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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

Optical Airborne Particle Counter Operation  

Science Journals Connector (OSTI)

For most cleanroom airborne particle measurements, an optical single particle ... or surrogates of the product or of the cleanroom environment. The last procedure is used to...

Alvin Lieberman

1992-01-01T23:59:59.000Z

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

Active Galactic Nuclei Shed Light on Axionlike Particles  

Science Journals Connector (OSTI)

We demonstrate that the scatter in the luminosity relations of astrophysical objects can be used to search for axionlike particles. This analysis is applied to observations of active galactic nuclei, where we find evidence highly suggestive of the existence of a very light axionlike particle.

Clare Burrage; Anne-Christine Davis; Douglas J. Shaw

2009-05-21T23:59:59.000Z

6

Alpha particle cluster states in fp-shell nuclei  

Science Journals Connector (OSTI)

Alpha particle cluster structure is known experimentally to persist throughout the mass range 16?A?20, and has been very successfully described in this region in terms of the Buck-Dover-Vary local potential cluster model. It is argued that an analogous cluster structure should be present in nuclei at the beginning of the fp shell, and the available experimental data are examined to determine likely alpha particle cluster state candidates in the mass range 40?A?44. Calculations of the cluster state spectra and mean square cluster-core separation distances (which may be readily used to evaluate E2 electromagnetic transition rates) for Ca40, Ca42, Sc42, Sc43, Ti43, and Ti44 using the above-mentioned model are presented, and compared with experimental measurements where possible. The agreement between theory and experiment is generally good (although inferior to that obtained in the sd shell), and points to the desirability of an extension and improvement of the measurements of the properties of the excited states in these nuclei.

A. C. Merchant

1987-08-01T23:59:59.000Z

7

Ice Nuclei in Marine Air: Biogenic Particles or Dust?  

SciTech Connect

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

8

Particles and nuclei, letters, in Russian, pt.3  

E-Print Network (OSTI)

The present collection of letters from JINR, Dubna, contains eight separate records on the role of the complanar emission of particles in nuclear interaction for E sub 0 >10 sup 1 sup 6 eV detected in the stratosphere, sup 1 sup 0 B nucleus fragment yields, nuclear teleportation (proposal for an experiment), invisible 'glue' bosons in model field theory, calculation of the ionization differential effective cross sections in fast ion-atom collisions, interactions of ultracold neutrons near surface of solids, g factors as a probe for high-spin structure of neutron-rich Dy isotopes, search for periodicities in experimental data by the autoregressive model methods

2002-01-01T23:59:59.000Z

9

ARM - Measurement - Cloud condensation nuclei  

NLE Websites -- All DOE Office Websites (Extended Search)

condensation nuclei condensation nuclei ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud condensation nuclei Small particles (typically 0.0002 mm, or 1/100 th the size of a cloud droplet) about which cloud droplets coalesce. Categories Aerosols, Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CCN : Cloud Condensation Nuclei Particle Counter Field Campaign Instruments AOS : Aerosol Observing System

10

Dynamics of nuclear single-particle structure in covariant theory of particle-vibration coupling: From light to superheavy nuclei  

SciTech Connect

The impact of particle-vibration coupling and polarization effects due to deformation and time-odd mean fields on single-particle spectra is studied systematically in doubly magic nuclei from low-mass {sup 56}Ni up to superheavy ones. Particle-vibration coupling is treated fully self-consistently within the framework of the relativistic particle-vibration coupling model. Polarization effects due to deformation and time-odd mean field induced by odd particle are computed within covariant density functional theory. It has been found that among these contributions the coupling to vibrations makes a major impact on the single-particle structure. The impact of particle-vibration coupling and polarization effects on calculated single-particle spectra, the size of the shell gaps, the spin-orbit splittings and the energy splittings in pseudospin doublets is discussed in detail; these physical observables are compared with experiment. Particle-vibration coupling has to be taken into account when model calculations are compared with experiment since this coupling is responsible for observed fragmentation of experimental levels; experimental spectroscopic factors are reasonably well described in model calculations.

