Powered by Deep Web Technologies
Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Condensation Particle Counter  

E-Print Network [OSTI]

Model 3007 Condensation Particle Counter Operation and Service Manual 1930035, Revision C August 2002 P a r t i c l e I n s t r u m e n t s #12;#12;Model 3007 Condensation Particle Counter Operation............................................................................V 1. UNPACKING AND PARTS IDENTIFICATION..................................1 Unpacking the Condensation

Weber, Rodney

2

Rapid Scan Humidified Growth Cloud Condensation Nuclei Counter  

SciTech Connect (OSTI)

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.

Gregory L. Kok; Athanasios Nenes

2013-03-13T23:59:59.000Z

3

of the filter were measured using condensation particle counters (TSI Inc. model 3022A). Submicrometer particles entering the counters are  

E-Print Network [OSTI]

Standard for High Efficiency Air Filters (HEPA and ULPA), Beuth Verlag GmbH, Berlin, Germany 1995. [11] Tof the filter were measured using condensation particle counters (TSI Inc. model 3022A). Submicrometer particles entering the counters are grown into micrometer sized droplets by condensation

Gruner, George

4

High Resolution Particle Beam Monitoring and Ionization Counters with the Help of Single Carbon Nanotubes  

E-Print Network [OSTI]

After a short review of modern beam monitors, ionization and proportional counters and discussion on the necessity to have thinner wires, we propose and consider construction and parameters of nanotube particle beam monitors and counters

K. A. Ispirian; R. K. Ispiryan; A. T. Margarian

2009-08-18T23:59:59.000Z

5

Particle-hole symmetry parameters for nuclei  

E-Print Network [OSTI]

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.

Ian Bentley

2015-03-10T23:59:59.000Z

6

Single-particle states in transcurium nuclei.  

SciTech Connect (OSTI)

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.

Ahmad, I.

1999-09-30T23:59:59.000Z

7

Electrical Mobility Spectrometer Using a Diethylene Glycol Condensation Particle Counter for Measurement of Aerosol Size Distributions Down to 1 nm  

SciTech Connect (OSTI)

We report a new scanning mobility particle spectrometer (SMPS) for measuring number size distributions of particles down to {approx}1 nm mobility diameter. This SMPS includes an aerosol charger, a TSI 3085 nano differential mobility analyzer (nanoDMA), an ultrafine condensation particle counter (UCPC) using diethylene glycol (DEG) as the working fluid, and a conventional butanol CPC (the 'booster') to detect the small droplets leaving the DEG UCPC. The response of the DEG UCPC to negatively charged sodium chloride particles with mobility diameters ranging from 1-6 nm was measured. The sensitivity of the DEG UCPC to particle composition was also studied by comparing its response to positively charged 1.47 and 1.70 nm tetra-alkyl ammonium ions, sodium chloride, and silver particles. A high resolution differential mobility analyzer was used to generate the test particles. These results show that the response of this UCPC to sub-2 nm particles is sensitive to particle composition. The applicability of the new SMPS for atmospheric measurement was demonstrated during the Nucleation and Cloud Condensation Nuclei (NCCN) field campaign (Atlanta, Georgia, summer 2009). We operated the instrument at saturator and condenser temperatures that allowed the efficient detection of sodium chloride particles but not of air ions having the same mobility. We found that particles as small as 1 nm were detected during nucleation events but not at other times. Factors affecting size distribution measurements, including aerosol charging in the 1-10 nm size range, are discussed. For the charger used in this study, bipolar charging was found to be more effective for sub-2 nm particles than unipolar charging. No ion induced nucleation inside the charger was observed during the NCCN campaign.

Jiang, J.; Kuang, C.; Chen, M.; Attoui, M.; McMurry, P. H.

2011-02-01T23:59:59.000Z

8

Use of nuclei fractal properties for help to determine some unknown particle spins and unknown nuclei excited level spins  

E-Print Network [OSTI]

The fractal property stipulates that the same physical laws apply for different scales of a given physics. This property is applied to particles and nuclei, in order to study the possibility to use it to help for determination of unknown spins of some particles or excited nuclei levels.

Boris Tatischeff

2011-12-06T23:59:59.000Z

9

Ice Nuclei in Marine Air: Biogenic Particles or Dust?  

SciTech Connect (OSTI)

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.

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

2013-01-11T23:59:59.000Z

10

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

E-Print Network [OSTI]

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.

K. P. Santhosh; B. Priyanka

2014-04-02T23:59:59.000Z

11

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

E-Print Network [OSTI]

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.

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

2014-04-04T23:59:59.000Z

12

Single particle states in the heaviest known nuclei  

SciTech Connect (OSTI)

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.

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

13

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

E-Print Network [OSTI]

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.

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

2009-08-06T23:59:59.000Z

14

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

SciTech Connect (OSTI)

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.

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

15

Inelastic Interactions of Proton with Emulsion Nuclei without Shower Particle Creation  

SciTech Connect (OSTI)

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.

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

16

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

E-Print Network [OSTI]

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.

T. Duguet; G. Hagen

2012-04-11T23:59:59.000Z

17

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

E-Print Network [OSTI]

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%.

G. K. Nie

2011-06-21T23:59:59.000Z

18

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

E-Print Network [OSTI]

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.

Niu, Yifei; Colo, Gianluca; Vigezzi, Enrico

2015-01-01T23:59:59.000Z

19

Detection of Minimum-Ionizing Particles and Nuclear Counter Effect with Pure BGO and BSO Crystals with Photodiode Read-out  

E-Print Network [OSTI]

Long BGO (Bismuth Germanate) and BSO (Bismuth Silicate) crystals coupled with silicon photodiodes have been used to detect minimum-ionizing particles(MIP). With a low noise amplifier customized for this purpose, the crystals can detect MIPs with an excellent signal-to-noise ratio. The NCE(Nuclear Counter Effect} is also clearly observed and measured. Effect of full and partial wrapping of a reflector around the crystal on light collection is also studied.

K. Ueno; S. K. Sahu; K. C. Peng; W. S. Hou; C. H. Wang

1997-04-11T23:59:59.000Z

20

Examinations of ice formation processes in Florida cumuli using ice nuclei measurements of anvil ice crystal particle residues  

E-Print Network [OSTI]

importance of different ice formation processes in cumuli and the cirrus anvils they produce. Cirrus playExaminations of ice formation processes in Florida cumuli using ice nuclei measurements of anvil ice crystal particle residues Anthony J. Prenni,1 Paul J. DeMott,1 Cynthia Twohy,2 Michael R. Poellot

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

SciTech Connect (OSTI)

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.

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

22

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

E-Print Network [OSTI]

by the HiVol/Coulter process. The HiVol/Coulter process includes the determination of the percent of particles less than 10 um (AED) on a total suspended particulate matter filter. Representative particle size distributions were obtained for cotton dust... with an aerodynamic equivalent diameter (AED) larger than 10 micrometers (um) were seldom found in the air spaces of the lungs, Particles larger than 10 um (AED) do not pass the filtering mechanisms of the respiratory tract and are of less concern (AMA, 1963...

Herber, Douglas John

2012-06-07T23:59:59.000Z

23

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)

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.

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

24

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)

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.

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

25

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

E-Print Network [OSTI]

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.

Marco Brenna

2014-08-01T23:59:59.000Z

26

Distributed performance counters  

DOE Patents [OSTI]

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.

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

2013-11-26T23:59:59.000Z

27

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

SciTech Connect (OSTI)

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.

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

28

Photons into axion-like particles conversion in Active Galactic Nuclei  

E-Print Network [OSTI]

The idea that photons can convert into axion-like particles (ALPs) $\\gamma \\to a$ in or around an AGN and reconvert back into photons $a \\to \\gamma$ in the Milky Way magnetic field has been put forward in 2008 and has recently attracted growing interest. Yet, so far nobody has estimated the conversion probability $\\gamma \\to a$ as carefully as allowed by present-day knowledge. Our aim is to fill this gap. We first remark that AGN that can be detected above 100 GeV are blazars, namely AGN with jets, with one of them pointing towards us. Moreover, blazars fall into two well defined classes: BL Lac objects (BL Lacs) and Flat Spectrum Radio Quasars (FSRQs), with drastically different properties. In this Letter we evaluate the $\\gamma \\to a$ conversion probability inside these two classes of blazars, taking also the host elliptical galaxy into account. Our findings are surprising. For, while in the case of BL Lacs the conversion probability turns out to be totally unpredictable due to the strong dependence on the values of the somewhat uncertain position of the emission region along the jet and strength of the magnetic field therein, for FSRQs we are able to make a clear-cut prediction. Our results are of paramount importance in view of the planned very-high-energy detectors like the CTA, HAWK and HISCORE, as well as for laboratory experiments like ALPS II at DESY and IAXO.

Fabrizio Tavecchio; Marco Roncadelli; Giorgio Galanti

2014-06-09T23:59:59.000Z

29

Development of a Mobile Ice Nucleus Counter  

SciTech Connect (OSTI)

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.

Kok, Gregory; Kulkarni, Gourihar

2014-07-10T23:59:59.000Z

30

Pyrochemical multiplicity counter development  

SciTech Connect (OSTI)

Impure plutonium-bearing materials from pyrochemical processes often display both significant self-multiplication and variable ({alpha},n) reaction rates. Standard neutron coincidence counting techniques usually fail to accurately measure these materials. Neutron multiplicity counters measure the third moment of the neutron multiplicity distribution and thus make it possible to deduce the fertile plutonium mass of a sample even when both the self-multiplication and the ({alpha},n) reaction rate are unknown. A multiplicity counter suitable for measuring pyrochemical materials has been designed and built. This paper describes the results of characterization studies for the new counter. The counter consists of 126 helium-3 tubes arranged in 4 concentric rings in a polyethylene moderator; the average spacing between the tubes is 1.59 cm. The end plugs for the counter are made of graphite, and the 24.1- by 37.5-cm sample cavity is cadmium lined. The counter consists of two distinct halves from which the neutron counts are summed. The counter is capable of operation in either a freestanding mode with the two halves coupled together by an external cabinet or in a glove-box mode with the two halves placed around a glovebox well and then mated. For a {sup 252}Cf source centered in the sample cavity, the measured efficiency of the new multiplicity counter is 57.7% and its die-away time is 47.2{mu}s. 8 refs., 9 figs.

Langner, D.G.; Dytlewski, N.; Krick, M.S.

1991-01-01T23:59:59.000Z

31

Laboratory Eleven Simplified Counter  

E-Print Network [OSTI]

-to-low transition. The decade (BCD) count sequence is illustrated on Page 3 of the Data Sheets. However, you VHDL code for this module as an asynchronous sequential circuit. The detailed specifications are given for the counter outputs to test the performance of your circuit. iv. Revise your VHDL code to use a push button

Grantner, Janos L.

32

Acne treatments (over-the-counter) Acupuncture  

E-Print Network [OSTI]

-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

Bordenstein, Seth

33

Neutron counter based on beryllium activation  

SciTech Connect (OSTI)

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.

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

34

Leak Testing the DMT Cloud Condensation Nuclei Counter for  

E-Print Network [OSTI]

Saudi Arabia field project was funded by the Kingdom of Saudi Arabia through a contract with Weather housing. Don't try to tighten the metal fitting on the pump housing. #12;Hard Places to Find Leaks Saudi Operator Manual Rev D page 45. March 22, 2009 Saudi Arabia Down to 450 mb, climb to 500 mb took 311 seconds

Delene, David J.

35

Low latency counter event indication  

DOE Patents [OSTI]

A hybrid counter array device for counting events with interrupt indication includes a first counter portion comprising N counter devices, each for counting signals representing event occurrences and providing a first count value representing lower order bits. An overflow bit device associated with each respective counter device is additionally set in response to an overflow condition. 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. An operatively coupled control device monitors each associated overflow bit device and initiates incrementing a second count value stored at a corresponding memory location in response to a respective overflow bit being set. The incremented second count value is compared to an interrupt threshold value stored in a threshold register, and, when the second counter value is equal to the interrupt threshold value, a corresponding "interrupt arm" bit is set to enable a fast interrupt indication. On a subsequent roll-over of the lower bits of that counter, the interrupt will be fired.

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

2010-08-24T23:59:59.000Z

36

Space and power efficient hybrid counters array  

DOE Patents [OSTI]

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.

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

2010-03-30T23:59:59.000Z

37

The development of a planar multiwire proportional counter  

E-Print Network [OSTI]

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...

Hensley, John Richard

1970-01-01T23:59:59.000Z

38

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

E-Print Network [OSTI]

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.

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

39

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

E-Print Network [OSTI]

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.

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

40

Alternatives for Helium-3 in Multiplicity Counters  

SciTech Connect (OSTI)

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.

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

2013-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

E-Print Network [OSTI]

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

Collins, Gary S.

42

The Assembly of the Belle II TOP Counter  

E-Print Network [OSTI]

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.

Wang, Boqun

2015-01-01T23:59:59.000Z

43

The Assembly of the Belle II TOP Counter  

E-Print Network [OSTI]

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.

Boqun Wang; for the Belle II PID Group

2015-01-13T23:59:59.000Z

44

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

E-Print Network [OSTI]

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...

Wang, Xudong

2009-05-15T23:59:59.000Z

45

Understanding nuclei in the upper sd - shell  

SciTech Connect (OSTI)

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.

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

46

Structure and spectroscopy of transcurium nuclei.  

SciTech Connect (OSTI)

The stability of the superheavy elements depends on the shell corrections which are governed by the single-particle spectra. Ideally one would like to experimentally determine the single-particle levels in the superheavy nuclei but the production of only a few atoms of these nuclides precludes such measurements. One therefore has to identify single-particle levels in the heaviest nuclei which are available in at least nanoCurie amounts. They have studied the structure of such heavy nuclei in the Z=98 region and identified many single-particle states. In particular, they have studied the structure of {sup 251}Cf and {sup 249}Bk by measuring the radiations emitted in the {alpha} decay of {sup 255}Fm and {sup 253}Es. These single-particle spectra can be used to test theoretical models for superheavy elements.

Ahmad, I.

2001-11-09T23:59:59.000Z

47

Aerogel Cerenkov Counter for the BELLE Experiment  

E-Print Network [OSTI]

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...

Iijima Adachi; Belle Preprint

48

Basic Research Needs for Countering Terrorism  

SciTech Connect (OSTI)

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

Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; David 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

49

Countering Nuclear Terrorism and Trafficking | National Nuclear...  

National Nuclear Security Administration (NNSA)

Countering Nuclear Terrorism and Trafficking | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...

50

Separating Cloud Forming Nuclei from Interstitial Aerosol  

SciTech Connect (OSTI)

It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice clouds. The data is urgently needed to better represent the aerosol-cloud interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as cloud condensation nuclei (CCN) and ice nuclei (IN), termed as cloud nuclei (CN) henceforth, have become imperative in studying aerosol effects on clouds and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.

Kulkarni, Gourihar R.

2012-09-12T23:59:59.000Z

51

Monte-Carlo Simulation for an Aerogel Cherenkov Counter  

E-Print Network [OSTI]

We have developed a Monte-Carlo simulation code for an aerogel \\v Cerenkov Counter which is operated under a strong magnetic field such as 1.5T. This code consists of two parts: photon transportation inside aerogel tiles, and one-dimensional amplification in a fine-mesh photomultiplier tube. It simulates the output photoelectron yields as accurately as 5% with only a single free parameter. This code is applied to simulations for a B-Factory particle-identification system.

Ryuji Suda et al

1997-07-31T23:59:59.000Z

52

Boron-10 Lined Proportional Counter Wall Effects  

SciTech Connect (OSTI)

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.

Siciliano, Edward R.; Kouzes, Richard T.

2012-05-01T23:59:59.000Z

53

Low Power Front-End Electronics for the BESS-Polar Time-of-Flight Counter and Aerogel Cherenkov Counter  

E-Print Network [OSTI]

Low Power Front-End Electronics for the BESS-Polar Time-of-Flight Counter and Aerogel Cherenkov Counter

Sasaki, M

2005-01-01T23:59:59.000Z

54

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]

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.

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

2013-10-26T23:59:59.000Z

55

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]

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...

Xu, Yi; Goriely, Stephane; Arnould, Marcel; Ohta, Masahisa; Utsunomiya, Hiroaki

2013-01-01T23:59:59.000Z

56

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

E-Print Network [OSTI]

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

Friedman, B.

57

Cirrus cloud formation and the role of heterogeneous ice nuclei  

E-Print Network [OSTI]

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 ...

Froyd, Karl D.

2013-01-01T23:59:59.000Z

58

Isovector pairing and quartet condensation in N=Z nuclei  

SciTech Connect (OSTI)

We introduce and study a quartet condensate model (QCM) to treat the isovector pairing correlations in N=Z nuclei, by conserving the particle number and the total spin and isospin in the ground state of such nuclei. For the calculations we choose different isovector pairing forces acting on spherical and axially deformed single particle states. The results show that the QCM model describes very well the isovector pairing correlations for nuclear systems with N=Z.

Sandulescu, N.; Negrea, D.; Dukelsky, J.; Johnson, C. W. [National Institute of Physics and Nuclear Engineering, P.O. BOX MG-6, 76900 Bucharest-Magurele (Romania); Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain); Department of Physics, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1233 (United States)

2012-11-20T23:59:59.000Z

59

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,...

60

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

E-Print Network [OSTI]

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.

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

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

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

E-Print Network [OSTI]

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.

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

62

Identification of high transverse-momentum hadrons with a ring-imaging Cerenkov counter  

SciTech Connect (OSTI)

We have constructed and operated a large aperture ring-imaging Cerenkov counter in a high transverse-momentum experiment at Fermilab. We used multistep proportional chambers with a He/TEA photosensitive gas mixture to observe approximately 3.5 photons per relativistic particle. Hadron identification is obtained with good efficiency from threshold to 250 GeV/c.

Glass, H.; Adams, M.; Charpak, G.; Coutrakon, G.; Finley, D.; Hubbard, J.R.; Jaffe, D.; Kirz, J.; Mangeot, P.; McCarthy, R.; Peisert, A.

1985-02-01T23:59:59.000Z

63

New charge radius relations for atomic nuclei  

E-Print Network [OSTI]

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.

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

2014-11-24T23:59:59.000Z

64

Aquatic manoeuvering with counter-propagating waves: a novel  

E-Print Network [OSTI]

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

Lauder, George V.

65

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

E-Print Network [OSTI]

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

Collett Jr., Jeffrey L.

66

EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH European Laboratory for Particle Physics  

E-Print Network [OSTI]

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

Boyer, Edmond

67

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

SciTech Connect (OSTI)

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.

Fisch, N.J.; Shvets, G.

1998-08-01T23:59:59.000Z

68

Two and three nucleon K- absorption in nuclei  

E-Print Network [OSTI]

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.

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

2010-03-24T23:59:59.000Z

69

The AMS-01 Aerogel Threshold Cherenkov counter  

E-Print Network [OSTI]

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.

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

70

The decay of hot nuclei  

SciTech Connect (OSTI)

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.

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

1988-11-01T23:59:59.000Z

71

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

E-Print Network [OSTI]

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 ...

Vincent de Paul, Jegan Joyston

2009-01-01T23:59:59.000Z

72

Countering Improvised Explosive Devices: NPS and USMC Innovations  

E-Print Network [OSTI]

, as well as USMC and USN students, is dedicated to advancing counter-IED protection. The team's prior in protecting convoy operations, there is a need for devel- oping systems which can counter convoy-directed RC- IED attacks. The need for a long-term look at the counter-IED prob- lem is unfortunately self

73

Boron-10 Lined Proportional Counter Model Validation  

SciTech Connect (OSTI)

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 the development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube-based alternative system in the configuration of a coincidence counter. This report discusses the validation studies performed to establish the degree of accuracy of the computer modeling methods current used to simulate the response of boron-lined tubes. This is the precursor to developing models for the uranium neutron coincidence collar under Task 2 of this project.

Lintereur, Azaree T.; Siciliano, Edward R.; Kouzes, Richard T.

2012-06-30T23:59:59.000Z

74

Modeling level structures of odd-odd deformed nuclei  

SciTech Connect (OSTI)

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.

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

1984-09-07T23:59:59.000Z

75

CLOUD CONDENSATION NUCLEI IN CUMULUS HUMILIS SELECTED CASE STUDY DURING THE CHAPS CAMPAIGN  

E-Print Network [OSTI]

CLOUD CONDENSATION NUCLEI IN CUMULUS HUMILIS ­ SELECTED CASE STUDY DURING THE CHAPS CAMPAIGN Xiao and particles can partition to cloud droplets by absorption and condensation as well as activation and impact of Oklahoma City. Measurements of interstitial aerosols and residuals of activated condensation cloud nuclei

76

Hardware support for software controlled fast multiplexing of performance counters  

DOE Patents [OSTI]

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.

