boyer, Edmond

    L-263 SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS vu par les noyaux. Abstract. - The spin-dependent scattering length of slow neutrons by the nuclei 23 can be of practical importance in many thermal neutron scattering experiments. A new method, called

  19. The neutron drip line: single-particle degrees of freedom and pairing properties as sources of theoretical uncertainties

    E-Print Network [OSTI]

    A. V. Afanasjev; S. E. Agbemava; D. Ray; P. Ray

    2015-01-17T23:59:59.000Z

    The sources of theoretical uncertainties in the prediction of the two-neutron drip line are analyzed in the framework of covariant density functional theory. We concentrate on single-particle and pairing properties as potential sources of these uncertainties. The major source of these uncertainties can be traced back to the differences in the underlying single-particle structure of the various covariant energy density functionals (CEDF). It is found that the uncertainties in the description of single-particle energies at the two-neutron drip line are dominated by those existing already in known nuclei. Only approximately one third of these uncertainties are due to the uncertainties in the isovector channel of CEDF's. Thus, improving the CEDF description of single-particle energies in known nuclei will also reduce the uncertainties in the prediction of the position of two-neutron drip line. The predictions of pairing properties in neutron rich nuclei depend on the CEDF. Although pairing properties affect moderately the position of the two-neutron drip line they represent only a secondary source for the uncertainties in the definition of the position of the two-neutron drip line.

  20. Big Bang Day: 5 Particles - 5. The Next Particle

    ScienceCinema (OSTI)

    None

    2011-04-25T23:59:59.000Z

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.

  1. Volumetric particle modeling 

    E-Print Network [OSTI]

    Dingle, Brent Michael

    2007-09-17T23:59:59.000Z

    This dissertation presents a robust method of modeling objects and forces for computer animation. Within this method objects and forces are represented as particles. As in most modeling systems, the movement of objects is driven by physically based...

  2. Elementary particle theory

    SciTech Connect (OSTI)

    Marciano, W.J.

    1984-12-01T23:59:59.000Z

    The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references. (WHK)

  3. Research in particle theory

    SciTech Connect (OSTI)

    Mansouri, F.; Suranyi, P; Wijewardhana, L.C.R.

    1991-10-01T23:59:59.000Z

    In the test particle approximation, the scattering amplitude for two-particle scattering in (2+1)-dimensional Chern-Simons-Witten gravity and supergravity was computed and compared to the corresponding metric solutions. The formalism was then extended to the exact gauge theoretic treatment of the two-particle scattering problem and compared to 't Hooft's results from the metric approach. We have studied dynamical symmetry breaking in 2+1 dimensional field theories. We have analyzed strong Extended Technicolor (ETC) models where the ETC coupling is close to a critical value. There are effective scalar fields in each of the theories. We have worked our how such scalar particles can be produced and how they decay. The {phi}{sup 4} field theory was investigated in the Schrodinger representation. The critical behavior was extracted in an arbitrary number of dimensions in second order of a systematic truncation approximation. The correlation exponent agrees with known values within a few percent.

  4. Accelerating Particles with Plasma

    SciTech Connect (OSTI)

    Litos, Michael; Hogan, Mark

    2014-11-05T23:59:59.000Z

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  5. Particle deposition in ventilation ducts

    E-Print Network [OSTI]

    Sippola, Mark R.

    2002-01-01T23:59:59.000Z

    were observed to lead to resuspension of particles in thethe nozzles may lead to resuspension of deposited particles.resuspension, the decreased response to turbulent velocity fluctuations of the very large particles should lead

  6. Photodisintegration studies on p-nuclei: The case of Mo and Sm isotopes

    E-Print Network [OSTI]

    C. Nair; A. R. Junghans; M. Erhard; D. Bemmerer; R. Beyer; P. Crespo; E. Grosse; M. Fauth; K. Kosev; G. Rusev; K. D. Schilling; R. Schwengner; A. Wagner

    2007-10-26T23:59:59.000Z

    In explosive stellar environments like supernovae, the temperatures are high enough for the production of heavy neutron-deficient nuclei, the socalled p-nuclei. Up to now, the knowledge of the reaction rates of p-nuclei is based on theoretical parameterizations using statistical model calculations. At the bremsstrahlung facility of the superconducting electron accelerator ELBE of FZ Dresden-Rossendorf, we aim to measure the photodisintegration rates of heavy nuclei experimentally. Photoactivation measurements on the astrophysically relevant p-nuclei 92Mo and 144Sm have been performed with bremsstrahlung end-point energies from 10.0 to 16.5 MeV. First experiments on the short-lived decays following the reaction 144Sm(gamma,n) are carried out using a pneumatic delivery system for rapid transport of activated samples. The activation yields are compared with calculations using cross sections from recent Hauser-Feshbach models.

  7. ELEMENTARY PARTICLE INTERACTIONS

    SciTech Connect (OSTI)

    EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

    2013-07-30T23:59:59.000Z

    The High-Energy Elementary Particle Interactions group at UT during the last three years worked on the following directions and projects: Collider-based Particle Physics; Neutrino Physics, particularly participation in “NO?A”, “Double Chooz”, and “KamLAND” neutrino experiments; and Theory, including Scattering amplitudes, Quark-gluon plasma; Holographic cosmology; Holographic superconductors; Charge density waves; Striped superconductors; and Holographic FFLO states.