Litvinova, E. V.; Afanasjev, A. V. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt, Germany and Institut fuer Theoretische Physik, Goethe-Universitaet, D-60438 Frankfurt am Main (Germany); Department of Physics and Astronomy, Mississippi State University, Mississippi 39762 (United States)

2011-07-15T23:59:59.000Z

11

Charge-changing particle-hole excitation of {sup 16}N and {sup 16}F nuclei  

SciTech Connect

The nuclear structure of {sup 16}N (closed shell + ? ? ?) and {sup 16}F (closed shell + ? ? ?) nuclei is studied using particle-hole proton-neutron Tamm-Dancoff Approximation pn TDA and particle-hole proton-neutron Random Phase Approximation pn RPA. The particle-hole Hamiltonian of PSD model space is to be diagonalized in the presence of the PSDMWKPN interaction: for P-space the Cohen-Kurath interaction, for SD-space the Wildenthal Interaction, for the coupling matrix elements between P- and SD-spaces the Millener-Kurath interaction is used, spurious components were eliminated with CM contribution. The results containing energy level schemes and electromagnetic transition strength are compared with the available experimental data.

Taqi Al-Bayati, Ali H.; Darwesh, Sarah S. [Physics Department, College of Science, Kirkuk University, Kirkuk (Iraq)

2013-12-16T23:59:59.000Z

12

Spectroscopy of few-particle nuclei around magic {sup 132}Sn from fission product {gamma}-ray studies.  

SciTech Connect

We are studying the yrast structure of very neutron-rich nuclei around doubly magic {sup 132}Sn by analyzing fission product {gamma}-ray data from a {sup 248}Cm source at Eurogam II. Yrast cascades in several few-valence-particle nuclei have been identified through {gamma}{gamma} cross coincidences with their complementary fission partners. Results for two-valence-particle nuclei {sup 132}Sb, {sup 134}Te, {sup 134}Sb and {sup 134}Sn provide empirical nucleon-nucleon interactions which, combined with single-particle energies already known in the one-particle nuclei, are essential for shell-model analysis in this region. Findings for the N = 82 nuclei {sup 134}Te and {sup 135}I have now been extended to the four-proton nucleus {sup 136}Xe. Results for the two-neutron nucleus {sup 134}Sn and the N = 83 isotones {sup 134}Sb, {sup 135}Te and {sup 135}I open up the spectroscopy of nuclei in the northeast quadrant above {sup 132}Sn.

Zhang, C. T.

1998-07-29T23:59:59.000Z

13

Ab initio Approach to Effective Single-Particle Energies in Doubly Closed Shell Nuclei  

SciTech Connect

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 of extracting ESPEs through the diagonalization of the centroid matrix, as originally argued by Baranger. For the purpose of illustration, we analyze the impact of correlations on observable one-nucleon separation energies and nonobservable ESPEs in selected closed-shell oxygen and calcium isotopes. We then state and illustrate the nonobservability 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 of employing consistent structure and reaction models based on the same nuclear Hamiltonian to extract the shell structure in a meaningful fashion from experimental data.

Duguet, T. [CEA-Saclay DSM/Irfu/SPhN, France/NSCL, Michigan State University; Hagen, G. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)

2012-01-01T23:59:59.000Z

14

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

15

Formation of viable nuclei and particle growth in hydrothermal processing of silicon dioxide wafers: A modeling study of entrance effects  

SciTech Connect

A major problem that besets rapid hydrothermal processing of silicon dioxide wafers is the formation of particles. In this report we have used The Becker, Doering, Zeldovich theory of homogeneous condensation of viable nuclei to study particle formation in a hydrothermal processing chamber. We have further utilized a diffusive growth model that allows these nuclei to develop into larger particles. In addition, we have developed a model to partially dissolve the walls of the quartz chamber into the steam flowing by. The interplay between homogeneous nucleation and inhomogeneous nucleation is brought out via a dimensionless number that is the ratio of the timescales of these two phenomena. An analytic model was developed to prove in consonance with numerical results that unless the incoming stream is itself supersaturated, there will be no nucleation near the entrance.

Chitanvis, S.M.

1994-08-01T23:59:59.000Z

16

Deformation effects on the coexistence between neutron-proton and particle like pairing in N=Z medium mass nuclei  

E-Print Network (OSTI)

A model combining self-consistent mean-field and shell-model techniques is used to study the competition between particle like and proton-neutron pairing correlations in fp-shell even-even self-conjugate nuclei. Results obtained using constant two-body pairing interactions as well as more sophisticated interactions are presented and discussed. The standard BCS calculations are systematically compared with more refined approaches including correlation effects beyond the independent quasi-particle approach. The competition between proton-neutron correlations in the isoscalar and isovector channels is also analyzed, as well as their dependence on the deformation properties. Besides the expected role of the spin-orbit interaction and particle number conservation, it is shown that deformation leads to a reduction of the pairing correlations. This reduction originates from the change of the single-particle spectrum and from a quenching of the residual pairing matrix elements. The competition between isoscalar and i...