Salapura, Valentina; Wisniewski, Robert W.

2013-01-01T23:59:59.000Z

77

Hardware support for software controlled fast multiplexing of performance counters  

DOE Patents [OSTI]

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.

Salapura, Valentina; Wisniewski, Robert W

2013-10-01T23:59:59.000Z

78

Advantages and Limitations of the RICH Technique for Particle Identification  

SciTech Connect (OSTI)

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.

Ratcliff, Blair N.; /SLAC

2011-11-07T23:59:59.000Z

79

Antiproton Absorption in Nuclei  

E-Print Network [OSTI]

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.

Yu. T. Kiselev; E. Ya. Paryev

2006-01-24T23:59:59.000Z

80

Shared address collectives using counter mechanisms  

DOE Patents [OSTI]

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.

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

2014-02-18T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Self-regulating neutron coincidence counter  

DOE Patents [OSTI]

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.

Baron, N.

1980-06-16T23:59:59.000Z

82

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...

83

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...

84

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...

85

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...

86

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...

87

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...

88

Hardware support for software controlled fast reconfiguration of performance counters  

DOE Patents [OSTI]

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.

Salapura, Valentina; Wisniewski, Robert W

2013-09-24T23:59:59.000Z

89

Hardware support for software controlled fast reconfiguration of performance counters  

DOE Patents [OSTI]

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.

Salapura, Valentina; Wisniewski, Robert W.

2013-06-18T23:59:59.000Z

90

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

SciTech Connect (OSTI)

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.

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

91

Thermodynamics of pairing transition in hot nuclei  

E-Print Network [OSTI]

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.

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

2014-12-16T23:59:59.000Z

92

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

SciTech Connect (OSTI)

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%.

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

93

Relativistic Hartree-Fock-Bogoliubov model for deformed nuclei  

SciTech Connect (OSTI)

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.

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

94

IBA in deformed nuclei  

SciTech Connect (OSTI)

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.

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

1982-01-01T23:59:59.000Z

95

K- absorption in nuclei by two and three nucleons  

E-Print Network [OSTI]

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.

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

2009-01-08T23:59:59.000Z

96

Gluon density in nuclei  

SciTech Connect (OSTI)

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.

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

97

Superconducting magnet for nuclei orientation  

E-Print Network [OSTI]

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...

Wang, Fa-Chung

1968-01-01T23:59:59.000Z

98

Generalized parton distributions in nuclei  

SciTech Connect (OSTI)

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.

Vadim Guzey

2009-12-01T23:59:59.000Z

99

Counter-Rotating Tandem Motor Drilling System  

SciTech Connect (OSTI)

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.

Kent Perry

2009-04-30T23:59:59.000Z

100

Design, construction and implementation of spherical tissue equivalent proportional counter  

E-Print Network [OSTI]

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...

Perez Nunez, Delia Josefina

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Aerodynamic performance measurements in a counter-rotating aspirated compressor  

E-Print Network [OSTI]

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 ...

Onnée, Jean-François

2005-01-01T23:59:59.000Z

102

Mechanical counter-pressure space suit design using active materials  

E-Print Network [OSTI]

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 ...

Holschuh, Bradley Thomas

2014-01-01T23:59:59.000Z

103

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...

104

Using DMA for copying performance counter data to memory  

DOE Patents [OSTI]

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.

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

2013-12-31T23:59:59.000Z

105

Introduction to Neutron Coincidence Counter Design Based on Boron-10  

SciTech Connect (OSTI)

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.

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

2012-01-22T23:59:59.000Z

106

Message passing with a limited number of DMA byte counters  

DOE Patents [OSTI]

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.

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

107

Electromagnetic reactions on light nuclei  

E-Print Network [OSTI]

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.

Sonia Bacca; Saori Pastore

2014-07-13T23:59:59.000Z

108

Polarized EMC Effect in Nuclei  

SciTech Connect (OSTI)

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.

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

2006-06-05T23:59:59.000Z

109

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

E-Print Network [OSTI]

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.

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

110

Biogenic Potassium Salt Particles as Seeds for Secondary Organic  

E-Print Network [OSTI]

for the condensation of low- or semi-volatile organic compounds from the atmospheric gas phase or multiphase oxidation is most relevant to the activation of cloud condensation nuclei (6). The aerosol samples were collected The fine particles serving as cloud condensation nuclei in pristine Amazonian rainforest air consist mostly

111

Transitional nuclei near shell closures  

SciTech Connect (OSTI)

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.

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

112

Generalized parton distributions of nuclei  

SciTech Connect (OSTI)

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.

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

2009-12-17T23:59:59.000Z

113

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...

114

A scintillation counter for nuclear research  

E-Print Network [OSTI]

particles were counted (the source 26, holder and electrostat1c shield on the tube would certainly stop the alphas; the electrostatic sh1eld, alum~mum of 4 mg. fcm. thick, is capable of stopp1ng alphas up to 4 mev. j, it is possible that some... CD alum1. num. ~ tered slth 2 22 gs/ 5) 4$ PHS &fas (Volts) 4) t 35 . 1'~ 12. , tuteiral 0urves for Etadium O (tufmtered Radium Filtered eith 2 Aluminum. ~ L HgdiUR . 22 mg/em2 5o 4[ PHS Bia/ i Differeutiel. ~ 40 (Volte) peg...

Trail, Carroll Clark

1951-01-01T23:59:59.000Z

115

Nuclear Alpha-Particle Condensates  

E-Print Network [OSTI]

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.

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

2011-03-21T23:59:59.000Z

116

Experimental level-structure determination in odd-odd actinide nuclei  

SciTech Connect (OSTI)

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.

Hoff, R.W.

1985-04-04T23:59:59.000Z

117

Development of large flow-type proportional counters  

E-Print Network [OSTI]

at Texas A&M University involve measurements of the momentum spectra of energetic muons of very low in- tensities. Coincidence telescopes composed of Geiger counters h ve been used as primary detectors to trigger the application of high-voltage pulses... to spark chambers for the purpose of determining the muon traJectories through solid-iron magnetic spectrometers. Geiger counters ha~a b cn chosen for this purpose be ause of the relative ease with which large active areas can bc assembled...

Torline, Norbert Kevin

1967-01-01T23:59:59.000Z

118

Masses and decay properties of nuclei far from stability  

SciTech Connect (OSTI)

A macroscopic-microscopic calculation has been applied to a study of the stability of elements in the heavy and superheavy regions. A folded-Yukawa single-particle potential and a Finite-Range microscopic model were used. Calculated neutron single-particle levels are shown for the spherical nucleus of Z = 114 and A = 298. These are compared to results from an earlier version of the folded-Yukawa potential and to the results of a Woods-Saxon model. Calculated ground-state shell corrections are shown. A small local minimum is seen around Z = 110 and N = 162, which is thought to have a 40 ms half-life. The microscopic correction was calculated for single-particle wells appropriate to 15 nuclei on the line of beta stability. Results obtained with the identical microscopic corrections with the Finite-Range Droplet model for the macroscopic energy are also shown. 12 refs., 4 figs. (LEW)

Moeller, P.; Nix, J.R.; Myers, W.D.; Swiatecki, W.J.

1986-01-01T23:59:59.000Z

119

Heavy Cosmic Ray Nuclei from Extragalactic Sources above 'The Ankle'  

E-Print Network [OSTI]

A very recent observation by the Auger Observatory group claims strong evidence for cosmic rays above 56 EeV being protons from Active Galactic Nuclei. If, as would be expected, the particles above the ankle at about 2 EeV are almost all of extragalactic origin then it follows that the characteristics of the nuclear interactions of such particles would need to be very different from conventional expectation -- a result that follows from the measured positions of 'shower maximum' in the Auger' work. Our own analysis gives a different result, viz that the detected particles are still 'massive' specifically with a mean value of = 2.2 +- 0.8. The need for a dramatic change in the nuclear physics disappears.

Tadeusz Wibig; Arnold W. Wolfendale

2007-12-20T23:59:59.000Z

120

Heavy Cosmic Ray Nuclei from Extragalactic Sources above 'The Ankle'  

E-Print Network [OSTI]

A very recent observation by the Auger Observatory group claims strong evidence for cosmic rays above 56 EeV being protons from Active Galactic Nuclei. If, as would be expected, the particles above the ankle at about 2 EeV are almost all of extragalactic origin then it follows that the characteristics of the nuclear interactions of such particles would need to be very different from conventional expectation -- a result that follows from the measured positions of 'shower maximum' in the Auger' work. Our own analysis gives a different result, viz that the detected particles are still 'massive' specifically with a mean value of = 2.2 +- 0.8. The need for a dramatic change in the nuclear physics disappears.

Wibig, Tadeusz

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Structure functions for light nuclei  

SciTech Connect (OSTI)

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.

S.A. Kulagin, R. Petti

2010-11-01T23:59:59.000Z

122

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

123

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

124

Production-Run Software Failure Diagnosis via Hardware Performance Counters  

E-Print Network [OSTI]

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

Sheridan, Jennifer

125

Optimal Self-Assembly of Counters at Temperature Two  

E-Print Network [OSTI]

Optimal Self-Assembly of Counters at Temperature Two Qi Cheng University of Oklahoma Ashish Goel time of irreversible self-assemblies. 1 Introduction Self-assembly is the ubiquitous process by which been suggested that self-assembly will ultimately become an important technology, enabling

Goel, Ashish

126

Material Surface Design to Counter Electromagnetic Interrogation of Targets  

E-Print Network [OSTI]

Material Surface Design to Counter Electromagnetic Interrogation of Targets H.T. Banks, K. Ito, G and ferromagnetic layers coat- ing a conducting object to provide an attenuation capability against electro. Fresnel's law for the reflectance index is extended to the electromagnetic propagation in anisotropic

127

Confronting Nuclear Risks: Counter-Expertise as Politics Within  

E-Print Network [OSTI]

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 in relation to nuclear energy (Beck 1994: 63­ 76) or a general analysis of the link between nuclear

Gutkin, Boris

128

Counter-rotating Kerr manifolds separated by a fluid shell  

E-Print Network [OSTI]

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.

J. P. Krisch; E. N. Glass

2009-08-13T23:59:59.000Z

129

BABYSCAN - a whole body counter for small children in Fukushima  

E-Print Network [OSTI]

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.

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

2014-01-01T23:59:59.000Z

130

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

E-Print Network [OSTI]

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

Yu, K.N.

131

High spins in gamma-soft nuclei  

SciTech Connect (OSTI)

Nuclei which are soft with respect to the ..gamma.. shape degree of freedom are expected to have many different structures coexisting in the near-yrast regime. In particular, the lowest rotational quasi-particle in a high-j shell exerts a strong polarizing effect on ..gamma... The ..gamma.. to which it drives is found to vary smoothly over a 180/sup 0/ range as the position of the Fermi level varies. This simple rule is seen to have a direct connection with the energy staggering of alternate spin states in rotational bands. A diagram is presented which provides a general theoretical reference for experimental tests of the relation between ..gamma.., spin staggering, configuration, and nucleon number. In a quasicontinuum spectrum, the coexistence of different structures are expected to make several unrelated features appear within any one slice of sum energy and multiplicity. However, it is also seen that the in-band moment of inertia may be similar for many bands of different ..gamma...

Leander, G.A.; Frauendorf, S.; May, F.R.

1982-01-01T23:59:59.000Z

132

Dual Origin of Pairing in Nuclei  

E-Print Network [OSTI]

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.

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

2014-04-29T23:59:59.000Z

133

Structure functions for light nuclei  

SciTech Connect (OSTI)

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.

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

134

Pair production in counter-propagating laser beams  

E-Print Network [OSTI]

Based on an analysis of a specific electron trajectory in counter-propagating beams, Bell & Kirk (PRL 101, 200403 (2008)) recently suggested that laboratory lasers may shortly be able to produce significant numbers of electron-positron pairs. We confirm their results using an improved treatment of nonlinear Compton scattering in the laser beams. Implementing an algorithm that integrates classical electron trajectories, we then examine a wide range of laser pulse shapes and polarizations. We find that counter-propagating, linearly polarized beams, with either aligned or crossed orientation, are likely to initiate a pair avalanche at intensities of approximately 10^{24} Watts/sq cm per beam. The same result is found by modelling one of the beams as a wave reflected at the surface of an overdense solid.

J. G. Kirk; A. R. Bell; I. Arka

2009-06-24T23:59:59.000Z

135

Visible light photon counters optimization for quantum information applications  

SciTech Connect (OSTI)

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.

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

136

On spectroscopic factors of magic and semimagic nuclei  

SciTech Connect (OSTI)

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.

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

137

Nuclei embedded in an electron gas  

E-Print Network [OSTI]

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.

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

2007-06-11T23:59:59.000Z

138

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

E-Print Network [OSTI]

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.

Horst Mueller; Byron K. Jennings

1998-07-09T23:59:59.000Z

139

Particle Astrophysics  

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

Particle Astrophysics Particle Astrophysics Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten...

140

''Bare'' single-particle energies in Ni-56  

E-Print Network [OSTI]

The structure of the low-lying levels in the mirror nuclei Ni-57 and Cu-57 is described within the extended unified model. The problem of single-particle energies in Ni-56 is treated in detail. ''Bare'' single-particle energies are extracted from...

Trache, L.; Kolomiets, A.; Shlomo, S.; Heyde, K.; Dejbakhsh, H.; Gagliardi, Carl A.; Tribble, Robert E.; Zhou, XG; Jacob, VE; Oros, AM.

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Nuclear structure studies of medium-mass nuclei using large Ge arrays  

SciTech Connect (OSTI)

The advent of large Ge arrays and their ancillary detectors has greatly advanced spectroscopic studies of the medium-mass nuclei. These nuclei undergo rapid shape changes as a function of spin, excitation energy and particle number and, thus, provide a unique laboratory to test and refine a variety of theoretical models. Following a brief review of the physics motivation, some of the highlights of the experimental results obtained with the help of these powerful detector systems will be discussed. Among results presented here are the newly-discovered island of superdeformation in the A{approximately}80 mass region, and the high-spin band structures in the N{approximately}Z nuclei. These band structures may be understood in the framework of the conventional cranking models, without the introduction of additional T=0 neutron-proton pairing correlations.

Baktash, C.

1996-12-31T23:59:59.000Z

142

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

E-Print Network [OSTI]

of positive ella=. . sc surround-ng the anode. Tire sheath. o char ge begins its c=. f. G. 'w=. zc. w +h 'az = cce c at on because o ti:e stzoz ? e ectric mGtlG G 1, . C lc. rc Co 11 u C S C rc "'"y f GI 1 t' e C1CC' 1C icic . :-. ;;. -. 'o . . --. ' . ilc...

Bull, Kenneth Winson

1965-01-01T23:59:59.000Z

143

Ab initio Bogoliubov coupled cluster theory for open-shell nuclei  

E-Print Network [OSTI]

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.

Angelo Signoracci; Thomas Duguet; Gaute Hagen; Gustav Jansen

2014-12-08T23:59:59.000Z

144

Fabrication of solar cells with counter doping prevention  

DOE Patents [OSTI]

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.

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

2013-02-19T23:59:59.000Z

145

Measurement of photon correlations with multipixel photon counters  

E-Print Network [OSTI]

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.

Dmitry Kalashnikov; Leonid A. Krivitsky

2014-08-01T23:59:59.000Z

146

Particle acceleration in relativistic subluminal shock environments  

E-Print Network [OSTI]

The understanding of the particle spectra resulting from acceleration in relativistic shocks as they occur in extragalactic sources, is essential for the interpretation of the cosmic ray spectrum above the ankle ($E_p>3\\cdot 10^{18}$ eV). It is believed that extragalactic sources like Active Galactic Nuclei and Gamma Ray Bursts can produce particle spectra up to $E_p\\sim 10^{21}$ eV. In this contribution, subluminal shocks are investigated with respect to different shock boost factors $\\Gamma$ and the inclination angle between the shock normal and the magnetic field $\\psi$. A correlation between the boost factor and the spectral behavior of the emitted particles is found. The results are compared to Active Galactic Nuclei and Gamma Ray Burst diffuse cosmic ray contribution and the observed cosmic ray spectrum at the highest energies.

A. Meli; J. Becker; J. J. Quenby; J. Luenemann

2007-08-10T23:59:59.000Z

147

Particle separation  

DOE Patents [OSTI]

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.

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

2011-04-26T23:59:59.000Z

148

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

SciTech Connect (OSTI)

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.

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

149

Hidden pseudospin and spin symmetries and their origins in atomic nuclei  

E-Print Network [OSTI]

Symmetry plays a fundamental role in physics. The quasi-degeneracy between single-particle orbitals $(n, l, j = l + 1/2)$ and $(n-1, l + 2, j = l + 3/2)$ indicates a hidden symmetry in atomic nuclei, the so-called pseudospin symmetry (PSS). Since the introduction of the concept of PSS in atomic nuclei, there have been comprehensive efforts to understand its origin. Both splittings of spin doublets and pseudospin doublets play critical roles in the evolution of magic numbers in exotic nuclei discovered by modern spectroscopic studies with radioactive ion beam facilities. Since the PSS was recognized as a relativistic symmetry in 1990s, many special features, including the spin symmetry (SS) for anti-nucleon, and many new concepts have been introduced. In the present Review, we focus on the recent progress on the PSS and SS in various systems and potentials, including extensions of the PSS study from stable to exotic nuclei, from non-confining to confining potentials, from local to non-local potentials, from central to tensor potentials, from bound to resonant states, from nucleon to anti-nucleon spectra, from nucleon to hyperon spectra, and from spherical to deformed nuclei. Open issues in this field are also discussed in detail, including the perturbative nature, the supersymmetric representation with similarity renormalization group, and the puzzle of intruder states.

Haozhao Liang; Jie Meng; Shan-Gui Zhou

2014-11-25T23:59:59.000Z

150

Cloud Condensation Nuclei Retrievals at Cloud Base in North Dakota  

E-Print Network [OSTI]

Cloud Condensation Nuclei Retrievals at Cloud Base in North Dakota · Mariusz Starzec #12;Motivation Compare University of Wyoming (UWyo) and Droplet Measurement Technologies (DMT) cloud condensation nuclei condensation nuclei concentration (CCNC) at any supersaturation (SS) #12;Background Aerosols act as nuclei

Delene, David J.

151

Nuclear structure and reactions with stored nuclei  

SciTech Connect (OSTI)

The use of ion-storage rings is discussed for studies of nuclear reactions and structure, with emphasis on energetic beams of short- lived, radioactive nuclei. Aspects of internal versus external luminosity are considered as well as other issues connected with the inverse kinematics of reactions induced by a circulating beam of complex nuclei. Some of the physics motivation that is driving studies with radioactive beams is described.

Henning, W.

1996-12-31T23:59:59.000Z

152

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]

(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

Ahmad, Sajjad

153

The Fractal Geometrical Properties of Nuclei  

E-Print Network [OSTI]

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.

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

154

Coincidence counter design for the assay of vitrified nuclear waste  

SciTech Connect (OSTI)

For the termination of nuclear safeguards and transfers to waste storage, the verification of the plutonium content in vitrified nuclear waste is required by international safeguards agreements. A novel design has been used to develop a coincidence counter for measuring vitrified nuclear waste. The authors have devised a method to measure the {sup 244}Cm content and to calculate the plutonium content from the curium-to-plutonium ratio. In order to provide unattended inspection, the counter is designed for continuous operation in the presence of highly radioactive samples: 3.0 {times} 10{sup 7} Rad/h gamma and 9.0 {times} 10{sup 7}/s neutron fluence. Operability under these conditions has been obtained by designing a heavily shielded detector with radiation hard components subtending a limited solid angle. A counting technique, Localized Source Term Coincidence Counting, has been developed to allow neutron assay of this type of sample. The system will be installed at the Power Nuclear Corporation Tokai Vitrification Facility in the later part of 1998.

Beddingfield, D.H.; Menlove, H.O. [Los Alamos National Lab., NM (United States); Iwamoto, T.; Tomikawa, H. [Power Nuclear Corp. (Japan)

1998-12-31T23:59:59.000Z

155

Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC  

SciTech Connect (OSTI)

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.

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

2010-11-01T23:59:59.000Z

156

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

E-Print Network [OSTI]

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...