  8. Symmetries of particle motion

    E-Print Network [OSTI]

    Roy Maartens; David Taylor

    1997-12-11T23:59:59.000Z

    We define affine transport lifts on the tangent bundle by associating a transport rule for tangent vectors with a vector field on the base manifold. The aim is to develop tools for the study of kinetic/ dynamical symmetries in relativistic particle motion. The transport lift unifies and generalises the various existing lifted vector fields, with clear geometric interpretations. We find the affine dynamical symmetries of free particle motion, and compare this to previous results and to the alternative concept of "matter symmetry".

  9. Safe biodegradable fluorescent particles

    DOE Patents [OSTI]

    Martin, Sue I. (Berkeley, CA); Fergenson, David P. (Alamo, CA); Srivastava, Abneesh (Santa Clara, CA); Bogan, Michael J. (Dublin, CA); Riot, Vincent J. (Oakland, CA); Frank, Matthias (Oakland, CA)

    2010-08-24T23:59:59.000Z

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  10. Dark matter particles

    E-Print Network [OSTI]

    V. Berezinsky

    1996-10-31T23:59:59.000Z

    The baryonic and cold dark matter are reviewed in the context of cosmological models. The theoretical search for the particle candidates is limited by supersymmetric extension of the Standard Model. Generically in such models there are just two candidates associated with each other: generalized neutralino, which components are usual neutralino and axino, and axion which is a partner of axino in supermultiplet. The status of these particles as DM candidates is described.

  11. PARTICLES OF DIFFERENCE.

    SciTech Connect (OSTI)

    SCHWARTZ,S.E.

    2000-09-21T23:59:59.000Z

    It is no longer appropriate, if it ever was, to think of atmospheric aerosols as homogeneous spheres of uniform composition and size. Within the United States, and even more globally, not only the mass loading but also the composition, morphology, and size distribution of atmospheric aerosols are highly variable, as a function of location, and at a given location as a function of time. Particles of a given aerodynamic size may differ from one another, and even within individual particles material may be inhomogeneously distributed, as for example, carbon spherules imbedded in much larger sulfate particles. Some of the particulate matter is primary, that is, introduced into the atmosphere directly as particles, such as carbon particles in diesel exhaust. Some is secondary, that is, formed in the atmosphere by gas-to-particle conversion. Much of the material is inorganic, mainly sulfates and nitrates resulting mainly from energy-related emissions. Some of the material is carbonaceous, in part primary, in part secondary, and of this material some is anthropogenic and some biogenic. While the heterogeneity of atmospheric aerosols complicates the problem of understanding their loading and distribution, it may well be the key to its solution. By detailed examination of the materials comprising aerosols it is possible to infer the sources of these materials. It may be possible as well to identify specific health impairing agents. The heterogeneity of aerosol particles is thus the key to identifying their sources, to understanding the processes that govern their loading and properties, and to devising control strategies that are both effective and efficient. Future research must therefore take cognizance of differences among aerosol particles and use these differences to advantage.

  12. The ABC's of Atomic Nuclei: The Modern Alchemist

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8 Shell model: Nucleons occupy shell-like orbits inside nucleus; proposed by Maria Meyer & Hans Jensen in 1949 to explain the magic numbers and the single-particle...

  13. Ice particle size matters | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ice particle size matters Ice particle size matters Released: May 04, 2014 Fine-tuning cloud models for improved climate predictions The Science Arctic clouds are widespread and...

  14. Nuclear physics: from properties of atomic nuclei to medicine / Fizyka jadrowa: od wlasnosci jadra atomowego po medycyne.

    E-Print Network [OSTI]

    CERN. Geneva

    2012-01-01T23:59:59.000Z

    Nuclear physics: from properties of atomic nuclei to medicine / Fizyka jadrowa: od wlasnosci jadra atomowego po medycyne.

  15. Properties of rotational bands at the spin limit in A $\\sim$ 50, A $\\sim$ 65 and A $\\sim$ 110 nuclei

    E-Print Network [OSTI]

    Janzen, V P; Andrews, H R; Ball, G C; Cameron, J A; Cromaz, M; DeGraaf, J; Flibotte, S; Galindo-Uribarri, A; Hackman, G; Headly, D M; Jonkman, J; Mullins, S M; Radford, D C; Ragnarsson, I; Rodríguez, J L; Svensson, C E; Waddington, J C; Ward, D; Zwartz, G

    1996-01-01T23:59:59.000Z

    Properties of rotational bands at the spin limit in A $\\sim$ 50, A $\\sim$ 65 and A $\\sim$ 110 nuclei

  16. Powerful Outflows and Feedback from Active Galactic Nuclei

    E-Print Network [OSTI]

    King, Andrew

    2015-01-01T23:59:59.000Z

    Active Galactic Nuclei (AGN) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities $\\sim 0.1- 0.2c$ are a common feature in X--ray spectra of luminous AGN, offering a plausible physical origin for the well known connections between the hole and properties of its host. Observability constraints suggest that the winds must be episodic, and detectable only for a few percent of their lifetimes. The most powerful wind feedback, establishing the $M -\\sigma$ relation, is probably not directly observable at all. The $M - \\sigma$ relation signals a global change in the nature of AGN feedback. At black hole masses below $M-\\sigma$ feedback is confined to the immediate vicinity of the hole. At the $M-\\sigma$ mass it becomes much more energetic and widespread, and can drive away much of the bulge gas as a fast molecular outflow.