Gambacurta, D

2014-01-01T23:59:59.000Z

17

COUNTERING TERRORISM  

Science Journals Connector (OSTI)

COUNTERING TERRORISM ... In "Protecting the American Homeland: A Preliminary Analysis," the scholars propose a fourtiered homeland security program that would secure U.S. borders, prevent terrorist attacks, protect key domestic sites, and manage the consequences of an attack if the other measures fail. ... But plant products could also be stolen and used by terrorists to attack other targets. ...

LOIS EMBER

2002-05-06T23:59:59.000Z

18

Detection of internally mixed Asian dust with air pollution aerosols using a polarization optical particle counter and a polarization-sensitive two-wavelength lidar  

Science Journals Connector (OSTI)

Abstract East Asia is a unique region where mineral dust (Asian dust) sources are located near urban and industrial areas. Asian dust is often mixed with air pollution aerosols during transportation. It is important to understand the mixing states of Asian dust and other aerosols, because the effects on the environment and human health differ depending on the mixing state. We studied the mixing states of Asian dust using a polarization particle counter (POPC) that measures the forward scattering and the two polarization components of backscattering for single particles and a polarization-sensitive (532 nm) two-wavelength (1064 nm and 532 nm) lidar. We conducted the simultaneous observations using the POPC and the lidar in Seoul from March to December 2013 and captured the characteristics of pure Asian dust and internally mixed polluted Asian dust. POPC measurements indicated that the density of large particles was lower in polluted Asian dust that transported slowly over the polluted areas than in pure Asian dust that transported quickly from the dust source region. Moreover, the backscattering depolarization ratio was smaller for all particle sizes in polluted dust. The optical characteristics measured using the lidar were consistent with the POPC measurements. The backscattering color ratio of polluted dust was comparable to that of pure dust, but the depolarization ratio was lower for polluted dust. In addition, coarse non-spherical particles (Asian dust) almost always existed in the background, and the depolarization ratio had seasonal variation with a lower depolarization ratio in the summer. These results suggest background Asian dust particles are internally mixed in the summer.

Nobuo Sugimoto; Tomoaki Nishizawa; Atsushi Shimizu; Ichiro Matsui; Hiroshi Kobayashi

2015-01-01T23:59:59.000Z

19

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

20

Superdeformed nuclei  

SciTech Connect

This paper reviews the most recent advances in the understanding of the physics of superdeformed nuclei from the point of view of the experimentalists. It covers among other subjects the following topics: (1) the discovery of a new region of superdeformed nuclei near A=190, (2) the surprising result of the occurrence of bands with identical transition energies in neighboring superdeformed nuclei near A=150 and A=190, (3) the importance of octupole degrees of freedom at large deformation and (4) the properties associated with the feeding and the decay of superdeformed bands. The text presented hereafter will appear as a contribution to the Annual Review of Nuclear and Particle Science, Volume 41. 88 refs., 11 figs.

Janssens, R.V.F.; Khoo, Teng Lek.

1991-01-01T23:59:59.000Z

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.


21

Continuum particle-vibration coupling method in coordinate-space representation for finite nuclei  

E-Print Network (OSTI)

In this paper we present a new formalism to implement the nuclear particle-vibration coupling (PVC) model. The key issue is the proper treatment of the continuum, that is allowed by the coordinate space representation. Our formalism, based on the use of zero-range interactions like the Skyrme forces, is microscopic and fully self-consistent. We apply it to the case of neutron single-particle states in $^{40}$Ca, $^{208}$Pb and $^{24}$O. The first two cases are meant to illustrate the comparison with the usual (i.e., discrete) PVC model. However, we stress that the present approach allows to calculate properly the effect of PVC on resonant states. We compare our results with those from experiments in which the particle transfer in the continuum region has been attempted. The latter case, namely $^{24}$O, is chosen as an example of a weakly-bound system. Such a nucleus, being double-magic and not displaying collective low-lying vibrational excitations, is characterized by quite pure neutron single-particle states around the Fermi surface.

Kazuhito Mizuyama; Gianluca Colò; Enrico Vigezzi

2012-05-04T23:59:59.000Z

22

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

23

Nuclear reactions of medium and heavy target nuclei with high-energy particles IV. Interpretation of mass fragment yields  

Science Journals Connector (OSTI)

Target residue mass distributions in 3·65 A GeV12C-ion- and 3·65 GeV proton-induced reactions on medium and heavy target nuclei have been interpreted in the theoretical framework of the intranuclear cascade and a...