Mallett, Michael Wesley

1990-01-01T23:59:59.000Z

157

Photon-Veto Counters at the Outer Edge of the Endcap Calorimeter for the KOTO Experiment  

E-Print Network [OSTI]

The Outer-Edge Veto (OEV) counter subsystem for extra-photon detection from the backgrounds to the? $K^0_L\\rightarrow\\pi^0\

T. Matsumura; T. Shinkawa; H. Yokota; E. Iwai; T. K. Komatsubara; J. W. Lee; G. Y. Lim; J. Ma; T. Masuda; H. Nanjo; T. Nomura; Y. Odani; Y. D. Ri; K. Shiomi; Y. Sugiyama; S. Suzuki; M. Togawa; Y. Wah; H. Watanabe; T. Yamanaka

2014-12-26T23:59:59.000Z

158

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

SciTech Connect (OSTI)

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

Center for Human Reliability Studies

2008-02-01T23:59:59.000Z

159

{alpha}-decay spectroscopy of deformed nuclei reexamined  

SciTech Connect (OSTI)

We perform an extensive analysis of {alpha}-decays to 2{sup +} and 4{sup +} states in deformed even-even nuclei by using the stationary coupled channels approach. Collective excitations are described within the rigid rotor model. The {alpha}-nucleus interaction is given by a double folding procedure with M3Y plus Coulomb nucleon-nucleon forces. We use a repulsive potential with one independent parameter in order to localize the {alpha}-particle on the nuclear surface and to fit the experimental Q-value. The decaying state is identified with the first resonance inside the resulting pocket-like potential, as suggested by microscopic calculations. We obtain a good agreement with existing experimental data concerning decay widths to J=2{sup +},4{sup +} states. The total {alpha}-decay half-lives agrees very well with experimental values by fitting the spectroscopic factor in terms of charge and neutron numbers separately for Z<82 and Z>82. We give predictions for intensities and hindrance factors for 52 even-even {alpha}-emitters with {beta}{sub 2}>0.15 and E{sub 2{sup +}}<200 kev. Comparison between the phenomenological and microscopic spectroscopic factors revealed large {alpha}-clustering components for nuclei close and above N=82,Z=82,N=126 magic numbers.

Peltonen, S.; Suhonen, J. [Department of Physics, University of Jyvaeskylae, POB 35, FIN-40351, Jyvaeskylae (Finland); Delion, D. S. [National Institute of Physics and Nuclear Engineering, Atomistilor 407, Bucharest-Magurele, 077125 (Romania); Academy of Romanian Scientists, 54 Splaiul Independentei, Bucharest, 050085 (Romania)

2008-09-15T23:59:59.000Z

160

Light nuclei quasiparticle energy shift in hot and dense nuclear matter  

E-Print Network [OSTI]

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 $\

G. Röpke

2008-10-25T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Tidal waves as yrast states in transitional nuclei  

E-Print Network [OSTI]

The yrast states of transitional nuclei are described as quadrupole waves running over the nuclear surface, which we call tidal waves. In contrast to a rotor, which generates angular momentum by increasing the angular velocity at approximately constant deformation, a tidal wave generates angular momentum by increasing the deformation at approximately constant angular velocity. The properties of the tidal waves are calculated by means of the cranking model in a microscopic way. The calculated energies and E2 transition probabilities of the yrast states in the transitional nuclides with $Z$= 44, 46, 48 and $N=56, 58, ..., 66$ reproduce the experiment in detail. The nonlinear response of the nucleonic orbitals results in a strong coupling between shape and single particle degrees of freedom.

S. Frauendorf; Y. Gu; J. Sun

2010-02-16T23:59:59.000Z

162

Active Galactic Nuclei under the scrutiny of CTA  

E-Print Network [OSTI]

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...

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

163

FB-line neutron multiplicity counter operation manual  

SciTech Connect (OSTI)

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.

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

1997-12-31T23:59:59.000Z

164

Underground Muon Counters as a Tool for Composition Analyses  

E-Print Network [OSTI]

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.

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

2008-10-13T23:59:59.000Z

165

Entrance channel dependence in compound nuclear reactions with loosely bound nuclei  

E-Print Network [OSTI]

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.

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

2005-05-13T23:59:59.000Z

166

Single-ended counter-rotating radial turbine for space application  

DOE Patents [OSTI]

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.

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

1987-05-13T23:59:59.000Z

167

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

E-Print Network [OSTI]

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

Brown, Michael R.

168

Functionalized Graphene as a Catalytic Counter Electrode in Dye-Sensitized  

E-Print Network [OSTI]

Functionalized Graphene as a Catalytic Counter Electrode in Dye-Sensitized Solar Cells Joseph D.1021/nn1016428 © 2010 American Chemical Society ABSTRACT When applied on the counter electrode of a dye-sensitized and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States D ye-sensitized

Aksay, Ilhan A.

169

Microwave Photon Counter Based on Josephson Junctions Y.-F. Chen,1,* D. Hover,1  

E-Print Network [OSTI]

Microwave Photon Counter Based on Josephson Junctions Y.-F. Chen,1,* D. Hover,1 S. Sendelbach,1 L on the current-biased Josephson junction. The junction is tuned to absorb single microwave photons from optical photon counters, it is natural to consider the Josephson junction--a nonlinear, nondissipative

Saffman, Mark

170

Is Fusion Inhibited for Weakly Bound Nuclei?  

SciTech Connect (OSTI)

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}

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

171

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)

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.

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

172

Polarized structure functions of nucleons and nuclei  

SciTech Connect (OSTI)

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.

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

2007-09-16T23:59:59.000Z

173

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

SciTech Connect (OSTI)

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.

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

174

New limit on the mass of 9.4-keV solar axions emitted in an M1 transition in $^{83}$Kr nuclei  

E-Print Network [OSTI]

A search for resonant absorption of the solar axion by $^{83}\\rm{Kr}$ nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the combination of isoscalar and isovector axion-nucleon couplings $|g_3-g_0|\\leq 1.69\\times 10^{-6}$ allowed us to set the new upper limit on the hadronic axion mass of $m_{A}\\leq 130$ eV (95\\% C.L.) with the generally accepted values $S$=0.5 and $z$=0.56.

Derbin, A V; Gavrilyuk, Yu M; Kazalov, V V; Kim, H J; Kim, Y D; Kobychev, V V; Kuzminov, V V; Ali, Luqman; Muratova, V N; Panasenko, S I; Ratkevich, S S; Semenov, D A; Tekueva, D A; Yakimenko, S P; Unzhakov, E V

2015-01-01T23:59:59.000Z

175

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

SciTech Connect (OSTI)

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.

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

176

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...

177

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

SciTech Connect (OSTI)

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.

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

178

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

E-Print Network [OSTI]

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.

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

2008-08-07T23:59:59.000Z

179

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

E-Print Network [OSTI]

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.

R. Budaca; A. A. Raduta

2013-01-25T23:59:59.000Z

180

Transfer-induced fission of superheavy nuclei  

SciTech Connect (OSTI)

Possibilities of transfer-induced fission of new isotopes of superheavy nuclei with charge numbers 103-108 are studied for the first time in the reactions {sup 48}Ca+{sup 244,246,248}Cm at energies near the corresponding Coulomb barriers. The predicted cross sections are found to be measurable with the detection of three-body final states.

Adamian, G. G. [Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Institute of Nuclear Physics, Tashkent, UZ-702132 Uzbekistan (Uzbekistan); Antonenko, N. V.; Zubov, A. S. [Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Sargsyan, V. V. [Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Yerevan State University, Yerevan (Armenia); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)

2010-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Thermodynamics of nuclei in thermal contact  

E-Print Network [OSTI]

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.

Karl-Heinz Schmidt; Beatriz Jurado

2010-10-05T23:59:59.000Z

182

Four-body correlations in nuclei  

E-Print Network [OSTI]

Low-energy spectra of 4$n$ nuclei are described with high accuracy in terms of four-body correlated structures ("quartets"). The states of all $N\\geq Z$ nuclei belonging to the $A=24$ isobaric chain are represented as a superposition of two-quartet states, with quartets being characterized by isospin $T$ and angular momentum $J$. These quartets are assumed to be those describing the lowest states in $^{20}$Ne ($T_z$=0), $^{20}$F ($T_z$=1) and $^{20}$O ($T_z$=2). We find that the spectrum of the self-conjugate nucleus $^{24}$Mg can be well reproduced in terms of $T$=0 quartets only and that, among these, the $J$=0 quartet plays by far the leading role in the structure of the ground state. The same conclusion is drawn in the case of the three-quartet $N=Z$ nucleus $^{28}$Si. As an application of the quartet formalism to nuclei not confined to the $sd$ shell, we provide a description of the low-lying spectrum of the proton-rich $^{92}$Pd. The results achieved indicate that, in 4$n$ nuclei, four-body degrees of f...

Sambataro, M

2015-01-01T23:59:59.000Z

183

Photon parton distributions in nuclei and the EMC effect  

SciTech Connect (OSTI)

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.

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

184

Photon parton distributions in nuclei and the EMC effect  

SciTech Connect (OSTI)

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.

Leonid Frankfurt, Mark Strikman

2010-12-01T23:59:59.000Z

185

Photon parton distributions in nuclei and the EMC effect  

E-Print Network [OSTI]

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.

Leonid Frankfurt; Mark Strikman

2010-12-15T23:59:59.000Z

186

Nuclear Counter Effect of Silicon PIN Photodiode used in  

E-Print Network [OSTI]

We investigated the nuclear counter effect of the silicon PIN photodiode mounted on a CsI(T`) crystal array as a result of the leakage of electromagnetic shower through the rear end of the crystal. Using 1 GeV and 2 GeV electron beams at KEK, we estimated its effect on the energy measurement by the CsI(T`) calorimeter of BELLE experiment. The results are found to be in good agreement with that of GEANT simulation and the expected effect for the BELLE calorimeter is negligible. 1 Introduction A high resolution electromagnetic calorimeter made by inorganic crystal scintillators with silicon PIN photodiode read out has been popular in recent high energy physics experiments [1]. In the BELLE experiment [2] at KEK B factory, we plan to use 8736 pieces of CsI(T`) crystals [3] each with two silicon PIN photodiodes [4]. The photodiode has 2 cm 2 sensitive area and is glued on the rear face of 30 cm long crystal. It has been pointed out that some of the electrons and photons in an electrom...

Csi Calorimeter; Belle Preprint; A. Satpathy; K. Tamai; M. Fukushima; D. Y. Kim; M. H. Lee

187

Real-time multi-mode neutron multiplicity counter  

DOE Patents [OSTI]

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.

Rowland, Mark S; Alvarez, Raymond A

2013-02-26T23:59:59.000Z

188

Counter flow cooling drier with integrated heat recovery  

DOE Patents [OSTI]

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.

Shivvers, Steve D. (Prole, IA)

2009-08-18T23:59:59.000Z

189

A Counter-IED Preparedness Methodology for Large Event Planning  

SciTech Connect (OSTI)

Since 2009, Oak Ridge National Laboratory (ORNL) has been involved in a project sponsored by the Department of Homeland Security Science and Technology Directorate aimed at improving preparedness against Improvised Explosive Devices (IED) at large sporting events. Led by the University of Southern Mississippi (USM) as part of the Southeast Region Research Initiative, the project partners have been developing tools and methodologies for use by security personnel and first responders at sports stadiums. ORNL s contribution has been to develop an automated process to gather and organize disparate data that is usually part of an organization s security plan. The organized data informs a table-top exercise (TTX) conducted by USM using additional tools developed by them and their subcontractors. After participating in several pilot TTXs, patterns are beginning to emerge that would enable improvements to be formulated to increase the level of counter-IED preparedness. This paper focuses on the data collection and analysis process and shares insights gained to date.

Payne, Patricia W [ORNL; Koch, Daniel B [ORNL

2011-01-01T23:59:59.000Z

190

Improved Technology To Prevent Nuclear Proliferation And Counter Nuclear Terrorism  

SciTech Connect (OSTI)

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.

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

2006-06-12T23:59:59.000Z

191

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

E-Print Network [OSTI]

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.

Vanhalst, Maarten; Cosyn, Wim

2012-01-01T23:59:59.000Z

192

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

E-Print Network [OSTI]

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.

Maarten Vanhalst; Jan Ryckebusch; Wim Cosyn

2012-10-23T23:59:59.000Z

193

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

E-Print Network [OSTI]

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...

Chaudhuri, G

2004-01-01T23:59:59.000Z

194

REVIEW OF PARTICLE PHYSICS  

E-Print Network [OSTI]

ONLINE PARTICLE PHYSICS INFORMATION 1.3. Particle Physics Information Platforms . . . . . . . . .14. Particle Physics Education and Outreach

Beringer, Juerg

2013-01-01T23:59:59.000Z

195

Review of Particle Physics  

E-Print Network [OSTI]

11. Particle Physics Education Sites . . . . . . . . .ONLINE PARTICLE PHYSICS INFORMATION 1.11. Particle Physics Education Sites . . . . . . . . . . 12.

Nakamura, Kenzo

2010-01-01T23:59:59.000Z

196

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

E-Print Network [OSTI]

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...

Lawrence, Nicholas M.

2010-10-12T23:59:59.000Z

197

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

SciTech Connect (OSTI)

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.

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

198

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

E-Print Network [OSTI]

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 ...

Buechley, Leah

199

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

E-Print Network [OSTI]

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. ...

Parker, David V. (David Vickery)

2005-01-01T23:59:59.000Z

200

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

E-Print Network [OSTI]

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 ...

Wee, Brian (Brian J.)

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

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

E-Print Network [OSTI]

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.

Gargi Chaudhuri

2004-11-01T23:59:59.000Z

202

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

E-Print Network [OSTI]

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.

Ikuko Hamamoto

2012-06-18T23:59:59.000Z

203

Silicate absorption in heavily obscured galaxy nuclei  

E-Print Network [OSTI]

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.

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

2006-10-19T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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.

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

2014-11-01T23:59:59.000Z

205

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

E-Print Network [OSTI]

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...

Gaston, Gary W

1976-01-01T23:59:59.000Z

206

Proposal for the aerogel Cherenkov counters for the PEP-N detector  

E-Print Network [OSTI]

The work is devoted to the development of the aerogel Cherenkov counters with the light collection on wavelength shifters and PMTs (ASHIPH). The ASHIPH system has been developed for the KEDR detector. Tests of the counters have been carried out on the Dubna accelerator, the pi/K separation obtained is about 4 sigma. The ASHIPH system is suggested for the PEP-N detector.

M. Yu. Barnyakov; V. S. Bobrovnikov; A. R. Buzykaev; G. M. Kolachev; S. A. Kononov; E. A. Kravchenko; G. D. Minakov; A. P. Onuchin; A. F. Danilyuk; F. F. Guber; A. B. Kurepin; V. A. Krasnov

2001-06-05T23:59:59.000Z

207

Deeply virtual Compton scattering off nuclei  

SciTech Connect (OSTI)

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.

Voutier, Eric

2009-01-01T23:59:59.000Z

208

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

SciTech Connect (OSTI)

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.

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

209

Electromagnetic Dipole Strength in Transitional Nuclei  

E-Print Network [OSTI]

Electromagnetic dipole absorption cross-sections of transitional nuclei with large-amplitude shape fluctuations are calculated in a microscopic way by introducing the concept of Instantaneous Shape Sampling. The concept bases on the slow shape dynamics as compared to the fast dipole vibrations. The elctromagnetic dipole strength is calculated by means of RPA for the instantaneous shapes, the probability of which is obtained by means of IBA. Very good agreement with the experimental absorption cross sections near the nucleon emission threshold is obtained.

S. Q. Zhang; I. Bentley; S. Brant; F. Dönau; S. Frauendorf; B. Kämpfer; R. Schwengner; A. Wagner

2008-08-19T23:59:59.000Z

210

Quantum Monte Carlo calculations for light nuclei  

SciTech Connect (OSTI)

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.

Wiringa, R.B.

1998-08-01T23:59:59.000Z

211

Local Fermi gas in inclusive muon capture from nuclei  

E-Print Network [OSTI]

We compare local Fermi gas and shell model in muon capture in nuclei in order to estimate the effect of finite nuclear size in low energy weak reactions.

J. E. Amaro; J. Nieves; M. Valverde; C. Maieron

2006-05-20T23:59:59.000Z

212

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

E-Print Network [OSTI]

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.

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

2014-08-11T23:59:59.000Z

213

Empirical investigation of extreme single-particle behavior of nuclear quadrupole moments in highly collective A similar to 150 superdeformed bands  

E-Print Network [OSTI]

The intrinsic quadrupole moment Q(0) of superdeformed rotational bands in A similar to 150 nuclei depends on the associated single-particle configuration. We have derived an empirical formula based on the additivity of ...

Clark, S. T.; Hackman, G.; Floor, S. N.; Norris, J.; Sanders, Stephen J.

2001-10-01T23:59:59.000Z

214

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

SciTech Connect (OSTI)

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.

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

215

Proton-neutron pairing vibrations in N=Z nuclei: Precursory soft mode of isoscalar pairing condensation  

E-Print Network [OSTI]

L=0 proton-neutron ($pn$) pair-addition and pair-removal strengths in $^{40}$Ca and $^{56}$Ni are investigated by means of the $pn$ particle-particle random-phase approximation employing a Skyrme energy-density functional. It is found that the collectivity of the lowest $J^\\pi = 1^+$ state in the adjacent odd-odd nuclei becomes stronger as the strength of the isoscalar (T=0) pairing interaction increases. The results suggest the emergence of the T=0 $pn$-pairing vibrational mode as a possible critical phenomenon toward the T=0 pairing condensation.

Kenichi Yoshida

2014-09-17T23:59:59.000Z

216

Search for long lived heaviest nuclei beyond the valley of stability  

E-Print Network [OSTI]

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.

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

2008-02-26T23:59:59.000Z

217

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

E-Print Network [OSTI]

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....

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

2015-01-21T23:59:59.000Z

218

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

E-Print Network [OSTI]

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

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

219

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

DOE Patents [OSTI]

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.

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

2013-09-03T23:59:59.000Z

220

Particle Astrophysics  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 TheSteven Ashby Dr.presentationsParticipant ObligationsParticle

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Statistics of particle time-temperature histories.  

SciTech Connect (OSTI)

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.

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

2014-10-01T23:59:59.000Z

222

Conducting polymers based counter electrodes for dye-sensitized solar cells  

SciTech Connect (OSTI)

Conducting polymer films were synthesized and employed as an alternative to expensive platinum counter electrodes for dye-sensitized solar cells. poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin films were spin-coated and polypyrrole films were electrochemically deposited via cyclic voltammetry method on ITO substrates. The morphology of the films were imaged by SEM and AFM. These films show good catalytic activity towards triiodide reduction as compared to Pt/FTO electrodes. Finally the photovoltaic performance of DSSC fabricated using N3 dye were compared with PT/FTO, PEDOT/ITO, and e-PPy counter electrodes.

Veerender, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Saxena, Vibha, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gusain, Abhay, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Jha, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Koiry, S. P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Chauhan, A. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Aswal, D. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gupta, S. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India)

2014-04-24T23:59:59.000Z

223

Esplorazione Della Terra Incognita Della Fisica Nucleare: Nuclei Con Alone, Nuclei "A Grappoli", Nuclei Borromeani e Altre Stranezze Esotiche!  

E-Print Network [OSTI]

English: If the current status of theoretical and experimental knowledge in Nuclear Physics could be reduced to a geographical chart or a planisphere, then our epoch would be in some respect comparable to the end of the Medieval age and in other to the beginning of the Reinassance: epochs in which, together with the consolidated knowledge of the Old World, there have been great and revolutionary expeditions as the discovery of America or the periplus of Cape of Good Hope, explorations aimed at reaching the limits that, along the centuries, have lead to more and more engaging scientific discoveries in more and more far away lands, ending only in the twentieth century with the complete mapping of all the continents. Nuclear Physics is living an analogous adventure on the plane of contrast... - Italian: Se lo stato attuale delle conoscenze teoriche e sperimentali della Fisica Nucleare si potesse ridurre a una carta geografica o un mappamondo, allora la nostra epoca si potrebbe paragonare per certi versi alla fine del Medioevo e per altri al Rinascimento: epoche in cui, accanto alla conoscenza consolidata del Vecchio mondo, ci furono grandi e rivoluzionarie spedizioni come la scoperta dell'America o il periplo del Capo di Buona Speranza, esplorazioni geografiche volte al raggiungimento dei limiti che, nel corso dei secoli, hanno portato a scoperte scientifiche sempre pi\\`u avvincenti in terre sempre pi\\`u lontane, culminate solo nel ventesimo secolo con la completa mappatura di tutte le terre emerse. La Fisica Nucleare sta vivendo un'avventura analoga sul piano della contrapposizione tra la conoscenza acquisita sui nuclei stabili e la scoperta delle sorprendenti propriet\\`a esotiche dei nuclei instabili, pi\\`u difficili da produrre, da studiare e da comprendere.