  17. Quantum Monte Carlo Calculations of Light Nuclei Using Chiral Potentials

    E-Print Network [OSTI]

    J. E. Lynn; J. Carlson; E. Epelbaum; S. Gandolfi; A. Gezerlis; A. Schwenk

    2014-11-09T23:59:59.000Z

    We present the first Green's function Monte Carlo calculations of light nuclei with nuclear interactions derived from chiral effective field theory up to next-to-next-to-leading order. Up to this order, the interactions can be constructed in a local form and are therefore amenable to quantum Monte Carlo calculations. We demonstrate a systematic improvement with each order for the binding energies of $A=3$ and $A=4$ systems. We also carry out the first few-body tests to study perturbative expansions of chiral potentials at different orders, finding that higher-order corrections are more perturbative for softer interactions. Our results confirm the necessity of a three-body force for correct reproduction of experimental binding energies and radii, and pave the way for studying few- and many-nucleon systems using quantum Monte Carlo methods with chiral interactions.

  18. Systematic study of iodine nuclei in A?125 mass region

    SciTech Connect (OSTI)

    Sharma, H. P.; Chakraborty, S.; Kumar, A. [Department of Physics, Banaras Hindu University, Varanasi-221005 (India); Banerjee, P. [Division of Nuclear Physics, Saha Institute of Nuclear Physics, Kolkata-700064 (India); Ganguly, S. [Department of Physics, Chandernagore College, Chandannagar-721136 (India); Muralithar, S.; Singh, R. P. [Inter University Accelerator Center, New Delhi-110067 (India); Kumar, A.; Kaur, N. [Department of Physics, Punjab University, Chandigarh-160014 (India); Kumar, S. [Department of Physics and Astrophysics, University of Delhi, New Delhi-110067 (India); Chaturvedi, L. [Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Bilaspur-495009 (India); Jain, A. K. [Department of Physics, Indian Institute of Technology, Roorkee-247667 (India); Laxminarayan, S. [Department of Physics, Andhra University, Visakhapatnam-530003 (India)

    2014-08-14T23:59:59.000Z

    Excited states of {sup 127}I were populated via {sup 124}Sn({sup 7}Li,{sup 4}n?){sup 127}I fusion-evaporation reaction at beam energy of 33 MeV. Multipolarities of several transitions were determined and spins of corresponding states have been confirmed. The band-head spin and parity of an already reported band at 2901.2 keV has been confirmed. Based on the observed characteristic features and by comparing with the systematics of odd mass iodine nuclei, a ?g{sub 7/2}??h{sub 11/2}{sup 2} configuration has been proposed for this band. The experimental B(M1)/B(E2) values for ?g{sub 7/2} band were compared with the theoretical results of semi classical model of Frauendorf and Donau and found in well agreement.

  19. Multifragmentation at the balance energy of mass asymmetric colliding nuclei

    E-Print Network [OSTI]

    Supriya Goyal

    2011-06-20T23:59:59.000Z

    Using the quantum molecular dynamics model, we study the role of mass asymmetry of colliding nuclei on the fragmentation at the balance energy and on its mass dependence. The study is done by keeping the total mass of the system fixed as 40, 80, 160, and 240 and by varying the mass asymmetry of the ($\\eta$ = $\\frac{A_{T}-A_{P}}{A_{T}+A_{P}}$; where $A_{T}$ and $A_{P}$ are the masses of the target and projectile, respectively) reaction from 0.1 to 0.7. Our results clearly indicate a sizeable effect of the mass asymmetry on the multiplicity of various fragments. The mass asymmetry dependence of various fragments is found to increase with increase in total system mass (except for heavy mass fragments). Similar to symmetric reactions, a power law system mass dependence of various fragment multiplicities is also found to exit for large asymmetries.

  20. Modelling the polarization dichotomy of Active Galactic Nuclei

    E-Print Network [OSTI]

    Rene W. Goosmann

    2007-12-12T23:59:59.000Z

    I present polarization modelling of Active Galactic Nuclei in the optical/UV range. The modelling is conducted using the Monte-Carlo radiative transfer code Stokes, which self-consistently models the polarization signature of a complex model arrangement for an active nucleus. In this work I include three different scattering regions around the central source: an equatorial electron scattering disk, an equatorial obscuring dusty torus, and polar electron scattering cones. I investigate the resulting dependencies of the V-band polarization for different optical depths of the scattering cones, different dust compositions inside the torus, and various half-opening angles of the torus/polar cones. The observed polarization dichotomy can be successfully reproduced by the model.