P. Kozma; K. Hänssgen

1990-06-01T23:59:59.000Z

24

Pyrochemical multiplicity counter development  

SciTech Connect

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

25

EMSL - nuclei  

NLE Websites -- All DOE Office Websites (Extended Search)

nuclei en Diffusional Motion of Redox Centers in Carbonate Electrolytes . http:www.emsl.pnl.govemslwebpublicationsdiffusional-motion-redox-centers-carbonate-electrolytes

26

Counter Current Multiplier Mechanism  

NLE Websites -- All DOE Office Websites (Extended Search)

Counter Current Multiplier Mechanism Counter Current Multiplier Mechanism Name: Stephen Location: N/A Country: N/A Date: N/A Question: Can you please explain to me the counter-current multiplier mechanism. I understand that cholride and sodium ions are filtered out of the ascending loop of Henle into the interstial fluid, however, I'm not sure exactly what happens from there and how this effects osmotic pressure gradients in the nephron. Any help would be greatly appriciated. Replies: This mechanism is very complex when it comes to writing a response. You have to have a strong background in osmotic pressure understanding and the anatomy of the kidney. It involves the cortex, outer and inner medula in relationship to the vasa recta, interstitial fluids at two points, the loop of Henle and the collecting duct. The size of the tubes and the position in relations to the cortex and medulla is an essential part. I can suggest some references.

27

Compressor surge counter  

DOE Patents (OSTI)

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

Castleberry, Kimberly N. (Harriman, TN)

1983-01-01T23:59:59.000Z

28

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.

29

Detection of Neutrons with Scintillation Counters  

DOE R&D Accomplishments (OSTI)

Detection of slow neutrons by: detection of single gamma rays following capture by cadmium or mercury; detection of more than one gamma ray by observing coincidences after capture; detection of heavy charged particles after capture in lithium or baron nuclei; possible use of anthracene for counting fast neutrons investigated briefly.

Hofstadter, R.

1948-11-01T23:59:59.000Z

30

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

31

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.

32

COUNTERING MICROBIAL THREATS  

Science Journals Connector (OSTI)

COUNTERING MICROBIAL THREATS ... The highly contagious disease dubbed severe acute respiratory syndrome, first seen in Asia but now diagnosed in several other countries, underscores the report's key point: More must be done to improve the public health and medical communities' ability to prevent, detect, and control emerging and resurging health threats posed by wily microbes. ... Because we all live on the same global microbial real estate, "one nation's problem soon can become every nation's problem," warns Margaret A. Hamburg, cochair of the panel that produced the report, "Microbial Threats to Health: Emergence, Detection & Response." ...

LOIS EMBER

2003-03-24T23:59:59.000Z

33

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

34

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

35

Alternatives for Helium-3 in Multiplicity Counters  

SciTech Connect

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

36

Discharge quencher for Geiger counters  

SciTech Connect

A discharge quencher for halogen Geiger counters with a total powercutoff time after the appearance of an input signal of -70 nsec and an input sensitivity of -50 mV is described. The circuit permits parallel control of five STS-5 counters for a quenching-pulse duration of 4.5 usec. Counting responses with slopes to 0.131%/V and a plateau width of 100 V at a load of 60,000 pulses/sec are obtained for two STS-5 counters. The maximum load is 120,000 pulses/sec.

Mushev, R.K.

1986-03-01T23:59:59.000Z

37

Structure and spectroscopy of transcurium nuclei.  

SciTech Connect

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

38

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

39

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

40

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

DOE Patents (OSTI)

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

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

2001-01-01T23:59:59.000Z

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

Apparatus Drawings Project. Report Number 22. Proportional Counter  

Science Journals Connector (OSTI)

A cylindrical cathode-coaxial anodeproportional counter designed for an undergraduate laboratory is described. A collimated beam of ? particles can be directed into the counter at any point along a narrow longitudinal window in the cathode wall and used to examine the electric field surrounding the anode structure at any point along its length. The anode wire has an enlarged section at one end and is surrounded at the other by an independently biased coaxial auxiliary electrode. The effectiveness of these two geometrical methods for controlling the production of secondary ionization can be studied as can the effects of varying gas composition pressure and operating voltage. A variable output-2000-v power supply pulse amplifying and counting equipment a cathode ray oscilloscope and a small mechanical vacuum pump are also needed for these experiments. Detailed information on construction of the counter and gas handling system is given.