Lorenzo Fortunato

2011-04-04T23:59:59.000Z

224

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

E-Print Network [OSTI]

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 ...

Filippone, Bradley W.

225

Multiparticle interactions in backward proton production, subthreshold antiproton production, and inclusive electron scattering from nuclei  

SciTech Connect (OSTI)

The phenomena of backward proton emission and subthreshold antiproton production in the proton-nucleus interactions, and findings from the inclusive scattering of electrons from nuclei, are interpreted in terms of multiparticle interactions. Rates for multiparticle collisions are calculated using the results from many-body theory, with the products of the squared interaction amplitudes and Wigner functions. The rates for the processes with different number of particles are proportional to the different powers of spatial density. The many-body amplitudes are expanded in terms of propagators and elementary amplitudes with only two particles in the initial state. The leading processes are isolated on a tree level. They correspond to the expansion of a ground-state nuclear wave function. Reasonable agreement with data is obtained.

Danielewicz, P. (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (USA) Department of Physics Astronomy, Michigan State University, East Lansing, MI (USA))

1990-10-01T23:59:59.000Z

226

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

DOE Patents [OSTI]

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.

Klunder, Edgar B. (Bethel Park, PA)

2011-08-09T23:59:59.000Z

227

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

E-Print Network [OSTI]

Gas Analysis SO2 , NO, NO2 , CO, CO2 , THC, O2Sample Tanks Particle Probe Gas Probe Exhaust DMA - Differential Mobility Analyzer CNC ­ Condensation Nuclei Counter HPLPC ­ High Pressure Large Particle Counter.kostic.niu.edu Statistical Measurement Theory · Sample - a `selected set' of `population' · Measurand - measured variable (x

Kostic, Milivoje M.

228

Subthreshold Photofission of Even-Even Nuclei  

SciTech Connect (OSTI)

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.

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

2005-09-01T23:59:59.000Z

229

Searching for E(5) behavior in nuclei  

SciTech Connect (OSTI)

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.

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

230

Mean field and collisions in hot nuclei  

SciTech Connect (OSTI)

Collisions between heavy nuclei produce nuclear matter of high density and excitation. Brueckner methods are used to calculate the momentum and temperature dependent mean field for nucleons propagating through nuclear matter during these collisions. The mean field is complex and the imaginary part is related to the ''two-body'' collision, while the real part relates to ''one-body'' collisions. A potential model for the N-N interactions is avoided by calculating the Reaction matrix directly from the T-matrix (i.e., N-N phase shifts) using a version of Brueckner theory previously published by the author. Results are presented for nuclear matter at normal and twice normal density and for temperatures up to 50 MeV. 23 refs., 7 figs.

K /umlt o/hler, H.S.

1989-06-01T23:59:59.000Z

231

EMC and polarized EMC effects in Nuclei  

SciTech Connect (OSTI)

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.

Ian Cloet; Wolfgang Bentz; Anthony Thomas

2006-05-23T23:59:59.000Z

232

EMC and Polarized EMC Effects in Nuclei  

E-Print Network [OSTI]

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.

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

2006-05-24T23:59:59.000Z

233

E-Print Network 3.0 - atomic nuclei implication Sample Search...  

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

Summary: The photoresponse of heavy nuclei - some implications on nucleosynthesis Nuclear physics... and the p-process Photoresponse of atomic nuclei Structure of the...

234

E-Print Network 3.0 - atomic nuclei produced Sample Search Results  

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

Summary: . The dependence of obtained values for superheavy nuclei produced in cold fusion reactions on di27;erent... values for superheavy nuclei produced in cold...

235

E-Print Network 3.0 - astatine compound nuclei Sample Search...  

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

HASSIUM, Summary: , the production of weakly excited heavy compound nuclei by complete fusion using lead or bismuth targets... the production of cold compound nuclei with...

236

Search milli-charged particles at SLAC  

SciTech Connect (OSTI)

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}.

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

1997-01-01T23:59:59.000Z

237

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

E-Print Network [OSTI]

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

Zhang, Yong-Tao

238

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

E-Print Network [OSTI]

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

Lee, Hsien-Hsin "Sean"

239

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

E-Print Network [OSTI]

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

Boal, David

240

EXPERIMENTAL INVESTIGATIONS ON THE DESIGN OF A DUCTED COUNTER-ROTATING AXIAL FLOW FANS SYSTEM  

E-Print Network [OSTI]

[] Number of blades FR [] Front rotor R [mm] Blade radius RR [] Rear rotor CRS [] Counter-rotating system W to a conventional rotor or to a rotor-stator stage. The study of the variation of the rotation rates ratio show of the axial distance be- tween rotors does not seem to change the overall per- formances. This system has thus

Boyer, Edmond

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Design of a wall-less proportional counter for microdosimetry in nanometer dimensions  

E-Print Network [OSTI]

, at nanometer dimensions. The main contribution of this research is the design of a cylindrical wall-less proportional counter of 1mm height by 1mm diameter. A wall-less detector (also called grid-walled detector) overcomes the so-called Â?wall effect...

Rayadurgam, Sripriya

2006-08-16T23:59:59.000Z

242

Instrumenting Linear Algebra Energy Consumption via On-chip Energy Counters  

E-Print Network [OSTI]

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

California at Berkeley, University of

243

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

E-Print Network [OSTI]

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

Bertini, Robert L.

244

A Performance Counter Based Workload Characterization on Blue Gene/P  

E-Print Network [OSTI]

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

John, Lizy Kurian

245

On how to calculate methane lifetime from OH concentrations (FORTRAN): Integer I, J, L ! counters  

E-Print Network [OSTI]

On how to calculate methane lifetime from OH concentrations (FORTRAN): Integer I, J, L ! counters_ch4 ! methane lifetime (years) C Initialize: ch4_sum=0. yield=0. C Calculate sums: Do J = 1 , JM Do I in tropospheric ozone and methane; global 3D model studies, Atmospheric Environment, 33, 961-977, 1999

Haak, Hein

246

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

E-Print Network [OSTI]

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

Leue, Stefan

247

Many-Body Interactions of Neutrinos with Nuclei - Observables  

E-Print Network [OSTI]

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.

O. Lalakulich; K. Gallmeister; U. Mosel

2014-09-24T23:59:59.000Z

248

Particle vibrational coupling in covariant density functional theory  

E-Print Network [OSTI]

A consistent combination of covariant density functional theory (CDFT) and Landau-Migdal Theory of Finite Fermi Systems (TFFS) is presented. Both methods are in principle exact, but Landau-Migdal theory cannot describe ground state properties and density functional theory does not take into account the energy dependence of the self-energy and therefore fails to yield proper single-% particle spectra as well as the coupling to complex configurations in the width of giant resonances. Starting from an energy functional, phonons and their vertices are calculated without any further parameters. They form the basis of particle-vibrational coupling leading to an energy dependence of the self-energy and an induced energy-dependent interaction in the response equation. A subtraction procedure avoids double counting. Applications in doubly magic nuclei and in a chain of superfluid nuclei show excellent agreement with experimental data.

P. Ring; E. Litvinova

2010-06-21T23:59:59.000Z

249

Super Heavy Nuclei over Critical Fields and their Conections  

SciTech Connect (OSTI)

Low energy collisions of very heavy nuclei (238U+238U, 232Th+250Cf and 238U+248Cm) have been studied within the realistic dynamical model based on multi-dimensional Langevin equations. Large charge and mass transfer was found due to the 'inverse quasi-fission' process leading to formation of survived superheavy long-lived neutron-rich nuclei. In many events lifetime of the composite system consisting of two touching nuclei turns out to be rather long; sufficient for spontaneous positron formation from super-strong electric field, a fundamental QED process.

Greiner, Walter [Frankfurt Institute for Advanced Studies, J.W. Goethe-Universitaet, 60325 Frankfurt (Germany); Zagrebaev, Valery [Flerov Laboratory of Nuclear Reaction, JINR, Dubna, 141980, Moscow region (Russian Federation)

2007-04-28T23:59:59.000Z

250

New measurements of the EMC effect in light nuclei  

SciTech Connect (OSTI)

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.

A. Daniel

2009-12-01T23:59:59.000Z

251

New measurements of the EMC effect in light nuclei  

SciTech Connect (OSTI)

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.

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

2009-12-17T23:59:59.000Z

252

Relativistic mean field calculations in neutron-rich nuclei  

SciTech Connect (OSTI)

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.

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

253

Particle Identification in the NIMROD-ISiS Detector Array  

E-Print Network [OSTI]

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.

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

2009-03-04T23:59:59.000Z

254

Particle Identification in the NIMROD-ISiS Detector Array  

SciTech Connect (OSTI)

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.

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

255

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

E-Print Network [OSTI]

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.

J. Terasaki; J. Engel

2011-05-19T23:59:59.000Z

256

Nuclear diagnostic for fast alpha particles  

DOE Patents [OSTI]

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.

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

257

Electromagnetic Studies of Mesons, Nucleons, and Nuclei  

SciTech Connect (OSTI)

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.

Baker, Oliver K.

2013-08-20T23:59:59.000Z

258

Charge Radii of beta-Stable Nuclei  

E-Print Network [OSTI]

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.

G. K. Nie

2005-12-07T23:59:59.000Z

259

Nuclear structure/nuclei far from stability  

SciTech Connect (OSTI)

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.

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

260

Magnetic Moments of Light Nuclei from Lattice Quantum Chromodynamics  

E-Print Network [OSTI]

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 ...

Beane, S.?R.

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Progress and challenges in the theory of nuclei  

E-Print Network [OSTI]

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.

D. J. Dean

2007-09-04T23:59:59.000Z

262

Application of chiral nuclear forces to light nuclei  

E-Print Network [OSTI]

In these proceedings, we discuss the current status of nuclear bound state predictions based on chiral nuclear interactions. Results of ordinary $s$- and $p$-shell nuclei and light hypernuclei are shown.

A. Nogga

2007-12-20T23:59:59.000Z

263

The variability of warm absorbers in Active Galactic Nuclei  

E-Print Network [OSTI]

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 ...

Gibson, Robert R. (Robert Ross)

2006-01-01T23:59:59.000Z

264

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

SciTech Connect (OSTI)

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.

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

265

Scissors mode of Gd nuclei studied from resonance neutron capture  

SciTech Connect (OSTI)

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.

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

266

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

E-Print Network [OSTI]

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 ...

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

2015-01-01T23:59:59.000Z

267

The Production and Study of Neutron-rich Nuclei  

SciTech Connect (OSTI)

Over the last few years there has been a great increase in our knowledge of neutron-rich nuclei resulting from the use of large {gamma}-ray arrays to investigate prompt {gamma} rays from fission and deep inelastic reactions. In this paper we shall discuss various aspects of the physics underling the fission and deep-inelastic reaction mechanisms that are relevant to the spectroscopic investigation of neutron-rich nuclei.

Durell, J.L.

1999-12-31T23:59:59.000Z

268

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

E-Print Network [OSTI]

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.

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

269

Electric Dipole Moments of Neutron-Odd Nuclei  

E-Print Network [OSTI]

The electric dipole moments (EDMs) of neutron-odd nuclei with even protons are systematically evaluated. We first derive the relation between the EDM and the magnetic moment operators by making use of the core polarization scheme. This relation enables us to calculate the EDM of neutron-odd nuclei without any free parameters. From this calculation, one may find the best atomic system suitable for future EDM experiments.

Takehisa Fujita; Sachiko Oshima

2011-02-15T23:59:59.000Z

270

Energy systematics of heavy nuclei -- mean field models in comparison  

E-Print Network [OSTI]

We compare the systematics of binding energies computed within the standard and extended versions of the relativistic mean-field (RMF) model and the Skyrme Hartree-Fock (SHF) model. The general trends for the binding energies for super-heavy nuclei are significantly different for these models. The SHF models tend to underbind the superheavy nuclei, while, RMF models show just the opposite trend. The extended RMF model seems to provide remarkable improvements over the results obtained for the standard RMF model.

P. -G. Reinhard; B. K. Agrawal

2010-12-10T23:59:59.000Z

271

A study of particle generation during laser ablation withapplications  

SciTech Connect (OSTI)

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.

Liu, Chunyi

2005-08-12T23:59:59.000Z

272

EMC effect for light nuclei: new results from Jefferson Lab  

SciTech Connect (OSTI)

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.

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

2011-10-24T23:59:59.000Z

273

EMC effect for light nuclei: New results from Jefferson Lab  

SciTech Connect (OSTI)

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.

Aji Daniel

2011-10-01T23:59:59.000Z

274

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

E-Print Network [OSTI]

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.

Alexander J. Silenko

2014-06-09T23:59:59.000Z

275

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

SciTech Connect (OSTI)

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.

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

2014-10-31T23:59:59.000Z

276

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

SciTech Connect (OSTI)

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.

Loaiza, D.J.

1998-03-01T23:59:59.000Z

277

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

SciTech Connect (OSTI)

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.

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

2002-06-01T23:59:59.000Z

278

An ergonomically designed lavatory counter and sink area for the independent elderly user  

E-Print Network [OSTI]

inches. For the wheelchair group, 22. 0 inches should be used as the maximum depth of the counter. Concerning lavatory faucets, the two handled faucet with surgical (wrist-action) paddies was rated better than the other types tested. The single lever... AND RECOMMENDATIQNS. . . 51 Design Recomendations. Limitations and Recommendations for Future Research. . 64 REFERENCES. . 67 APPENDIX A: QUESTIONNAIRE 8: INSTRUMENT TO OBTAIN INFORMATION CONSENT. . . . . . . 72 C: FAUCET EVALUATION SCALE. D: FAUCET...

Barron, Michael Kevin

1986-01-01T23:59:59.000Z

279

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

SciTech Connect (OSTI)

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.

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

2001-01-17T23:59:59.000Z

280

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

SciTech Connect (OSTI)

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.

Janas, Zenon

2000-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Dynamics of Carroll Particles  

E-Print Network [OSTI]

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.

Eric Bergshoeff; Joaquim Gomis; Giorgio Longhi

2014-05-31T23:59:59.000Z

282

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

E-Print Network [OSTI]

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...

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

283

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

E-Print Network [OSTI]

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.

I. Adachi et al

1994-12-13T23:59:59.000Z

284

Non-Axial Octupole Deformations and Tetrahedral Symmetry in Heavy Nuclei  

SciTech Connect (OSTI)

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.

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

285

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

SciTech Connect (OSTI)

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.

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

286

Particle Physics Booklet 2008  

E-Print Network [OSTI]

212 25. Accelerator physics of colliders ? 26. High-energythe full Review. PARTICLE PHYSICS BOOKLET TABLE OF CONTENTSrev. ) Summary Tables of Particle Physics Gauge and Higgs

et al., C. Amsler

2008-01-01T23:59:59.000Z

287

Study of Nuclei and Elementary Particles At Low and Intermediate Energies  

SciTech Connect (OSTI)

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.

Robert D. McKeown

2013-02-27T23:59:59.000Z

288

Neutrinoless double beta decay in deformed nuclei: its implications in particle and nuclear physics .  

E-Print Network [OSTI]

??In my thesis, we calculated the Nuclear Matrix Elements (NME) for neutrinoless double beta decay (0??? decay). Neutrinoless double beta decay is a rare nuclear… (more)

Fang, DongLiang

2011-01-01T23:59:59.000Z

289

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

E-Print Network [OSTI]

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 ...

Bethke, Kristen (Kristen Ann)

2005-01-01T23:59:59.000Z

290

Quantitative analysis of caregiver comprehension of children's over-the-counter cough and cold medication dosing instructions.  

E-Print Network [OSTI]

??The Food and Drug Administration maintains the authority to regulate the labeling of children’s over-the-counter cough and cold medications. FDA’s primary interests in this area… (more)

Gaynor, Melissa Robyn

2011-01-01T23:59:59.000Z

291

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

SciTech Connect (OSTI)

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.

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

292

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

293

Tidal Waves -- a non-adiabatic microscopic description of the yrast states in near-spherical nuclei  

E-Print Network [OSTI]

The yrast states of nuclei that are spherical or weakly deformed in their ground states are described as quadrupole waves running over the nuclear surface, which we call "tidal waves". The energies and E2 transition probabilities of the yrast states in nuclides with $Z$= 44, 46, 48 and $N=56, ~58,..., 66$ are calculated by means of the cranking model in a microscopic way. The nonlinear response of the nucleonic orbitals results in a strong coupling between shape and single particle degrees of freedom.

S. Frauendorf; Y. Gu; J. Sun

2011-09-08T23:59:59.000Z

294

Improving single slope ADC and an example implemented in FPGA with 16.7 GHz equivalent counter clook frequency  

SciTech Connect (OSTI)

Single slope ADC is a common building block in many ASCI or FPGA based front-end systems due to its simplicity, small silicon footprint, low noise interference and low power consumption. In single slope ADC, using a Gray code counter is a popular scheme for time digitization, in which the comparator output drives the clock (CK) port of a register to latch the bits from the Gray code counter. Unfortunately, feeding the comparator output into the CK-port causes unnecessary complexities and artificial challenges. In this case, the propagation delays of all bits from the counter to the register inputs must be matched and the counter must be a Gray code one. A simple improvement on the circuit topology, i.e., feeding the comparator output into the D-port of a register, will avoid these unnecessary challenges, eliminating the requirement of the propagation delay match of the counter bits and allowing the use of regular binary counters. This scheme not only simplifies current designs for low speeds and resolutions, but also opens possibilities for applications requiring higher speeds and resolutions. A multi-channel single slope ADC based on a low-cost FPGA device has been implemented and tested. The timing measurement bin width in this work is 60 ps, which would need a 16.7 GHz counter clock had it implemented with the conventional Gray code counter scheme. A 12-bit performance is achieved using a fully differential circuit making comparison between the input and the ramping reference, both in differential format.

Wu, Jinyuan; /Fermilab; Odeghe, John; /South Carolina State U.; Stackley, Scott; /Boston U.; Zha, Charles; /Rice U.

2011-11-01T23:59:59.000Z

295

Production of thorium-229 using helium nuclei  

DOE Patents [OSTI]

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.

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

2010-12-14T23:59:59.000Z

296

The quest for novel modes of excitation in exotic nuclei  

E-Print Network [OSTI]

This article provides an insight into several open problems in the quest for novel modes of excitation in nuclei with isospin asymmetry, deformation and finite temperature characteristic in stellar environment. Major unsolved problems include the nature of pygmy dipole resonances, the quest for various multipole and spin-isospin excitations both in neutron-rich and proton drip-line nuclei mainly driven by loosely bound nucleons, excitations in unstable deformed nuclei and evolution of their properties with the shape phase transition. Exotic modes of excitation in nuclei at finite temperatures characteristic for supernova evolution present open problems with possible impact in modeling astrophysically relevant weak interaction rates. All these issues challenge self-consistent many body theory frameworks at the frontiers of on-going research, including nuclear energy density functionals, both phenomenological and constrained by the strong interaction physics of QCD, models based on low-momentum two-nucleon interaction V_{low-k} and correlated realistic nucleon-nucleon interaction V_{UCOM}, supplemented by three-body force, as well as two-nucleon and three-nucleon interactions derived from the chiral effective field theory. Joined theoretical and experimental efforts, including research with radioactive isotope beams, are needed to provide insight into dynamical properties of nuclei away from the valley of stability, involving the interplay of isospin asymmetry, deformation and finite temperature.

N. Paar

2010-02-25T23:59:59.000Z

297

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

SciTech Connect (OSTI)

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.

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

298

Solar neutrino physics: Sensitivity to light dark matter particles  

E-Print Network [OSTI]

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.

Ilidio Lopes; Joseph Silk

2013-09-29T23:59:59.000Z

299

Structure of nuclei at extreme values of the isospin  

E-Print Network [OSTI]

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.