Robert G. Marcley

1962-01-01T23:59:59.000Z

42

Countering Nuclear Terrorism | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

Countering Nuclear Terrorism | National Nuclear Security Administration Countering Nuclear Terrorism | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog The National Nuclear Security Administration Countering Nuclear Terrorism Home > Our Mission > Countering Nuclear Terrorism Countering Nuclear Terrorism NNSA provides expertise, practical tools, and technically informed policy

43

Separating Cloud Forming Nuclei from Interstitial Aerosol  

SciTech Connect

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

44

Basic Research Needs for Countering Terrorism  

SciTech Connect

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

45

Countering Nuclear Terrorism and Trafficking | National Nuclear...  

National Nuclear Security Administration (NNSA)

Countering Nuclear Terrorism and Trafficking | National Nuclear Security Administration People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy...

46

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

47

Boron-10 Lined Proportional Counter Wall Effects  

SciTech Connect

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

48

Nucleons, Nuclei, and Atoms 1.1 Overview  

E-Print Network (OSTI)

1 Nucleons, Nuclei, and Atoms 1.1 Overview Despite the success of the Standard Model in explaining is the theme of this chapter: ultrasensitive techniques in atomic, nuclear, and particle physics that might of fundamental symmetries in experiments involving nucleons, nuclei, and atoms have played an essential role

49

High Energy Solar Particles  

Science Journals Connector (OSTI)

6 May 1976 research-article High Energy Solar Particles J. J. Quenby Protons, heavy nuclei and electrons are seen to be emitted from solar flares with energies extending up to the relativistic region. Three different...

1976-01-01T23:59:59.000Z

50

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

51

EMSL - quadrupolar nuclei  

NLE Websites -- All DOE Office Websites (Extended Search)

quadrupolar-nuclei en Diffusional Motion of Redox Centers in Carbonate Electrolytes . http:www.emsl.pnl.govemslwebpublicationsdiffusional-motion-redox-centers-carbonate-electr...

52

Nuclear Shell Structure and Beta Decay I. Odd A Nuclei II. Even A Nuclei  

DOE R&D Accomplishments (OSTI)

In Part I a systematics is given of all transitions for odd A nuclei for which sufficiently reliable data are available. The allowed or forbidden characters of the transitions are correlated with the positions of the initial and final odd nucleon groups in the nuclear shell scheme. The nuclear shells show definite characteristics with respect to parity of the ground states. The latter is the same as the one obtained from known spins and magnetic moments in a one-particle interpretation. In Part II a systematics of the beta transitions of even-A nuclei is given. An interpretation of the character of the transitions in terms of nuclear shell structure is achieved on the hypothesis that the odd nucleon groups have the same structure as in odd-A nuclei, together with a simple coupling rule between the neutron and proton groups in odd-odd nuclei.

Mayer, M.G.; Moszkowski, S.A.; Nordheim, L.W.

1951-05-00T23:59:59.000Z

53

BG/Q Performance Counters | Argonne Leadership Computing Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

supports a large set of hardware performance counters accessible through the native BGPM API. Detailed documentation on the performance counter hardware and BGPM API is available...

54

Taming Past LTL and Flat Counter Systems  

E-Print Network (OSTI)

Reachability and LTL model-checking problems for flat counter systems are known to be decidable but whereas the reachability problem can be shown in NP, the best known complexity upper bound for the latter problem is made of a tower of several exponentials. Herein, we show that the problem is only NP-complete even if LTL admits past-time operators and arithmetical constraints on counters. Actually, the NP upper bound is shown by adequately combining a new stuttering theorem for Past LTL and the property of small integer solutions for quantifier-free Presburger formulae. Other complexity results are proved, for instance for restricted classes of flat counter systems.

Demri, Stéphane; sangnier, Arnaud

2012-01-01T23:59:59.000Z

55

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

56

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

SciTech Connect

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

57

Optical Particle Counter Operating Procedures, Calibration and Correlation Methods  

Science Journals Connector (OSTI)

Data from any OPC are derived on the basis of a number of OPC design and operating parameters. Most operators assume that the data produced are valid for any material and under any circumstances. However, it must...