J. Dobaczewski

1999-01-14T23:59:59.000Z

300

Light radioactive nuclei capture reactions with phenomenological potential models  

E-Print Network [OSTI]

Light radioactive nuclei play an important role in many astrophysical environments. Due to very low cross sections of some neutron and proton capture reactions by these radioactive nuclei at energies of astrophysical interest, direct laboratory measurements are very difficult. For radioactive nuclei such as 8Li and 8B, the direct measurement of neutron capture reactions is impossible. Indirect methods have been applied to overcome these difficulties. In this work we will report on the results and discussion of phenomenological potential models used to determine some proton and neutron capture reactions. As a test we show the results for the 16O(p,g)17F_gs(5/2+) and 16O(p,g)17F_ex(1/2+) capture reactions.We also computed the nucleosynthesis cross sections for the 7Li(n,g)8Li, 8Li(n,g)9Li and 8B(p,g)9C capture reactions.

V. Guimaraes; C. A. Bertulani

2009-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Formation of superheavy nuclei in cold fusion reactions  

E-Print Network [OSTI]

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.

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

2007-01-01T23:59:59.000Z

302

Formation of superheavy nuclei in cold fusion reactions  

E-Print Network [OSTI]

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.

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

2007-10-17T23:59:59.000Z

303

JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei  

SciTech Connect (OSTI)

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.

Papenbrock, Thomas

2014-05-16T23:59:59.000Z

304

Exotic modes of excitation in proton rich nuclei  

SciTech Connect (OSTI)

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.

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

2011-11-30T23:59:59.000Z

305

Proton and Neutron Momentum Distributions in A = 3 Asymmetric Nuclei  

E-Print Network [OSTI]

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.

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

2014-10-16T23:59:59.000Z

306

Laser particle sorter  

DOE Patents [OSTI]

Method and apparatus are provided for sorting particles, such as biological particles. A first laser is used to define an optical path having an intensity gradient which is effective to propel the particles along the path but which is sufficiently weak that the particles are not trapped in an axial direction. A probe laser beam is provided for interrogating the particles to identify predetermined phenotypical characteristics of the particles. A second laser beam is provided to intersect the driving first laser beam, wherein the second laser beam is activated by an output signal indicative of a predetermined characteristic. The second laser beam is switchable between a first intensity and a second intensity, where the first intensity is effective to displace selected particles from the driving laser beam and the second intensity is effective to propel selected particles along the deflection laser beam. The selected particles may then be propelled by the deflection beam to a location effective for further analysis. 2 figs.

Martin, J.C.; Buican, T.N.

1987-11-30T23:59:59.000Z

307

Simulation and Analysis of a Tissue Equivalent Proportional Counter Using the Monte Carlo Transport Code FLUKA  

E-Print Network [OSTI]

). Accurate codes are desirable because of the high cost of beam time at accelerators that can produce particles with charge and velocity that simulate cosmic rays. They are currently used for a variety of engineering and analysis applications, but full... of the incident ionizing particle (excluding rest energy), Eout is the sum of the energies of all ionizing particles leaving the interaction (excluding rest energy) and Q is the change in rest energies of the nucleus and of all particles involved...

Northum, Jeremy Dell

2011-08-08T23:59:59.000Z

308

The monitoring system for the aerogel Cherenkov counter of the BELLE detector  

E-Print Network [OSTI]

We report on a design and performances of a monitoring system developed for the aerogel Cherenkov counters (ACC) of the BELLE detector. The system consists of blue LEDs, a diffuser box, and optical distributors which distribute the LED light to the ACC modules. The employed LED (NSPB series) has been observed to have high reliability on the long term stability and the temprature dependence. The diffuser box is employed to reduce the intrinsic non-uniformity of the LED light intensity. The overall performances of the present monitoring system on uniformity and intensity of the light output have been found to satisfy all the requirements for the monitoring.

M. H. R. Khan; A. Murakami; T. Sumiyoshi; T. Kuniya; I. Adachi; R. Enomoto; H. Hattori; T. Iijima; K. Kaneda; R. Kawabata; T. Ooba; R. Suda; K. Suzuki; M. Watanabe

1998-03-27T23:59:59.000Z

309

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

E-Print Network [OSTI]

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.

Vladimir Kozlov; Nikolay Kuznetsov

2014-06-05T23:59:59.000Z

310

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

E-Print Network [OSTI]

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.

Jiro Soda

2014-10-31T23:59:59.000Z

311

E-Print Network 3.0 - asymmetric colliding nuclei Sample Search...  

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

colliding nuclei Search Powered by Explorit Topic List Advanced Search Sample search results for: asymmetric colliding nuclei Page: << < 1 2 3 4 5 > >> 1 managed for the U.S....

312

Decoupling electrons and nuclei without the Born-Oppenheimer approximation  

E-Print Network [OSTI]

Decoupling electrons and nuclei without the Born-Oppenheimer approximation Patrick Cassam. The EN-GMFCI is a new paradigm for quantum chemistry that bypasses the tradi- tional Born-Oppenheimer (BO;1 Introduction The Born-Oppenheimer (BO) potential energy surface (PES) is one of the main paradigm of quantum

Paris-Sud XI, Université de

313

Coherent dissociation of relativistic {sup 12}N nuclei  

SciTech Connect (OSTI)

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.

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

314

Folding model description of reactions with exotic nuclei  

SciTech Connect (OSTI)

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.

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

315

General Properties of Fermi/LAT Active Galactic Nuclei  

E-Print Network [OSTI]

The Second Catalog of Blazars and other Active Galactic Nuclei detected by the Fermi/LAT (2LAC) includes about 1100 sources, 886 of which comprise the Clean Sample. The general properties of the different populations of sources classified according to the strength of their emission lines (FSRQs, BL Lacs) or the estimated position of the synchrotron peak are reviewed.

Lott, B; Cutini, S; Gasparrini, D; Dermer, C D

2012-01-01T23:59:59.000Z

316

Trends in the study of light proton rich nuclei  

SciTech Connect (OSTI)

Recent work in light proton-rich nuclei is reviewed. Evidence for the first T/sub z/ = -5/2 nuclide, /sup 35/Ca, is presented. The mechanisms of two-proton emission following beta-decay is investigated. Future directions in this field are discussed. 23 refs., 5 figs. (WRF)

Moltz, D.M.; Aysto, J.; Hotchkis, M.A.C.; Cerny, J.

1985-09-01T23:59:59.000Z

317

Statistical Spectroscopy for Neutron-rich sd-Shell Nuclei  

E-Print Network [OSTI]

Statistical spectroscopic results using the spectral distribution theory are obtained for the structure of neutron-rich light nuclei going towards the drip line and compared to experimental values available. These results will be useful for nuclear astrophysics problems where often averaged nuclear properties are adequate.

Kamales Kar

2012-08-14T23:59:59.000Z

318

Nuclear induced breakup of halo nuclei H. Esbensen  

E-Print Network [OSTI]

energies. The description of breakup reactions at low beam energies is much more difficult because one, which is the conventional method used to describe low-energy, heavy-ion reactions of ordinary nuclei treatment is much larger than the exact result. This trend is also indicated at low energy by comparing

Bertsch George F.

319

THE STRUCTURE AND REACTIONS OF NEUTRON-RICH NUCLEI  

E-Print Network [OSTI]

dissociation experiments 351 2.3. Low-energy behaviour of "Li dissociation cross 6.2. Direct measurements 355 of the understanding of the structure and reactions of neutron-rich nuclei. The properties of the low-lying soft giant and total nuclear reaction cross section isalso calculated using the microscopic tp, p 2-Glauber theory

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

320

Scattering of light nuclei S. Quaglioni1,a  

E-Print Network [OSTI]

nuclear reactions. Indeed, low-energy fusion reactions represent the primary energy-generation mech- anism in the ab initio calculation of low-energy scattering of light nuclei. 1.1 Overview of reaction approaches physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum

Roth, Robert

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

THE VELA PULSAR AND ITS LIKELY COUNTER-JET IN THE K{sub s} BAND  

SciTech Connect (OSTI)

We report the first high spatial resolution near-infrared (near-IR) imaging of the Vela pulsar in the K{sub s} band obtained with the new adaptive optics system recently mounted on the Gemini-South telescope. For the first time, we have firmly detected the pulsar in this band with K{sub s} ? 21.8 mag, and have resolved in detail an extended feature barely detected previously in the immediate vicinity of the pulsar in the J{sub s}H bands. The pulsar K{sub s} flux is fully consistent with the extension of the flat optical spectrum of the pulsar toward the IR and does not confirm the strong IR flux excess in the pulsar emission suggested earlier by the low spatial resolution data. The extended feature is about two times brighter than the pulsar and is likely associated with its X-ray counter-jet. It extends ?2'' southward of the pulsar along the X-ray counter-jet and shows knot-like structures and a red spectrum.

Zyuzin, D.; Shibanov, Yu.; Danilenko, A. [Ioffe Physical Technical Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Mennickent, R. E. [Department of Astronomy, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile); Zharikov, S. [Observatorio Astronómico Nacional SPM, Instituto de Astronomía, UNAM, Ensenada, BC (Mexico)

2013-10-01T23:59:59.000Z

322

Spin-dependent scattering and absorption of thermal neutrons on dynamically polarized nuclei  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

323

Effect of Nuclei Concentration on Cavitation Cluster Dynamics C.D. Ohl, and D. Lohse  

E-Print Network [OSTI]

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

Ohl, Claus-Dieter

324

New measurements of high-momentum nucleons and short-range structures in nuclei  

E-Print Network [OSTI]

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.

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

325

Energy Density Functional for Nuclei and Neutron Stars  

SciTech Connect (OSTI)

Background: Recent observational data on neutron star masses and radii provide stringent constraints on the equation of state of neutron rich matter [ Annu. Rev. Nucl. Part. Sci. 62 485 (2012)]. Purpose: We aim to develop a nuclear energy density functional that can be simultaneously applied to finite nuclei and neutron stars. Methods: 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. Results: The new functional TOV-min yields results for nuclear bulk properties (energy, rms radius, diffraction radius, and 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 208Pb and the neutron star radius. Conclusions: 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. This functional is expected to yield more reliable predictions in the region of very neutron rich heavy nuclei.

Erler, J. [UTK/ORNL/German Cancer Research Center-Heidelberg; Horowitz, C. J. [UTK/ORNL/Indiana University; Nazarewicz, Witold [UTK/ORNL/University of Warsaw; Rafalski, M. [UTK/ORNL; Reinhard, P.-G. [Universitat Erlangen, Germany

2013-01-01T23:59:59.000Z

326

Microscopic description of neutron emission rates in compound nuclei  

E-Print Network [OSTI]

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.

Yi Zhu; Junchen Pei

2014-11-02T23:59:59.000Z

327

The Role of Density Dependent One-Body Momentum Distribution on the Calculation of Ground State Properties of Closed Shell Nuclei  

E-Print Network [OSTI]

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...

Mariji, Hodjat

2015-01-01T23:59:59.000Z

328

Energy and Mass Dependences of the Parameters of the Semimicroscopic Folding Model for Alpha Particles at Low and Intermediate Energies  

SciTech Connect (OSTI)

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.

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

329

Volcanic particle aggregation in explosive eruption columns. Part I: Parameterization of the microphysics of hydrometeors and ash  

E-Print Network [OSTI]

, 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

Rose, William I.

330

Adhesive particle shielding  

DOE Patents [OSTI]

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.

Klebanoff, Leonard Elliott (Dublin, CA); Rader, Daniel John (Albuquerque, NM); Walton, Christopher (Berkeley, CA); Folta, James (Livermore, CA)

2009-01-06T23:59:59.000Z

331

Simulation of particle agglomeration using dissipative particle dynamics  

E-Print Network [OSTI]

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...

Mokkapati, Srinivas Praveen

2009-05-15T23:59:59.000Z

332

Opposite charged two-body system of identical counter-rotating black holes  

E-Print Network [OSTI]

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).

I. Cabrera-Munguia; Claus Lämmerzahl; L. A. López; Alfredo Macías

2014-05-12T23:59:59.000Z

333

Coherent Control of Resonant Two-Photon Transitions by Counter-Propagating Ultrashort Pulse Pairs  

E-Print Network [OSTI]

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...

Lee, Woojun; Kim, Kyungtae; Ahn, Jaewook

2015-01-01T23:59:59.000Z

334

Development of a Large-Area Aerogel Cherenkov Counter Onboard BESS  

E-Print Network [OSTI]

This paper describes the development of a threshold type aerogel Cherenkov counter with a large sensitive area of 0.6 m$^2$ to be carried onboard the BESS rigidity spectrometer to detect cosmic-ray antiprotons. The design incorporates a large diffusion box containing 46 finemesh photomultipliers, with special attention being paid to achieving good performance under a magnetic field and providing sufficient endurance while minimizing material usage. The refractive index of the aerogel was chosen to be 1.03. By utilizing the muons and protons accumulated during the cosmic-ray measurements at sea level, a rejection factor of 10$^4$ was obtained against muons with $\\beta \\approx 1$, while keeping 97% efficiency for protons below the threshold.

Y. Asaoka; K. Abe; K. Yoshimura; M. Ishino; M. Fujikawa; S. Orito

1998-05-01T23:59:59.000Z

335

Methodology for the use of proportional counters in pulsed fast neutron yield measurements  

E-Print Network [OSTI]

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...

Tarifeńo-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo

2011-01-01T23:59:59.000Z

336

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]

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.

Lakshmidhar Satpathy

337

The trigger, as given by the scintillator barrel counters, results from two counters (one in the upper and one in the lower part of the barrel) which have been hit by a particle  

E-Print Network [OSTI]

from the depleted uranium inside the hadron calorimeter, the production of delta-rays (knock and is the counts-to-time conversion constant (i.e. bin-size) of the TDC. The cosmic-ray muon trigger does

van Suijlekom, Walter

338

Scintillation counter and wire chamber front end modules for high energy physics experiments  

SciTech Connect (OSTI)

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.

Baldin, Boris; DalMonte, Lou; /Fermilab

2011-01-01T23:59:59.000Z

339

A Single Tower Configuration of the Modular Gamma Box Counter System - 13392  

SciTech Connect (OSTI)

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)

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

340

Role of shapes in the identification of superheavy nuclei  

SciTech Connect (OSTI)

The synthesis and identification of superheavy nuclei have taken a dramatic turn recently with the emergence of hot fusion reactions. Such new methods have enabled the synthesis and identification of superheavy elements with Z=114-116 and 118. The identification of such elements is mainly done by observing their {alpha}-decay chains terminating with spontaneous fission events. In such studies, the role played by the shapes of superheavy elements has assumed great significance. In this work, we use the Shanmugam-Kamalaharan model for {alpha} decay, which is versatile in accounting for the shapes and deformations of the parent and the daughter nuclei as well as the charge redistribution (also termed charge equilibration) process during the decay. Our calculations turn out to be very useful for the identification of superheavy elements.

Shanmugam, G.; Sudhakar, S.; Niranjani, S. [SK Institute of Higher Studies, S-2, Lotus Colony, Nandanam, Chennai - 600 035 (India)

2005-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Magnetic Moments of Light Nuclei from Lattice Quantum Chromodynamics  

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

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.

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

342

Delta resonance and nonlocal effects in pion photoproduction from nuclei  

SciTech Connect (OSTI)

The photoproduction of charged pions from light nuclei is investigated in a distorted wave impulse approximation carried out in momentum space. This permits a straightforward inclusion of nonlocal terms in the pion production operator such as that of Blomqvist and Laget. The interaction of the outgoing pion with the residual nuclear state is described by the optical potential of Stricker, McManus, and Carr. The cross section for pion production from p-shell nuclei is decomposed into partial cross sections labeled by transition angular momenta and spin which are almost independent of nuclear structure. Using the reaction /sup 13/C(..gamma..,..pi../sup -/) /sup 13/N /sup g.s./, the effects of the delta isobar in the production operator on these partial cross sections is investigated. The same reaction is used to demonstrate the inadequacy of local coordinate space analyses.

Tiator, L.; Wright, L.E.

1984-09-01T23:59:59.000Z

343

Unresolved issues in the search for eta-mesic nuclei  

E-Print Network [OSTI]

Even if the theoretical definition of an unstable state is straightforward, its experimental identification often depends on the method used in the analysis and extraction of data. A good example is the case of eta mesic nuclei where strong hints of their existence led to about three decades of extensive theoretical and experimental searches. Considering the still undecided status of these states and the limitations in the understanding of the eta-nucleon as well as the eta-nucleus interaction, the present article tries to look back at some unresolved problems in the production mechanism and final state interaction of the eta mesons and nuclei. An unconventional perspective which provides a physical insight into the nature of the eta-nucleus interaction is also presented using quantum time concepts.

Kelkar, N G

2015-01-01T23:59:59.000Z

344

Density dependence of symmetry free energy of hot nuclei  

E-Print Network [OSTI]

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.

S. K. Samaddar; J. N. De; X. Vinas; M. Centelles

2008-09-04T23:59:59.000Z

345

Energy density functional for nuclei and neutron stars  

E-Print Network [OSTI]

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.

J. Erler; C. J. Horowitz; W. Nazarewicz; M. Rafalski; P. -G. Reinhard

2012-11-27T23:59:59.000Z

346

Production of $?$ and $?'$ Mesons on Nucleons and Nuclei  

E-Print Network [OSTI]

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.

B. Krusche; C. Wilkin

2014-10-28T23:59:59.000Z

347

Density matrix renormalization group and wave function factorization for nuclei  

E-Print Network [OSTI]

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.

T. Papenbrock; D. J. Dean

2005-07-15T23:59:59.000Z

348

Mid-Infrared Spectroscopic Diagnostics of Galactic Nuclei  

E-Print Network [OSTI]

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.

Vassilis Charmandaris; the Spitzer/IRS Instrument Team

2006-07-13T23:59:59.000Z

349

The distribution of nuclear quantum states in cold'' rotating nuclei  

SciTech Connect (OSTI)

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.

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

350

Coherence effects in deep inelastic scattering from nuclei  

SciTech Connect (OSTI)

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.

Ver Steeg, G. L. (Greg L.); Raufeisen, J. (Jorg)

2001-01-01T23:59:59.000Z

351

P-odd and P-even correlations for third particles in ternary fission  

SciTech Connect (OSTI)

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.

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

352

Morphology control and characterization of single-walled carbon nanotube counter electrodes in dye sensitized solar cells  

E-Print Network [OSTI]

of the sol Counter electrode ISC[mA/cm2 ] V [V] FF PCE[%] Table 1 I-VSWNT PtISC, mA/cm2 (FF : fill factor) (PCE : power conversion efficiency) ISCFF SWNTPt SWNTPt PtISC SWNT Pt SWNT PCE SWNTFTO VOC V 0.66 V

Maruyama, Shigeo

353

Modulational instability of two pairs of counter-propagating waves and energy exchange in two-component media  

E-Print Network [OSTI]

Modulational instability of two pairs of counter-propagating waves and energy exchange in two-propagating waves in two-component media is considered within the framework of two generally nonintegrable coupled Sine-Gordon equations. We consider the dynamics of weakly nonlinear wave packets, and using

354

Application of Vertically-Aligned SWNT Films for the Counter Electrode of Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

Application of Vertically-Aligned SWNT Films for the Counter Electrode of Dye-Sensitized Solar a solar cell in which VA-SWNT films were used for a CE, in place of conventional sputtered Pt on fluorine to use vertically aligned single-walled carbon nanotube (VA-SWNT) films [1] synthesized by ACCVD method

Maruyama, Shigeo

355

On Using Reputations in Ad hoc Networks to Counter Malicious Nodes Prashant Dewan, Partha Dasgupta and Amiya Bhattacharya  

E-Print Network [OSTI]

On Using Reputations in Ad hoc Networks to Counter Malicious Nodes Prashant Dewan, Partha Dasgupta, partha, amiya}@asu.edu Abstract Nodes in mobile ad hoc networks have a limited trans- mission range for ad hoc networks. Instead of choosing the shortest path to the destination, the source node chooses

Dasgupta, Partha

356

Calibration of a long counter for fast neutrons with energies from 2 to 14 MeV  

E-Print Network [OSTI]

To determine if a Hansen and McKibben type shielded long counter has a flat response from 2 MeV to 14 Mev detector efficiency was experimentally measured using a PuBe source. Calculations using the Monte Carlo program, MCNP, were performed...