Alvin Lieberman

1992-01-01T23:59:59.000Z

58

?erenkov Counter Flux Measurement of Cosmic-Ray Alphas at 41°  

Science Journals Connector (OSTI)

A ?erenkov counter inside a Geiger counter telescope was flown by balloon to a residual atmospheric depth of 16 g/cm2. The purpose of the experiment was to measure the flux of cosmic-ray alpha particles and to investigate the usefulness of a ?erenkov counter for flux measurements on the more heavily charged cosmicray components. A ?erenkov counter was used because of its inherent discrimination against slow secondary particles. The pulse height distribution obtained showed a partially resolved peak at approximately 4 h0, where h0 is the mean pulse height corresponding to a fast proton. This is experimental confirmation of the Z2 dependence for ?erenkov radiation. There were 3024 events which gave pulse heights corresponding to alphas. There is evidence that 451 were due to side showers, 651 were due to nuclear interactions, an additional 478 were due to either side showers or interactions, and 1444 were due to primary alphas. This leads to the value 99±16 particles/m2-steradian-second, as the extrapolated flux at the top of the atmosphere. There is also an indication of peaks corresponding to carbon and oxygen. There is evidence that the geometry factor of the telescope was appreciably increased for the heavy components due to the action of delta rays.

Nahmin Horwitz

1955-04-01T23:59:59.000Z

59

Symmetries in nuclei  

SciTech Connect

The use of dynamical symmetries or spectrum generating algebras for the solution of the nuclear many-body problem is reviewed. General notions of symmetry and dynamical symmetry in quantum mechanics are introduced and illustrated with simple examples such as the SO(4) symmetry of the hydrogen atom and the isospin symmetry in nuclei. Two nuclear models, the shell model and the interacting boson model, are reviewed with particular emphasis on their use of group-theoretical techniques.

Van Isacker, P. [Grand Accelerateur National d'Ions Lourds, CEA/DSM-CNRS/IN2P3 BP 55027, F-14076 Caen Cedex 5 (France)

2011-03-21T23:59:59.000Z

60

///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

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

Modelling boron-lined proportional counter response to neutrons  

Science Journals Connector (OSTI)

......of lithium. BF3 and boron-lined proportional...counters that employ 10B isotopes, the first in the gaseous...might be expected that boron-lined counters would...function of a typical boron-lined counter (2013...Koohi-Fayegh R. Determination of 4.43 MeV gamma-ray......

A. Shahri; N. Ghal-Eh; G. R. Etaati

2013-09-01T23:59:59.000Z

62

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

63

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

2006-01-11T23:59:59.000Z

64

Report on intercomparisons of condensation nucleus counter measurements during the ACE-1 intensive study  

SciTech Connect

This report summarizes findings from intercomparisons of aerosol particle concentrations measured by condensation nucleus counters (CNC`s) on various platforms and ground-based stations during the Southern Hemisphere Marine Aerosol Characterization Experiment (ACE-1). Five CNC`s on the NCAR C-130 are intercompared. The C-130 CNC`s are then intercompared to ship ground-based measurements during periods of C-130 overflights.

Weber, R.J.

1997-06-01T23:59:59.000Z

65

Medium-Heavy Nuclei from Nucleon-Nucleon Interactions in Lattice QCD  

E-Print Network (OSTI)

On the basis of the Brueckner-Hartree-Fock method with the nucleon-nucleon forces obtained from lattice QCD simulations, the properties of the medium-heavy doubly-magic nuclei such as 16^O and 40^Ca are investigated. We found that those nuclei are bound for the pseudo-scalar meson mass M_PS ~ 470 MeV. The mass number dependence of the binding energies, single-particle spectra and density distributions are qualitatively consistent with those expected from empirical data at the physical point, although these hypothetical nuclei at heavy quark mass have smaller binding energies than the real nuclei.

Inoue, Takashi; Charron, Bruno; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji

2014-01-01T23:59:59.000Z

66

Medium-Heavy Nuclei from Nucleon-Nucleon Interactions in Lattice QCD  

E-Print Network (OSTI)

On the basis of the Brueckner-Hartree-Fock method with the nucleon-nucleon forces obtained from lattice QCD simulations, the properties of the medium-heavy doubly-magic nuclei such as 16^O and 40^Ca are investigated. We found that those nuclei are bound for the pseudo-scalar meson mass M_PS ~ 470 MeV. The mass number dependence of the binding energies, single-particle spectra and density distributions are qualitatively consistent with those expected from empirical data at the physical point, although these hypothetical nuclei at heavy quark mass have smaller binding energies than the real nuclei.