Orr, Michael Lee

2012-06-07T23:59:59.000Z

357

First result of the experimental search for the 2K-capture of Xe-124 with the copper proportional counter  

E-Print Network [OSTI]

First result of experiment for searching of 2K-capture of Xe-124 with the large-volume copper proportional counter is given. The 12 litre sample with 63.3% (44 g) of Xe-124 was used in measurements. The limit on the half-life of Xe-124 with regard to 2K(2\

Yu. M. Gavrilyuk; A. M. Gangapshev; V. V. Kazalov; V. V. Kuzminov; S. I. Panasenko; S. S. Ratkevich; D. A. Tekueva; S. P. Yakimenko

2014-04-22T23:59:59.000Z

358

Families of subcritical spirals in highly counter-rotating Taylor-Couette flow Alvaro Meseguer,1,* Fernando Mellibovsky,1  

E-Print Network [OSTI]

Families of subcritical spirals in highly counter-rotating Taylor-Couette flow Alvaro Meseguer,1 identified: short axial wavelength subcritical spirals ascribed to centrifugal mechanisms and large axial.20.Ft, 47.35. i I. INTRODUCTION Subcritical transition to turbulence in shear flows has been studied

Meseguer, Alvaro

359

Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind  

E-Print Network [OSTI]

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

Dabiri, John O.

360

NBB Enclosed Particle Receiver  

Broader source: Energy.gov (indexed) [DOE]

rigorous NREL and recipient subcontracting processes. Goal: This project will develop a near-blackbody particle receiver and an integrated fluidized-bed heat exchanger to achieve...

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

A counter-charge layer in generalized solvents framework for electrical double layers in neat and hybrid ionic liquid electrolytes  

SciTech Connect (OSTI)

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.

Huang, Jingsong [ORNL; Feng, Guang [Clemson University; Sumpter, Bobby G [ORNL; Qiao, Rui [ORNL; Meunier, Vincent [ORNL

2011-01-01T23:59:59.000Z

362

Complementary optical-potential analysis of alpha-particle elastic scattering and induced reactions at low energies  

E-Print Network [OSTI]

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.

M. Avrigeanu; A. C. Obreja; F. L. Roman; V. Avrigeanu; W. von Oertzen

2008-08-05T23:59:59.000Z

363

RESEARCH IN PARTICLE PHYSICS  

SciTech Connect (OSTI)

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.

Kearns, Edward [Boston Universiy] [Boston Universiy

2013-07-12T23:59:59.000Z

364

Pileup Per Particle Identification  

E-Print Network [OSTI]

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.

Daniele Bertolini; Philip Harris; Matthew Low; Nhan Tran

2014-09-30T23:59:59.000Z

365

Imaging alpha particle detector  

DOE Patents [OSTI]

A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

Anderson, D.F.

1980-10-29T23:59:59.000Z

366

Imaging alpha particle detector  

DOE Patents [OSTI]

A method and apparatus for detecting and imaging alpha particles sources is described. A conducting coated high voltage electrode (1) and a tungsten wire grid (2) constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source (3) to be quantitatively or qualitatively analyzed. A thin polyester film window (4) allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

Anderson, David F. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

367

Inertial particle trapping in an open vortical flow  

E-Print Network [OSTI]

Recent numerical results on advection dynamics have shown that particles denser than the fluid can remain trapped indefinitely in a bounded region of an open fluid flow. Here, we investigate this counterintuitive phenomenon both numerically and analytically to establish the conditions under which the underlying particle-trapping attractors can form. We focus on a two-dimensional open flow composed of a pair of vortices and its specular image, which is a system we represent as a vortex pair plus a wall along the symmetry line. Considering particles that are much denser than the fluid, we show that two point attractors form in the neighborhood of the vortex pair provided that the particle Stokes number is smaller than a critical value of order unity. In the absence of the wall, the boundaries of the basins of the attracting points are smooth. When the wall is present, the point attractors describe counter-rotating ellipses in this frame, with a period equal to half the period of one isolated vortex pair. However, their boundaries are shown to become fractal if the distance to the wall is smaller than a critical distance that scales with the inverse square root of the Stokes number. This transformation is related to the breakdown of a separatrix that gives rise to a heteroclinic tangle close to the vortices, which we describe using a Melnikov function. For an even smaller distance to the wall, we demonstrate that a second separatrix breaks down and a new heteroclinic tangle forms farther away from the vortices. Particles released in the open part of the flow can approach the attractors and be trapped permanently provided that they cross the two separatrices. Furthermore, the trapping of heavy particles from the open flow is shown to be robust to the presence of gravity, viscosity, and noise.

Jean-Regis Angilella; Rafael D. Vilela; Adilson E. Motter

2014-03-28T23:59:59.000Z

368

Low-temperature Bessel beam trap for single submicrometer aerosol particle studies  

SciTech Connect (OSTI)

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.

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

369

Determining size-specific emission factors for environmental tobacco smoke particles  

SciTech Connect (OSTI)

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.

Klepeis, Neil E.; Apte, Michael G.; Gundel, Lara A.; Sextro, Richard G.; Nazaroff, William W.

2002-07-07T23:59:59.000Z

370

Thermal properties of light nuclei from $^{12}$C+$^{12}$C fusion-evaporation reactions  

E-Print Network [OSTI]

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.

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

371

Electron scattering in isotonic chains as a probe of the proton shell structure of unstable nuclei  

E-Print Network [OSTI]

Electron scattering on unstable nuclei is planned in future facilities of the GSI and RIKEN upgrades. Motivated by this fact, we study theoretical predictions for elastic electron scattering in the N=82, N=50, and N=14 isotonic chains from very proton-deficient to very proton-rich isotones. We compute the scattering observables by performing Dirac partial-wave calculations. The charge density of the nucleus is obtained with a covariant nuclear mean-field model that accounts for the low-energy electromagnetic structure of the nucleon. For the discussion of the dependence of scattering observables at low-momentum transfer on the gross properties of the charge density, we fit Helm model distributions to the self-consistent mean-field densities. We find that the changes shown by the electric charge form factor along each isotonic chain are strongly correlated with the underlying proton shell structure of the isotones. We conclude that elastic electron scattering experiments in isotones can provide valuable information about the filling order and occupation of the single-particle levels of protons.

X. Roca-Maza; M. Centelles; F. Salvat; X. Vińas

2013-01-08T23:59:59.000Z

372

New measurements of high-momentum nucleons and short-range structures in nuclei  

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

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.

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

373

New measurements of high-momentum nucleons and short-range structures in nuclei  

E-Print Network [OSTI]

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.

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

374

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...

375

Coupled-channel optical model potential for rare earth nuclei  

E-Print Network [OSTI]

Inspired by the recent work by Dietrich et al., substantiating validity of the adiabatic assumption in coupled-channel calculations, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on statically deformed nuclei. The generalization consists in adding the coupling of the ground state rotational band, deforming the potential by introducing appropriate quadrupole and hexadecupole deformation and correcting the OMP radius to preserve volume integral of the spherical OMP. We choose isotopes of three rare-earth elements (W, Ho, Gd), which are known to be nearly perfect rotors, to perform a consistent test of our conjecture on integrated cross sections as well as on angular distributions for elastic and inelastic neutron scattering. When doing this we employ the well-established Koning-Delaroche global spherical potential and experimentally determined deformations without any adjustments. We observe a dramatically improved agreement with experimental data compared to spherical optical model calculations. The effect of changing the OMP radius to preserve volume integral is moderate but visibly improves agreement at lower incident energies. We find that seven collective states need to be considered for the coupled-channel calculations to converge. Our results for total, elastic, inelastic, and capture cross sections, as well as elastic and inelastic angular distributions are in remarkable agreement with experimental data. This result confirms that the adiabatic assumption holds and can extend applicability of the global spherical OMP to rotational nuclei in the rare-earth region, essentially without any free parameter. Thus, quite reliable coupled-channel calculations can be performed on such nuclei even when the experimental data, and consequently a specific coupled-channel potential, are not available.

M. Herman; G. P. A. Nobre; A. Palumbo; F. S. Dietrich; D. Brown; S. Hoblit

2014-02-06T23:59:59.000Z

376

Suppressed fusion cross section for neutron halo nuclei  

E-Print Network [OSTI]

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.

Makoto Ito; Kazuhiro Yabana; Takashi Nakatsukasa; Manabu Ueda

2006-01-20T23:59:59.000Z

377

Cluster approach to the structure of nuclei with Z {>=} 96  

SciTech Connect (OSTI)

The properties of alternating parity bands in heavy nuclei {sup 234}Th, {sup 239-242}U, {sup 241-245}Pu, {sup 243-248}Cm, {sup 245-250}Cf, {sup 248-251}Fm, {sup 249-254}No, {sup 253-256}Rf, and {sup 258}Sg are analyzed within the dinuclearsystem model. The model is based on the assumption that the cluster-type shapes are produced by the motion of the nuclear system in the mass-asymmetry coordinate. The energies of the low-lying states whose parity is opposite to the parity of the ground state are predicted for the first time.

Shneidman, T. M., E-mail: shneyd@theor.jinr.ru; Adamian, G. G.; Antonenko, N. V.; Jolos, R. V. [Joint Institute for Nuclear Research, Bogolyubov Laboratory of Theoretical Physics (Russian Federation)

2007-08-15T23:59:59.000Z

378

Spectropolarimetry and the Geometry of Type 1 Seyfert Nuclei  

E-Print Network [OSTI]

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.

Andy Robinson; David J. Axon; James E. Smith

2002-11-11T23:59:59.000Z

379

Pulsars: Macro-nuclei with 3-flavour symmetry  

E-Print Network [OSTI]

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.

Xu, Renxin

2015-01-01T23:59:59.000Z

380

Neutron-Neutron Correlations in the Dissociation of Halo Nuclei  

E-Print Network [OSTI]

Studies attempting to probe the spatial configuration of the valence neutrons in two-neutron halo nuclei using the technique of intensity interferometry are described. Following a brief review of the method and its application to earlier measurements of the breakup of 6He, 11Li and 14Be, the results of the analysis of a high statistics data set for 6He are presented. The limitations of the technique, including the assumption of incoherent emission in the breakup and the sensitivity to the continuum states populated in the dissociation rather than the ground state, are discussed.

N. A. Orr

2008-03-06T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Effects of Distortion on the Intercluster Motion in Light Nuclei  

SciTech Connect (OSTI)

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.

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

382

Core excitation effects in the breakup of halo nuclei  

SciTech Connect (OSTI)

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.

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

383

Giant Monopole Resonance in Transitional and Deformed-Nuclei  

E-Print Network [OSTI]

=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...

Garg, U.; Bogucki, P.; Bronson, J. D.; Lui, YW; Youngblood, David H.

1984-01-01T23:59:59.000Z

384

Excitation energy dependence of symmetry energy of finite nuclei  

E-Print Network [OSTI]

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.

S. K. Samaddar; J. N. De; X. Vinas; M. Centelles

2007-10-11T23:59:59.000Z

385

Thermalization in collisions of large nuclei at high energies  

E-Print Network [OSTI]

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).

Aleksi Kurkela

2013-03-19T23:59:59.000Z

386

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

387

E-Print Network 3.0 - atom nuclei isotopes Sample Search Results  

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

decay... the name Borromean nuclei. The heaviest neutron rich carbon ... Source: TRIUMF Isotope Separation and ACceleration (ISAC) facility, beta-NMR Group Collection: Physics 27...

388

Microscopic and self-consistent description for neutron halo in deformed nuclei  

SciTech Connect (OSTI)

A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed for the study of neutron halos in deformed nuclei and the halo phenomenon in deformed weakly bound nuclei is investigated. Magnesium and neon isotopes are studied and some results are presented for the deformed neutron-rich and weakly bound nuclei {sup 44}Mg and {sup 36}Ne. The core of the former nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.

Li Lulu [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Meng Jie [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China) and Department of Physics, University of Stellenbosch, Stellenbosch (South Africa); Zhao Enguang; Zhou Shangui [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China) and Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China)

2013-05-06T23:59:59.000Z

389

E-Print Network 3.0 - active galactic nuclei Sample Search Results  

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

Nuclei by Bradley M. Peterson (Cambridge U. Press). Course Web Page: http... phenomenology of observational cosmology and ... Source: Martini, Paul - Department of...

390

Protons hog the momentum in neutron-rich nuclei | Argonne National...  

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

a greater fraction of the protons than neutrons to have high momentum in relatively neutron-rich nuclei. The CLAS detector completely surrounds an experimental target and is...

391

Discovery of Active Galactic Nuclei in Mid- and Far-Infrared Deep Surveys with ISO  

E-Print Network [OSTI]

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.

Yoshiaki Taniguchi

2001-11-01T23:59:59.000Z

392

Superscaling in Nuclei: A Search for Scaling Function Beyond the Relativistic Fermi Gas Model  

E-Print Network [OSTI]

We construct a scaling function $f(\\psi^{\\prime})$ for inclusive electron scattering from nuclei within the Coherent Density Fluctuation Model (CDFM). The latter is a natural extension to finite nuclei of the Relativistic Fermi Gas (RFG) model within which the scaling variable $\\psi^{\\prime}$ was introduced by Donnelly and collaborators. The calculations show that the high-momentum components of the nucleon momentum distribution in the CDFM and their similarity for different nuclei lead to quantitative description of the superscaling in nuclei. The results are in good agreement with the experimental data for different transfer momenta showing superscaling for negative values of $\\psi^{\\prime}$, including those smaller than -1.

A. N. Antonov; M. K. Gaidarov; D. N. Kadrev; M. V. Ivanov; E. Moya de Guerra; J. M. Udias

2004-02-25T23:59:59.000Z

393

Coil spring conveyor for positioning an external radioactive standard in a liquid scintillation counter  

SciTech Connect (OSTI)

This patent describes a liquid scintillation counter having a counting chamber for receiving a liquid sample containing a liquid scintillator and a sample of a radioactive substance to be counted. An improved apparatus is described for positioning a radioactive source in an operating location to irradiate the liquid sample in the counting chamber comprising the combination of: (1) a flexible conveyor including an elongate, generally tubular coil spring section having an interior tubular bore configured to receive the radioactive source; (2) means for retaining the radioactive source in a predetermined axial position within the coil spring; (3) means supporting the coil spring for movement along a conveyor path between a storage location for the radioactive source remote from the counting chamber and an operating location for the radioactive source proximate the counting chamber; and (4) drive means coupled to the coil spring and operative to drive the coil spring along the conveyor path for conveying the radioactive source between the storage and operating locations.

Kampf, R.S.

1986-03-04T23:59:59.000Z

394

Controlling Low-Rate Signal Path Microdischarge for an Ultra-Low-Background Proportional Counter  

SciTech Connect (OSTI)

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.

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

395

High and low frequency instabilities driven by counter-streaming electron beams in space plasmas  

SciTech Connect (OSTI)

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.

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

396

Characterization of a Spherical Proportional Counter in argon-based mixtures  

E-Print Network [OSTI]

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.

F. J. Iguaz; A. Rodriguez; J. F. Castel; I. G. Irastorza

2015-01-07T23:59:59.000Z

397

An array of low-background 3He proportional counters for theSudbury Neutrino Observatory  

SciTech Connect (OSTI)

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.

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

398

Environmental Assessment for the new Whole Body Counter facility at the Savannah River Site  

SciTech Connect (OSTI)

The U.S. Department of Energy proposes to construct and operate a new in-vivo counting facility at the Savannah River Site for the monitoring of employees for internal radionuclides. The proposed facility, titled the new Whole Body Counter (WBC) facility, would house both the existing and additional new invivo counting equipment and facility support operations. The proposed facility would be sited and located in an area of the SRS in which background radiation levels are sufficiently low to assure accurate in-vivo counts and a location that would assure ease of access for occupational workers. This Environmental Assessment has been prepared in compliance with the National Environmental Policy Act (NEPA) of 1969, as amended, and the requirements of the Council on Environmental Quality Regulations for Implementing NEPA (40 CPR Parts 1500-1508). NEPA requires the assessment of environmental consequences of Federal actions that may affect the quality of the human environment. The proposed action has independent utility to the Savannah River operations and will be necessary to support plant activities regardless of the makeup of the future mission at the site. As such, the proposed new WBC facility is treated as part of the preliminary Reconfiguration Programmatic Environmental Impact Statement ``No Action`` alternative.

Not Available

1993-01-01T23:59:59.000Z

399

Characterization of a Spherical Proportional Counter in argon-based mixtures  

E-Print Network [OSTI]

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 th...

Iguaz, F J; Castel, J F; Irastorza, I G

2015-01-01T23:59:59.000Z

400

Big Bang Day: 5 Particles - 5. The Next Particle  

ScienceCinema (OSTI)

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.

None

2011-04-25T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Research in particle theory  

SciTech Connect (OSTI)

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.

Mansouri, F.; Suranyi, P; Wijewardhana, L.C.R.

1991-10-01T23:59:59.000Z

402

Particle Physics Masterclass  

ScienceCinema (OSTI)

Students from six local high schools -- Farmingdale, Sachem East, Shoreham, Smithtown East, Ward Melville, and William Floyd -- came to Brookhaven National Laboratory to experience research with particle physicist Helio Takai. They were among more than 6,

Helio Takai

2010-01-08T23:59:59.000Z

403

Elementary particle theory  

SciTech Connect (OSTI)

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)

Marciano, W.J.

1984-12-01T23:59:59.000Z

404

Particles in complex fluids   

E-Print Network [OSTI]

This thesis describes experimental studies of colloidal particles dispersed in solvents which themselves have phase transitions. One common definition of soft matter is: a material characterized by a mesoscopic length ...

Zand, Daniëlle D. van ’t

2010-01-01T23:59:59.000Z

405

Particle phenomenology and Maldacena  

E-Print Network [OSTI]

A brief review is offered of employing Maldacena's AdS/CFT correspondence in attempting to identify a model which extends to higher energy the standard model of particle phenomenology.

Paul H. Frampton

2008-04-18T23:59:59.000Z

406

ELEMENTARY PARTICLE INTERACTIONS  

SciTech Connect (OSTI)

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.

EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

2013-07-30T23:59:59.000Z

407

PARTICLES OF DIFFERENCE.  

SciTech Connect (OSTI)

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.

SCHWARTZ,S.E.

2000-09-21T23:59:59.000Z

408

Viability of nuclear $?$-particle condensates A reply to N.T. Zinner and A.S. Jensen, arXiv:nucl/th0712.1191  

E-Print Network [OSTI]

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).

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

2008-05-16T23:59:59.000Z

409

Delayed-fission properties of neutron-deficient americium nuclei  

SciTech Connect (OSTI)

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.

Hall, H.L. (California Univ., Berkeley, CA (USA). Dept. of Chemistry)

1989-10-23T23:59:59.000Z

410

Coupling of (ultra-) relativistic atomic nuclei with photons  

SciTech Connect (OSTI)

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.

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

411

Generalized seniority with realistic interactions in open-shell nuclei  

E-Print Network [OSTI]

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.

M. A. Caprio; F. Q. Luo; K. Cai; Ch. Constantinou; V. Hellemans

2014-08-30T23:59:59.000Z

412

Symmetry energy of deformed neutron-rich nuclei  

E-Print Network [OSTI]

The symmetry energy, the neutron pressure and the asymmetric compressibility of deformed neutron-rich even-even nuclei are calculated on the examples of Kr and Sm isotopes within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for isotopic chains of these nuclei in the framework of the self-consistent Skyrme-Hartree-Fock plus BCS method. Results for an extended chain of Pb isotopes are also presented. A remarkable difference is found in the trend followed by the different isotopic chains: the studied correlations reveal a smoother behavior in the Pb case than in the other cases. We also notice that the neutron skin thickness obtained for $^{208}$Pb with SLy4 force is found to be in a good agreement with recent data.

Gaidarov, M K; Sarriguren, P; de Guerra, E Moya

2012-01-01T23:59:59.000Z

413

Removal of pollutant compounds from water supplies using ozone, ultraviolet light, and a counter, current packed column. Master's thesis  

SciTech Connect (OSTI)

Many water pollutants are determined to be carcinogenic and often appear in very low concentrations and still pose a health risk. Conventional water treatment processes cannot remove these contaminants and there is a great demand for the development of alternative removal technologies. The use of ozone and ultraviolet light in a counter current packed column could prove to be an effective treatment process to remove these contaminants.

Kelly, E.L.

1991-01-01T23:59:59.000Z

414

GRAVITATIONAL MODEL OF HIGH-ENERGY PARTICLES IN A COLLIMATED JET  

SciTech Connect (OSTI)

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.

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

415

OBSERVATIONS OF RECENT NEW PARTICLE FORMATION IN HOUSTON DURING TEXAQS-2000.  

SciTech Connect (OSTI)

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.

BUZORIUS,G.; BRECHTEL,F.; ZELENYUK,A.; IMRE,D.; ANGEVINE,W.M.

2001-10-01T23:59:59.000Z

416

Single Particle Laser Ablation | EMSL  

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

Single Particle Laser Ablation Single Particle Laser Ablation Leads No leads are available at this time. Effect of Solar Radiation on the Optical Properties and Molecular...

417

Stimulated Raman scattering of beat wave of two counter-propagating X-mode lasers in a magnetized plasma  

SciTech Connect (OSTI)

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.

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

418

Evaluation of Counter-Based Dynamic Load Balancing Schemes for Massive Contingency Analysis on Over 10,000 Cores  

SciTech Connect (OSTI)

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.

Chen, Yousu; Huang, Zhenyu; Rice, Mark J.

2012-12-27T23:59:59.000Z

419

The neutron drip line: single-particle degrees of freedom and pairing properties as sources of theoretical uncertainties  

E-Print Network [OSTI]

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.

A. V. Afanasjev; S. E. Agbemava; D. Ray; P. Ray

2015-01-17T23:59:59.000Z

420

The neutron drip line: single-particle degrees of freedom and pairing properties as sources of theoretical uncertainties  

E-Print Network [OSTI]

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 moder...

Afanasjev, A V; Ray, D; Ray, P

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Caregivers’ perceptions and comprehension of dosage administration directions for over-the-counter cough and cold medications in children 2 to 12 years of age.  

E-Print Network [OSTI]

??Recently, over-the-counter cough and cold medication usage in children has received increased attention by the medical community, parents/caregivers and the Food and Drug Administration. Concerns… (more)

Senter, Ellene Caitlin Bagby

2010-01-01T23:59:59.000Z

422

Diesel particles -a health hazard 1 Diesel particles  

E-Print Network [OSTI]

Diesel particles - a health hazard 1 Diesel particles - a health hazard #12;The Danish Ecological Council - August 20042 Diesel particles - a health hazard ISBN: 87-89843-61-4 Text by: Christian Ege 33150777 Fax no.: +45 33150971 E-mail: info@ecocouncil.dk www.ecocouncil.dk #12;Diesel particles - a health

423

Photoproduction of mesons off light nuclei Department of Physics, University of Basel, Switzerland  

E-Print Network [OSTI]

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

Krusche, Bernd

424

Delayed and In-beam Spectroscopy on Francium and Astatine Nuclei at the Proton Drip Line  

SciTech Connect (OSTI)

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.

Uusitalo, J.; Jakobsson, U. [Department of Physics, University of Jyvaeskylae (Finland); Collaboration: RITU-Gamma Gollaboration

2011-11-30T23:59:59.000Z

425

CLOUD CONDENSATION NUCLEI IN CUMULUS HUMILIS --SELECTED CASE STUDY DURING THE CHAPS CAMPAIGN  

E-Print Network [OSTI]

CLOUD CONDENSATION NUCLEI IN CUMULUS HUMILIS -- SELECTED CASE STUDY DURING THE CHAPS CAMPAIGN X and condensation as well as activation and impact scavenging. The U.S. Department of Energy (DOE) G-1 aircraft and residuals of activated condensation cloud nuclei were conducted simultaneously. The interstitial aerosols

426

Nuclear Physics A 587 (1995) 787-801 (3He,t) reactions on unstable nuclei  

E-Print Network [OSTI]

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

Fernández de Córdoba, Pedro

427

Multicomponent density-functional theory for electrons and nuclei Thomas Kreibich  

E-Print Network [OSTI]

Multicomponent density-functional theory for electrons and nuclei Thomas Kreibich Institut fĂĽr a general multicomponent density-functional theory in which electrons and nuclei are treated completely , 71.10. w I. INTRODUCTION Density-functional theory DFT is among the most suc- cessful approaches

Gross, E.K.U.

428

FISH and Chips: Automation of Fluorescent Dot Counting in Interphase Cell Nuclei  

E-Print Network [OSTI]

) 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

van Vliet, Lucas J.

429

Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method  

E-Print Network [OSTI]

Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method G. Boutoux1 Abstract. The measurement of neutron-induced cross sections of short-lived nuclei is extremely difficult for a neutron-induced measurement. We have successfully used the surrogate reaction method to extract neutron

Boyer, Edmond

430

Binding energies and radii of N > Z nuclei in the n,p-networks model  

E-Print Network [OSTI]

A nuclear model is extended to estimate binding energies and radii of neutron-rich nuclei. These calculations have been made for some representative examples of even-Z and odd-Z nuclei with nucleon numbers lower than sixty. A comparison of results with experimental data supports the value and development of the model in nuclear studies.

I. Casinos

2009-03-09T23:59:59.000Z

431

MOLECULAR GAS IN LUMINOUS GALACTIC NUCLEI N. Z. SCOVILLE AND A. J. BAKER  

E-Print Network [OSTI]

MOLECULAR GAS IN LUMINOUS GALACTIC NUCLEI N. Z. SCOVILLE AND A. J. BAKER California Institute­wave interferometry has clearly shown the existence of enormous masses (10 9 \\Gamma 10 10 M fi ) of molecular gas. In these systems, molecular gas is an obvious source of fuel for nuclear starbursts and active galactic nuclei (AGN

Baker, Andrew J.

432

Measuring the fusion of neutron-rich light nuclei at and below the  

E-Print Network [OSTI]

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

de Souza, Romualdo T.

433

Supertwistors and massive particles  

SciTech Connect (OSTI)

In the (super)twistor formulation of massless (super)particle mechanics, the mass-shell constraint is replaced by a “spin-shell” constraint from which the spin content can be read off. We extend this formalism to massive (super)particles (with N-extended space–time supersymmetry) in three and four space–time dimensions, explaining how the spin-shell constraints are related to spin, and we use it to prove equivalence of the massive N=1 and BPS-saturated N=2 superparticle actions. We also find the supertwistor form of the action for “spinning particles” with N-extended worldline supersymmetry, massless in four dimensions and massive in three dimensions, and we show how this simplifies special features of the N=2 case. -- Highlights: •Spin-shell constraints are related to Poincaré Casimirs. •Twistor form of 4D spinning particle for spin N/2. •Twistor proof of scalar/antisymmetric tensor equivalence for 4D spin 0. •Twistor form of 3D particle with arbitrary spin. •Proof of equivalence of N=1 and N=2 BPS massive 4D superparticles.

Mezincescu, Luca, E-mail: mezincescu@server.physics.miami.edu [Department of Physics, University of Miami, Coral Gables, FL 33124 (United States); Routh, Alasdair J., E-mail: a.j.routh@damtp.cam.ac.uk [DAMTP, CMS, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Townsend, Paul K., E-mail: p.k.townsend@damtp.cam.ac.uk [DAMTP, CMS, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2014-07-15T23:59:59.000Z

434

Big Bang Day: 5 Particles - 3. The Anti-particle  

ScienceCinema (OSTI)

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". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

None

2011-04-25T23:59:59.000Z

435

Big Bang Day: 5 Particles - 3. The Anti-particle  

SciTech Connect (OSTI)

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". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

None

2009-10-07T23:59:59.000Z

436

COS DCE BOOT FSW v1.13 Component Test Results Requirement 5.2.3.3a Counters for All Commands  

E-Print Network [OSTI]

COS DCE BOOT FSW v1.13 Component Test Results Requirement 5.2.3.3a Counters for All Commands Date. Brownsberger 2-13-01 The Center for Astrophysics and Space Astronomy Reviewed: Approved: COS DCE BOOT FSW v1 Initial Release COS DCE BOOT FSW v1.13 Component Test Results Requirement 5.2.3.3a Counters for All

Colorado at Boulder, University of

437

COS DCE BOOT FSW v1.09 Component Test Results Requirement 5.2.3.3a Counter for All Commands  

E-Print Network [OSTI]

COS DCE BOOT FSW v1.09 Component Test Results Requirement 5.2.3.3a Counter for All Commands Date. Brownsberger 2-13-01 The Center for Astrophysics and Space Astronomy Reviewed: Approved: COS DCE BOOT FSW v1 Initial Release COS DCE BOOT FSW v1.09 Component Test Results Requirement 5.2.3.3a Counter for All

Colorado at Boulder, University of

438

Navigating the tension between the master narrative of the academy and the counter-narrative of reform: personal case studies from within an engineering education coalition  

E-Print Network [OSTI]

NAVIGATING THE TENSION BETWEEN THE MASTER NARRATIVE OF THE ACADEMY AND THE COUNTER- NARRATIVE OF REFORM: PERSONAL CASE STUDIES FROM WITHIN AN ENGINEERING EDUCATION COALITION A Dissertation by PRUDENCE MERTON Submitted... BETWEEN THE MASTER NARRATIVE OF THE ACADEMY AND THE COUNTER- NARRATIVE OF REFORM: PERSONAL CASE STUDIES FROM WITHIN AN ENGINEERING EDUCATION COALITION A Dissertation by PRUDENCE MERTON Submitted to the Office of Graduate Studies of Texas A...

Merton, Prudence

2006-08-16T23:59:59.000Z

439

Distribution of nanoscale nuclei in the amorphous dome of a phase change random access memory  

SciTech Connect (OSTI)

The nanoscale crystal nuclei in an amorphous Ge{sub 2}Sb{sub 2}Te{sub 5} bit in a phase change memory device were evaluated by fluctuation transmission electron microscopy. The quench time in the device (?10 ns) afforded more and larger nuclei in the melt-quenched state than in the as-deposited state. However, nuclei were even more numerous and larger in a test structure with a longer quench time (?100 ns), verifying the prediction of nucleation theory that slower cooling produces more nuclei. It also demonstrates that the thermal design of devices will strongly influence the population of nuclei, and thus the speed and data retention characteristics.

Lee, Bong-Sub, E-mail: bongsub@gmail.com; Darmawikarta, Kristof; Abelson, John R. [Department of Materials Science and Engineering and the Coordinated Sciences Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Raoux, Simone; Shih, Yen-Hao; Zhu, Yu [IBM/Macronix PCRAM Joint Project, IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Bishop, Stephen G. [Department of Materials Science and Engineering and the Coordinated Sciences Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Electrical and Computer Engineering and the Coordinated Sciences Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

2014-02-17T23:59:59.000Z

440

Charged particle accelerator grating  

DOE Patents [OSTI]

A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. 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 onto 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.

Palmer, R.B.

1985-09-09T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Precision wood particle feedstocks  

DOE Patents [OSTI]

Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

Dooley, James H; Lanning, David N

2013-07-30T23:59:59.000Z

442

Biological particle identification apparatus  

DOE Patents [OSTI]

An apparatus and method for making multiparameter light scattering measurements from suspensions of biological particles is described. Fourteen of the sixteen Mueller matrix elements describing the particles under investigation can be substantially individually determined as a function of scattering angle and probing radiations wavelength, eight elements simultaneously for each of two apparatus configurations using an apparatus which incluees, in its simplest form, two polarization modulators each operating at a chosen frequency, one polarizer, a source of monochromatic electromagnetic radiation, a detector sensitive to the wavelength of radiation employed, eight phase-sensitive detectors, and appropriate electronics. A database of known biological particle suspensions can be assembled, and unknown samples can be quickly identified once measurements are performed on it according to the teachings of the subject invention, and a comparison is made with the database.

Salzman, Gary C. (Los Alamos, NM); Gregg, Charles T. (Los Alamos, NM); Grace, W. Kevin (Los Alamos, NM); Hiebert, Richard D. (Los Alamos, NM)

1989-01-01T23:59:59.000Z

443

Carbon-particle generator  

DOE Patents [OSTI]

A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

Hunt, A.J.

1982-09-29T23:59:59.000Z

444

A Stable Massive Charged Particle  

E-Print Network [OSTI]

We consider the possibility of the existence of a stable massive charged particle by a minimal extension of the standard model particle content. Absolute stability in the case of singly charged particle is not possible if the usual doublet Higgs exists, unless a discrete symmetry is imposed.But a doubly charged particle is absolutely stable.

G. Rajasekaran

2011-06-08T23:59:59.000Z

445

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

E-Print Network [OSTI]

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 unexpectedly high rate in saltation even under conditions for which the effects of turbulence are usually believed to be small.

Thomas Pähtz; Orencio Durán; Tuan-Duc Ho; Alexandre Valance; Jasper F. Kok

2015-01-16T23:59:59.000Z

446

Perturbative Study of Energetic Particle Redistribution by Alfven Eigenmodes in ITER  

SciTech Connect (OSTI)

The modification of particle distributions by magnetohydrodynamic modes is an important topic for magnetically confined plasmas. Low amplitude modes are known to be capable of producing significant modification of injected neutral beam profiles. Flattening of a distribution due to phase mixing in an island or due to portions of phase space becoming stochastic is a process extremely rapid on the time scale of an experiment. In this paper we examine the effect of toroidal Alfven eigenmodes (TAE) and reversed shear Alfven eigenmodes (RSAE) in ITER on alpha particle and injected beam distributions using theoretically predicted mode amplitudes. It is found that for the equilibrium of a hybrid scenario even at ten times the predicted saturation level the modes have negligible effect on these distributions. A strongly reversed shear (or advanced) scenario, having a spectrum of modes that are much more global, is somewhat more susceptible to induced loss due to mode resonance, with alpha particle losses of over one percent with predicted amplitudes and somewhat larger with the assistance of toroidal field ripple. The elevated q profile contributes to stronger TAE (RSAE) drive and more unstable modes. An analysis of the existing mode-particle resonances is carried out to determine which modes are responsible for the profile modification and induced loss. We find that losses are entirely due to resonance with the counter-moving and trapped particle populations, with co-moving passing particles participating in resonances only deep within the plasma and not leading to loss.

N.N. Gorelenkov and R.B. White

2012-10-29T23:59:59.000Z

447

New evidence for triton and helion clustering in nuclei  

E-Print Network [OSTI]

Normally one plots separation energies $S_{1n}$ and $S_{2n}$ as a function of neutron number $N$ for a particular proton number $Z$ or plot $S_{1p}$ and $S_{2p}$ as a function of $Z$ for a particular $N$. Here we plot the separation energies a little differently: $S_{1n}$ and $S_{2n}$ as a function of $Z$ for a particular $N$. The same with $S_{1p}$ and $S_{2p}$ as a function of N for a particular Z. A systematic study of these new plots brings out certain very interesting generic features which clearly indicate presence of triton ("t") ${^{3}_{1} H_{2}}$ and helion ("h") ${^{3}_{2} He_{1}}$ clustering in nuclei.

Afsar Abbas

2006-12-27T23:59:59.000Z

448

Systematic study of iodine nuclei in A?125 mass region  

SciTech Connect (OSTI)

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.

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

449

Tunneling from super- to normal-deformed minima in nuclei.  

SciTech Connect (OSTI)

An excited minimum, or false vacuum, gives rise to a highly elongated superdeformed (SD) nucleus. A brief review of superdeformation is given, with emphasis on the tunneling from the false to the true vacuum, which occurs in the feeding and decay of SD bands. During the feeding process the tunneling is between hot states, while in the decay it is from a cold to a hot state. The {gamma} spectra connecting SD and normal-deformed (ND) states provide information on several physics issues: the decay mechanism; the spin/parity quantum numbers, energies and microscopic structures of SD bands; the origin of identical SD bands; the quenching of pairing with excitation energy; and the chaoticity of excited ND states at 2.5-5 MeV. Other examples of tunneling in nuclei, which are briefly described, include the possible role of tunneling in {Delta}I = 4 bifurcation in SD bands, sub-barrier fusion and proton emitters.

Khoo, T. L.

1998-01-08T23:59:59.000Z

450

Multifragmentation at the balance energy of mass asymmetric colliding nuclei  

E-Print Network [OSTI]

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.

Supriya Goyal

2011-06-20T23:59:59.000Z

451

Relativistic density functional theory for finite nuclei and neutron stars  

E-Print Network [OSTI]

The main goal of the present contribution is a pedagogical introduction to the fascinating world of neutron stars by relying on relativistic density functional theory. Density functional theory provides a powerful--and perhaps unique--framework for the calculation of both the properties of finite nuclei and neutron stars. Given the enormous densities that may be reached in the core of neutron stars, it is essential that such theoretical framework incorporates from the outset the basic principles of Lorentz covariance and special relativity. After a brief historical perspective, we present the necessary details required to compute the equation of state of dense, neutron-rich matter. As the equation of state is all that is needed to compute the structure of neutron stars, we discuss how nuclear physics--particularly certain kind of laboratory experiments--can provide significant constrains on the behavior of neutron-rich matter.

Piekarewicz, J

2015-01-01T23:59:59.000Z

452

Neutrinoless Double Beta Decay in Heavy Deformed Nuclei  

E-Print Network [OSTI]

The zero neutrino mode of the double beta decay in heavy deformed nuclei is investigated in the framework of the pseudo SU(3) model, which has provided an accurate description of collective nuclear structure and predicted half-lives for the two neutrino mode in good agreement with experiments. In the case of $^{238}U$ the calculated zero neutrino half-life is at least three orders of magnitude greater than the two neutrino one, giving strong support of the identification of the radiochemically determined half-life as being the two neutrino double beta decay. For $^{150}Nd$ the zero neutrino matrix elements are of the order of magnitude of, but lesser than, those evaluated using the QRPA. This result confirms that different nuclear models produce similar zero neutrino matrix elements, contrary to the two neutrino case. Using these pseudo SU(3) results and the upper limit for the neutrino mass we estimate the $\\beta\\beta_{0\

Jorge G. Hirsch; O. Castańos; P. O. Hess

1994-07-12T23:59:59.000Z

453

Isovector potential of $?$ in nuclei and neutron star matter  

E-Print Network [OSTI]

We determine the coupling constants of $\\Sigma$ hyperon with mesons in relativistic mean field (RMF) models using $\\Sigma^-$ atomic shift data and examine the effects of $\\Sigma$ on the neutron star maximum mass. We find that we need to reduce the vector-isovector meson coupling with $\\Sigma$ ($g_{\\rho\\Sigma}$) from the value constrained by the SU(3)v symmetry in order to explain the $\\Sigma^-$ atomic shifts for light symmetric and heavy asymmetric nuclei simultaneously. With the atomic shift fit value of $g_{\\rho\\Sigma}$, $\\Sigma^-$ can emerge in neutron star matter overcoming the repulsive isoscalar potential for $\\Sigma$ hyperons. Admixture of $\\Sigma^-$ in neutron stars is found to reduce the neutron star maximum mass slightly.

K. Tsubakihara; A. Ohnishi; T. Harada

2014-02-05T23:59:59.000Z

454

Powerful Outflows and Feedback from Active Galactic Nuclei  

E-Print Network [OSTI]

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.

King, Andrew

2015-01-01T23:59:59.000Z

455

Studies of Relativistic Jets in Active Galactic Nuclei with SKA  

E-Print Network [OSTI]

Relativistic jets in active galactic nuclei (AGN) are among the most powerful astrophysical objects discovered to date. Indeed, jetted AGN studies have been considered a prominent science case for SKA, and were included in several different chapters of the previous SKA Science Book (Carilli & Rawlings 2004). Most of the fundamental questions about the physics of relativistic jets still remain unanswered, and await high-sensitivity radio instruments such as SKA to solve them. These questions will be addressed specially through analysis of the massive data sets arising from the deep, all-sky surveys (both total and polarimetric flux) from SKA1. Wide-field very-long-baseline-interferometric survey observations involving SKA1 will serve as a unique tool for distinguishing between extragalactic relativistic jets and star forming galaxies via brightness temperature measurements. Subsequent SKA1 studies of relativistic jets at different resolutions will allow for unprecedented cosmological studies of AGN jets up...

Agudo, Ivan; Falcke, Heino; Georganopoulos, Markos; Ghisellini, Gabriele; Giovannini, Gabriele; Giroletti, Marcello; Gomez, Jose L; Gurvits, Leonid; Laing, Robert; Lister, Matthew; Marti, Jose-Maria; Meyer, Eileen T; Mizuno, Yosuke; O'Sullivan, Shane; Padovani, Paolo; Paragi, Zsolt; Perucho, Manel; Schleicher, Dominik; Stawarz, Lukasz; Vlahakis, Nektarios; Wardle, John

2015-01-01T23:59:59.000Z

456

Quantum Monte Carlo Calculations of Light Nuclei Using Chiral Potentials  

E-Print Network [OSTI]

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.