Takashi Inoue; Sinya Aoki; Bruno Charron; Takumi Doi; Tetsuo Hatsuda; Yoichi Ikeda; Noriyoshi Ishii; Keiko Murano; Hidekatsu Nemura; Kenji Sasaki

2014-08-21T23:59:59.000Z

67

Boron-10 Lined Proportional Counter Model Validation  

SciTech Connect

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

68

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

69

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

70

A water-based neutron detector as a well multiplicity counter  

Science Journals Connector (OSTI)

Abstract We report the performance characteristics of a water-based neutron detecting multiplicity counter for the non-destructive assay of fissile sources. This technique could replace or supplement existing 3He-based multiplicity counters. The counter is a 1.02 m3 tank containing pure deionized water doped with 0.5% GdCl3. It has highly reflective walls and eight 10-in. \\{PMTs\\} mounted at the top. An unshielded source well of 19 cm diameter, mounted at the top and center, extends 73 cm down into the detector. The counter was evaluated using low intensity 252Cf and 60Co sources, and a fast pulsing LED to simulate higher intensity backgrounds. At low gamma ray intensities (~200 kBq or less) we report an absolute neutron detection efficiency of 28% and a 60Co rejection/suppression factor of ~108 to 1. For sources with high gamma ray intensities, the neutron efficiency was 22%±1% up to a 60Co equivalent activity of 4 MBq. The detector background event rate, primarily due to muons and other cosmogenic particles, was found to be stable over a period of almost three months. The minimum detectable neutron source intensity above background was 3.1 n/s, assuming a one-hour data acquisition.

S. Dazeley; A. Asghari; A. Bernstein; N.S. Bowden; V. Mozin

2015-01-01T23:59:59.000Z

71

Observable consequences of Langmuir turbulence in active galactic nuclei  

SciTech Connect

The authors discuss in detail the observable consequences of non-linear microscopic plasma processes in active galactic nuclei. The combination of several elementary momentum gain (shock acceleration and stochastic acceleration) and loss processes (synchroton radiation, inverse Compton scattering) produces an almost monoenergetic distribution function of relativistic electrons - the pile-up - which excites Langmuir waves. Turbulent wave-wave and wave-particle interactions lead to nonlinear stabilization of the pile-up. The temporal and spatial evolution of the Langmuir waves and the relativistic electrons determine the shape and time scale of the spectral variations. The model is applied to extragalactic nuclei and to the galactic center as well.

Lesch, H.

1989-04-01T23:59:59.000Z

72

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

73

ARM - Field Campaign - MASRAD: Cloud Condensate Nuclei Chemistry  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsMASRAD: Cloud Condensate Nuclei Chemistry Measurements govCampaignsMASRAD: Cloud Condensate Nuclei Chemistry Measurements Campaign Links AMF Point Reyes Website Related Campaigns MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14, Miller, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01 - 2005.07.30 Lead Scientist : Carl Berkowitz For data sets, see below. Description Principal Investigators: J. Ogren, C. Berkowitz, R. Halthore, A. Laskin, A. Strawa, J. Wang, A. Wexler As part of the ARM Mobile Facility (AMF) deployment to Point Reyes, CA in the spring and summer of 2005, a suite of instrumentation was installed to measure the chemical, physical and optical properties of aerosol particles

74

Neutron skin of nuclei near the neutron drip line  

Science Journals Connector (OSTI)

Performing Skyrme-type deformed Hartree-Fock calculations, the possible presence of neutron skin in nuclei towards neutron drip line is studied. The thickness of the neutron skin is found to be nearly constant in all directions if it is measured perpendicular to the surface, and in a given nucleus the number of neutrons being inside of the neutron skin is almost independent of the deformation (namely, spherical shape or normal deformation or superdeformation). In the region of medium-heavy nuclei our calculation shows the presence of a series of neutron-rich nuclei, in which a neutron skin is present and yet the neutron one-particle spectra are far from those in a harmonic oscillator (plus spin-orbit) potential.

I. Hamamoto and X. Z. Zhang

1995-11-01T23:59:59.000Z

75

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

76

Rotational Motion in Nuclei  

Science Journals Connector (OSTI)

...and single-particle motion, but the basic idea of the cranking model has stood its...the schematized SU3 picture. General Theory of Rotation The increasing precision and...pro-vided by the challenge of presenting the theory of rotation as part of a broad view of...