J. E. Lynn; J. Carlson; E. Epelbaum; S. Gandolfi; A. Gezerlis; A. Schwenk

2014-11-09T23:59:59.000Z

457

Atomic nuclei decay modes by spontaneous emission of heavy ions  

SciTech Connect (OSTI)

The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (/sup 208/Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 10/sup 10/--10/sup 30/ s: /sup 5/He, /sup 8en-dash10/Be, /sup 11,12/B, /sup 12en-dash16/C, /sup 13en-dash17/N, /sup 15en-dash22/O, /sup 18en-dash23/F, /sup 20en-dash26/Ne, /sup 23en-dash28/Na, /sup 23en-dash30/Mg, /sup 27en-dash32/Al, /sup 28en-dash36/Si, /sup 31en-dash39/P, /sup 32en-dash42/S, /sup 35en-dash45/Cl, /sup 37en-dash47/Ar, /sup 40en-dash49/ K, . .Ca, /sup 44en-dash53/ Sc, /sup 46en-dash53/Ti, /sup 48en-dash54/V, and /sup 49en-dash55/ Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.

Poenaru, D.N.; Ivascu, M.; Sndulescu, A.; Greiner, W.

1985-08-01T23:59:59.000Z

458

Recent results on nuclear structure functions for light nuclei  

SciTech Connect (OSTI)

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 data and HERMES experiments are in a good agreement. We also 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.

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 SC 29208 (United States)

2011-09-21T23:59:59.000Z

459

T invariance and T-odd asymmetries for the cold-polarized-neutron-induced fission of nonoriented nuclei  

SciTech Connect (OSTI)

It is shown that the coefficients D{sup exp} for all T-odd asymmetries observed experimentally in the cross sections for the reactions of cold-polarized-neutron-induced fission of nonoriented target nuclei (which involves the emission of prescission and evaporated particles) comply in shape and scale with the coefficients D{sup theor} calculated for the analogous asymmetries on the basis of quantum-mechanical nuclear-fission theory for T-invariant Hamiltonians of fissile systems. It is also shown that the asymmetries in question arise upon taking into account the effect of (i) the interference between the fission amplitudes of s- and p-wave resonances of a polarized fissile compound nucleus formed in the aforementioned reactions; (ii) the collective rotation of the compound nucleus in question (this rotation entails a change in the angular distributions of fission fragments and third particles); and (iii) the wriggling vibrations of this compound nucleus in the vicinity of its scission point, which lead to the appearance of high aligned spins of fission fragments, with the result that the emission of neutrons and photons evaporated from these fragments becomes anisotropic. The possible contribution of T-noninvariant interactions to the formation of the T-odd asymmetries under analysis is estimated by using the results obtained in experimentally testing the detailed-balance principle, (P-A) theorem, and T invariance of cross sections for elastic proton-proton and proton-neutron scattering.

Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru [Voronezh State University (Russian Federation); Bunakov, V. E. [National Research Center Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation); Titova, L. V. [Voronezh State University (Russian Federation)

2014-12-15T23:59:59.000Z

460

Particle Physics and Cosmology  

E-Print Network [OSTI]

Today, both particle physics and cosmology are described by few parameter Standard Models, i.e. it is possible to deduce consequence of particle physics in cosmology and vice verse. The former is examined in this lecture, in light of the recent systematic exploration of the electroweak scale by the LHC experiments. The two main results of the first phase of the LHC, the discovery of a Higgs-like particle and the absence so far of new particles predicted by "natural" theories beyond the Standard Model (supersymmetry, extra-dimension and composite Higgs) are put in a historical context to enlighten their importance and then presented extensively. To be complete, a short review from the neutrino physics, which can not be probed at LHC, is also given. The ability of all these results to resolve the 3 fundamental questions of cosmology about the nature of dark energy and dark matter as well as the origin of matter-antimatter asymmetry is discussed in each case.

P. Pralavorio

2014-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "nuclei particle counter" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Radiative capture of nucleons at astrophysical energies with single-particle states  

E-Print Network [OSTI]

Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, specially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance, or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region Acapture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.

J. T. Huang; C. A. Bertulani; V. Guimaraes

2009-08-17T23:59:59.000Z

462

Online Particle Size And Concentration Measurement In A Pressurized Coal Combustion Process  

SciTech Connect (OSTI)

The energy industry has to face the demand for highly efficient coal combustion power plants in order to minimize the CO{sub 2} emissions. Efforts are made in new combustion processes, where coal powder is burned at a temperature of 1400 C and a pressure of 16 bars. The hot flue gas is used for a combined gas and steam turbine process. For that reason the flue gas has to be cleaned at the operating temperature and pressure. Limiting values for a secure operation of the turbine, with acceptable abrasion of the blades by impacting particles, are a mass concentration of c{sub M} {le}3 m g/m{sub N}{sup 3} at particle sizes smaller than 3 {micro}m . A granular bed filter is used to remove the gross of fine ash particles. But until now the separation of the submicron aerosol particles at high temperatures does not meet the mentioned specifications, and is still one of the most important open tasks. Regardless what kind of separation process will be implemented to remove fine ash particles, for investigations and control it is necessary to determine the particle concentration and size after the separation. The fact that the particle concentration after the purification is quite small and the size of the particles is less than 10 {micro}m means that gravimetric measurements are not suitable to record spontaneous changes due to the combustion process because of extended sampling times. Additionally a gravimetric measurement technique at operating conditions (T = 1400 C, p = 16 bars) is questionable, because particles can be lost by thermophoretic transport to the walls, also condensation of alkali species on the particle surfaces cannot be avoided (representativity). The single-particle-light-scattering size analysis is especially suited for measurements at low particle concentrations (< 10{sup 5} particles/m{sup 3}). With the counting technique used here, single particles are detected in situ while passing an optically defined measuring volume, which is placed in an iso-kinetically taken sample flow (free working distance of 80 mm and more). The total detectable size range of such a particle counter is between 0,1 and 10 {micro}m. Based on previous successful measurements on the clean gas side of rigid ceramic barrier filters and at a coal combustion pilot plant at temperatures up to 1000 C a constructive solution of this method at high temperatures and pressures is favorable.

Schiel, A.; Umhauer, H.; Kasper, G.; Christmann, W.

2002-09-19T23:59:59.000Z

463

Counter-facing plasma focus system as a repetitive and/or long-pulse high energy density plasma source  

SciTech Connect (OSTI)

A plasma focus system composed of a pair of counter-facing coaxial plasma guns is proposed as a long-pulse and/or repetitive high energy density plasma source. A proof-of-concept experiment demonstrated that with an assist of breakdown and outer electrode connections, current sheets evolved into a configuration for stable plasma confinement at the center of the electrodes. The current sheets could successively compress and confine the high energy density plasma every half period of the discharge current, enabling highly repetitive light emissions in extreme ultraviolet region with time durations in at least ten microseconds.

Aoyama, Yutaka; Nakajima, Mitsuo; Horioka, Kazuhiko [Department of Energy Sciences, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

2009-11-15T23:59:59.000Z

464

Experimental Particle Physics  

SciTech Connect (OSTI)

The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PI's), and C. Rosenfeld (PI), engaged in studies in "Experimental Particle Physics." The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the "flavor" of a neutrino is not immutable. A neutrino of flavor "e," "mu," or "tau," as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they "oscillate." The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a "low energy window" on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the BaBar experiment, which collected data at SLAC until 2008. They continued to analyze the voluminous BaBar data with an emphasis on precision tests of Quantum Chromodynamics and on properties of the "eta_B," a bottom quark paired in a meson with a strange quark. The ATLAS experiment became the principal research focus for Purohit. One of the world's largest pieces of scientific equipment, ATLAS observes particle collisions at the highest-energy particle accelerator ever built, the Large Hadron Collider (LHC) at CERN. Our efforts on ATLAS included participation in the commissioning, calibration, and installation of components called "CSCs". The unprecedented energy of 14 TeV enabled the ATLAS and CMS collaborations to declare discovery of the famous Higgs particle in 2012.

Rosenfeld, Carl [Univ of South Carolina] (ORCID:0000000338571223); Mishra, Sanjib R. [Univ of South Carolina; Petti, Roberto [Univ of South Carolina; Purohit, Milind V. [Univ of South Carolina

2014-08-31T23:59:59.000Z

465

New effects of a long-lived negatively charged massive particle on big bang nucleosynthesis  

SciTech Connect (OSTI)

Primordial {sup 7}Li abundance inferred from observations of metal-poor stars is a factor of about 3 lower than the theoretical value of standard big bang nucleosynthesis (BBN) model. One of the solutions to the Li problem is {sup 7}Be destruction during the BBN epoch caused by a long-lived negatively charged massive particle, X{sup ?}. The particle can bind to nuclei, and X-bound nuclei (X-nuclei) can experience new reactions. The radiative X{sup ?} capture by {sup 7}Be nuclei followed by proton capture of the bound state of {sup 7}Be and X{sup ?} ({sup 7}Be{sub x}) is a possible {sup 7}Be destruction reaction. Since the primordial abundance of {sup 7}Li originates mainly from {sup 7}Li produced via the electron capture of {sup 7}Be after BBN, the {sup 7}Be destruction provides a solution to the {sup 7}Li problem. We suggest a new route of {sup 7}Be{sub x} formation, that is the {sup 7}Be charge exchange at the reaction of {sup 7}Be{sup 3+} ion and X{sup ?}. The formation rate depends on the ionization fraction of {sup 7}Be{sup 3+} ion, the charge exchange cross section of {sup 7}Be{sup 3+}, and the probability that excited states {sup 7}Be{sub x}* produced at the charge exchange are converted to the ground state. We find that this reaction can be equally important as or more important than ordinary radiative recombination of {sup 7}Be and X{sup ?}. The effect of this new route is shown in a nuclear reaction network calculation.

Kusakabe, Motohiko [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791, Korea and Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Kim, K. S. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Cheoun, Myung-Ki [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Kajino, Toshitaka [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kino, Yasushi [Department of Chemistry, Tohoku University, Sendai 980-8578 (Japan); Mathews, Grant J. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

2014-05-02T23:59:59.000Z

466

--Y. 2003. 2[117] Particles and Nuclei, Letters. 2003. No. 2[117] ",,S 539.12...173  

E-Print Network [OSTI]

thick, spanning along the entire X dimension) and one set of spacer plates (small trapezoidal steel is a laminate of steel plates of various dimensions stacked along Z. The basic geometrical element of the stack stack, called module, spans 2/64 in the azimuthal angle (Y dimension), 100 cm in the Z direction and 180

467

Micro-Spectroscopic Imaging and Characterization of Individually Identified Ice Nucleating Particles from a Case Field Study  

SciTech Connect (OSTI)

The effect of anthropogenic and biogenic organic particles on atmospheric glaciation processes is poorly understood. We use an optical microscopy (OM) setup to identify the location of ice nuclei (IN) active in immersion freezing and deposition ice nucleation for temperatures of 200-273 K within a large population of particles sampled from an ambient environment. Applying multi-modal micro-spectroscopy methods we characterize the physicochemical properties of individual IN in particle populations collected in central California. Chemical composition and mixing state analysis of particle populations are performed to identify characteristic particle-type classes. All particle-types contained organic material. Particles in these samples take up water at subsaturated conditions, induce immersion freezing at subsaturated and saturated conditions above 226 K, and act as deposition IN below 226 K. The identified IN belong to the most common particle-type classes observed in the field samples: organic coated sea salt, Na-rich, and secondary and refractory carbonaceous particles. Based on these observations, we suggest that the IN are not always particles with unique chemical composition and exceptional ice nucleation propensity; rather, they are common particles in the ambient particle population. Thus, particle composition and morphology alone are insufficient to assess their potential to act as IN. The results suggest that particle-type abundance is also a crucial factor in determining the ice nucleation efficiency of specific IN types. These findings emphasize that ubiquitous organic particles can induce ice nucleation under atmospherically relevant conditions and that they may play an important role in atmospheric glaciation processes.

Knopf, Daniel A.; Alpert, Peter A.; Wang, Bingbing; O'Brien, Rachel E.; Kelly, Stephen T.; Laskin, Alexander; Gilles, Mary K.; Moffet, Ryan C.

2014-09-03T23:59:59.000Z

468

Beta decay rates for r-process for nuclei near neutron number N=82  

E-Print Network [OSTI]

For r-process nucleosynthesis the beta decay rates of very neutron-rich nuclei are important ingredients. We consider the region around the neutron number N=82 and calculate the half-lives and rates for a number of nuclei. Forms for beta strength functions based on spectral distribution methods are used. The calculated half-lives are first compared to the observed values and then predictions are made for very neutron-rich nuclei close to drip line for which no experimental values are available.

Kamales Kar; Soumya Chakravarti

2008-12-01T23:59:59.000Z

469

Study of nuclei in the vicinity of the "Island of Inversion" through fusion-evaporation reaction  

E-Print Network [OSTI]

We report the first observation of high-spin states in nuclei in the vicinity of the "island of inversion", populated via the 18O+18O fusion reaction at an incident beam energy of 34 MeV. The fusion reaction mechanism circumvents the limitations of non-equilibrated reactions used to populate these nuclei. Detailed spin-parity measurements in these difficult to populate nuclei have been possible from the observed coincidence anisotropy and the linear polarization measurements. The spectroscopy of 33,34P and 33S is presented in detail along with the results of calculations within the shell model framework.

R. Chakrabarti; S. Mukhopadhyay Krishichayan; A. Chakraborty; A. Ghosh; S. Ray; S. S. Ghugre; A. K. Sinha; L. Chaturvedi; A. Y. Deo; I. Mazumdar; P. K. Joshi; R. Palit; Z. Naik; S. Kumar; N. Madhavan; R. P. Singh; S. Muralithar; B. K. Yogi; U. Garg

2009-04-30T23:59:59.000Z

470

Generalized mass formula for non-strange and hyper nuclei with SU(6) symmetry breaking  

E-Print Network [OSTI]

A simultaneous description of non-strange nuclei and hypernuclei is provided by a single mass formula inspired by the spin-flavour SU(6) symmetry breaking. This formula is used to estimate the hyperon binding energies of Lambda, double Lambda, Sigma, Cascade and Theta hypernuclei. The results are found to be in good agreement with the available experimental data on 'bound' nuclei and relativistic as well as quark mean field calculations. This mass formula is useful to estimate binding energies over a wide range of masses including the light mass nuclei. It is not applicable for repulsive potential.

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

2006-01-19T23:59:59.000Z

471

Analysis of the Energy Spectra of Ground States of Deformed Nuclei in rare-earth region  

E-Print Network [OSTI]

The 62Sm, 64Gd, 64Dy, 70Y b, 72Hf and 74W nuclei are classified as deformed nuclei. Low-lying bands are one of the most fundamental excitation modes in the energy spectra of deformed nuclei. In this paper a theoretical analysis of the experimental data within the phenomenological model is presented. The energy spectra of ground states are calculated. It is found the low-lying spectra of ground band states are in good agreement with the experimental data.

Abdurahim A. Okhunov; G. I. Turaeva; M. U. Khandaker; Noora B. Rosli

2014-05-28T23:59:59.000Z

472

Integral charged particle nuclear date bibliography. Editon 1, Supplement 2  

SciTech Connect (OSTI)

This bibliography is divided into three sections, ''References'', ''Target Index'', and ''Residual Index.'' The ''References'' section contains all references satisfying the following criteria: excitation functions, thick targets, or product yield leading to the formation of a ground or metastable state; the atomic mass and charge of the incident particle must be greater than or equal to 1; the atomic mass of the target must be greater than or equal to 1; and the atomic masses of the outgoing and residual nuclei must be greater than or equal to 1 with the exception of processes which do not lead to a definite residual nucleus and of gamma-ray production cross sections. The ''Target Index'' section contains the incident particle energy and the abbreviated reference lines for all the entries, which contain information on a definite target nucleus and reaction. These reference lines contain the Journal name, followed by the volume and page number. The ''Residual Index'' section also contains the incident particle energy and the abbreviated reference lines for all the entries, which contain information on a definite residual nucleus and a definite target-reaction.

Holden, N.E.; Ramavataram, S.; Dunford, C.L.

1986-04-01T23:59:59.000Z

473

Masses of Fundamental Particles  

E-Print Network [OSTI]

In the original paper entitled, "Masses of Fundamental Particles"(arXiv:1109.3705v5, 10 Feb 2012), not only the masses of fundamental particles including the weak bosons, Higgs boson, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite models of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

Hidezumi Terazawa

2014-06-11T23:59:59.000Z

474

Particle detector spatial resolution  

DOE Patents [OSTI]

Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution is disclosed. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector. 12 figs.

Perez-Mendez, V.

1992-12-15T23:59:59.000Z

475

Particle detector spatial resolution  

DOE Patents [OSTI]

Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector.

Perez-Mendez, Victor (Berkeley, CA)

1992-01-01T23:59:59.000Z

476

Dynamic radioactive particle source  

DOE Patents [OSTI]

A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

2012-06-26T23:59:59.000Z

477

ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI  

SciTech Connect (OSTI)

We present the properties of the ensemble variability V for nearly 5000 near-infrared active galactic nuclei (AGNs) selected from the catalog of Quasars and Active Galactic Nuclei (13th Edition) and the SDSS-DR7 quasar catalog. From three near-infrared point source catalogs, namely, Two Micron All Sky Survey (2MASS), Deep Near Infrared Survey (DENIS), and UKIDSS/LAS catalogs, we extract 2MASS-DENIS and 2MASS-UKIDSS counterparts for cataloged AGNs by cross-identification between catalogs. We further select variable AGNs based on an optimal criterion for selecting the variable sources. The sample objects are divided into subsets according to whether near-infrared light originates by optical emission or by near-infrared emission in the rest frame; and we examine the correlations of the ensemble variability with the rest-frame wavelength, redshift, luminosity, and rest-frame time lag. In addition, we also examine the correlations of variability amplitude with optical variability, radio intensity, and radio-to-optical flux ratio. The rest-frame optical variability of our samples shows negative correlations with luminosity and positive correlations with rest-frame time lag (i.e., the structure function, SF), and this result is consistent with previous analyses. However, no well-known negative correlation exists between the rest-frame wavelength and optical variability. This inconsistency might be due to a biased sampling of high-redshift AGNs. Near-infrared variability in the rest frame is anticorrelated with the rest-frame wavelength, which is consistent with previous suggestions. However, correlations of near-infrared variability with luminosity and rest-frame time lag are the opposite of these correlations of the optical variability; that is, the near-infrared variability is positively correlated with luminosity but negatively correlated with the rest-frame time lag. Because these trends are qualitatively consistent with the properties of radio-loud quasars reported by some previous studies, most of our sample objects are probably radio-loud quasars. Finally, we also discuss the negative correlations seen in the near-infrared SFs.

Kouzuma, S. [School of International Liberal Studies, Chukyo University, Toyota 470-0393 (Japan); Yamaoka, H., E-mail: skouzuma@lets.chukyo-u.ac.jp, E-mail: yamaoka@phys.kyushu-u.ac.jp [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)

2012-03-01T23:59:59.000Z

478

Cosmology with decaying particles  

SciTech Connect (OSTI)

We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.

Turner, M.S.

1984-09-01T23:59:59.000Z

479

Alpha Particle Diagnostic  

SciTech Connect (OSTI)

The study of burning plasmas is the next frontier in fusion energy research, and will be a major objective of the U.S. fusion program through U.S. collaboration with our international partners on the ITER Project. For DT magnetic fusion to be useful for energy production, it is essential that the energetic alpha particles produced by the fusion reactions be confined long enough to deposit a significant fraction of their initial ~3.5 MeV energy in the plasma before they are lost. Development of diagnostics to study the behavior of energetic confined alpha particles is a very important if not essential part of burning plasma research. Despite the clear need for these measurements, development of diagnostics to study confined the fast confined alphas to date has proven extremely difficult, and the available techniques remain for the most part unproven and with significant uncertainties. Research under this grant had the goal of developing diagnostics of fast confined alphas, primarily based on measurements of the neutron and ion tails resulting from alpha particle knock-on collisions with the plasma deuterium and tritium fuel ions. One of the strengths of this approach is the ability to measure the alphas in the hot plasma core where the interesting ignition physics will occur.

Fisher, Ray, K.

2009-05-13T23:59:59.000Z

480

Particle-free microchip processing  

DOE Patents [OSTI]

Method and apparatus for reducing particulate contamination in microchip processing are disclosed. The method and apparatus comprise means to reduce particle velocity toward the wafer before the particles can be deposited on the wafer surface. A reactor using electric fields to reduce particle velocity and prevent particulate contamination is disclosed. A reactor using a porous showerhead to reduce particle velocities and prevent particulate contamination is disclosed. 5 figs.

Geller, A.S.; Rader, D.J.

1996-06-04T23:59:59.000Z