Aage Bohr

1976-07-16T23:59:59.000Z

77

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

SciTech Connect

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

78

Isomer Tagging with a Dual Multi-Wire Proportional Counter and a Differential Plunger  

SciTech Connect

This report details the status of an experimental research programme which has studied isomeric states in the mass 130-160 region of the nuclear chart. Several new isomers have been established and characterised near the proton drip line using a recoil isomer tagging technique at the University of Jyvaeskylae, Finland. The latest experiments have been performed with a modified setup where the standard GREAT focal-plane double-sided silicon-strip detector was changed to a dual multi-wire proportional-counter arrangement. This new setup has improved capability for short-lived isomer studies where large focal-plane rates can be tolerated. The results of key recent experiments for nuclei situated above ({sup 153}Yb, {sup 152}Tm) and below ({sup 144}Ho, {sup 142}Tb) the N = 82 shell gap were presented. These studies have charted the evolution of isomeric states across the neutron shell from K-Isomers at N = 74, to shape isomers at N = 77 and shell-model isomers at N = 82, 83. The excitation energies for some of the lowest-lying excited states in these isomeric nuclei show behaviour which is characteristic of an X(5) symmetry falling midway between the limits expected for pure vibrational and rotational behaviour. The future prospects for studies of these nuclei were discussed using an isomer-tagged differential-plunger setup. This technique will be capable of establishing the deformation of the states above the isomers and will aid in determining whether their behaviour is indeed well described by the X(5) symmetry limit.

Cullen, D. M.; Mason, P. J. R.; Khan, S.; Kishada, A. M.; Varley, B. J. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Rigby, S. V. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Oliver Lodge, Lab., University of Liverpool, Liverpool, L69 7ZE (United Kingdom); Scholey, C.; Greenlees, P.; Rahkila, P.; Jones, P. M.; Julin, R.; Juutinen, S.; Leino, M.; Leppaenen, A. P.; Nyman, M.; Uusitalo, J. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae, FIN-40014 (Finland); Grahn, T.; Pakarinen, J. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae, FIN-40014 (Finland); Oliver Lodge, Lab., University of Liverpool, Liverpool, L69 7ZE (United Kingdom); Nieminen, P. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae, FIN-40014 (Finland); Department of Nuclear Physics, Australian National University, Canberra, ACT 0200 (Australia)

2008-05-12T23:59:59.000Z

79

Photoproduction of mesons off nuclei  

E-Print Network (OSTI)

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

B. Krusche

2011-10-02T23:59:59.000Z

80

Muon Capture in Heavy Nuclei  

Science Journals Connector (OSTI)

The systematics of muon capture rates in complex nuclei is discussed in the closure approximation. It is shown that for calculations in infinite nuclear matter, the nuclear ground state can be reasonably approximated by an infinite Fermi gas. The closure approximation and Fermi-gas model for the nuclear ground state are then used in an analysis of the experimental capture rates in a large number of nuclei. We find that this procedure does allow one to satisfactorily interpret quantitatively the muon-capture rates in the heavier nuclei and that it is possible to interpret the analysis in a manner which is not inconsistent with a universal Fermi interaction. The possibility of using muon capture rates to determine a neutron-proton nuclear-radius difference is also explored but with negative results.

R. Klein

1966-06-17T23:59:59.000Z

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

Counter-Rotating Tandem Motor Drilling System  

SciTech Connect

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

82

Neutron scattering on deformed nuclei  

Science Journals Connector (OSTI)

Measurements of neutron elastic and inelastic differential cross sections around 14 MeV for 9Be C 181 Ta 232Th 238U and 239Pu have been analyzed using a coupled channel (CC) formalism for deformed nuclei and phenomenological global optical model potentials (OMP). For the actinide targets these results are compared with the predictions of a semi?microscopic calculation using Jeukenne Lejeune and Mahaux (JLM) microscopic OMP and a deformed ground state nuclear density. The overall agreement between calculations and the measurements is reasonably good even for the very light nuclei where the quality of the fits is better than those obtained with spherical OMP.

L. F. Hansen; R. C. Haight; B. A. Pohl; C. Wong; Ch. Lagrange

1985-01-01T23:59:59.000Z

83

Proton Distribution in Heavy Nuclei  

DOE R&D Accomplishments (OSTI)

It is reasoned that, from considerations connected with beta-decay stability and Coulomb repulsion forces, a neutron excess is developed on the surface of heavy nuclei. Several consequences of this qualitative analysis in nucleon interactions are briefly noted. (K.S.)

Johnson, M. H; Teller, E.

1953-11-13T23:59:59.000Z

84

Electrons and Nuclei: Fundamental Interactions and Structure  

E-Print Network (OSTI)

Examples are given of the usefulness of electrons in interaction with nuclei for probing fundamental interactions and structure

Ernest M. Henley

1998-01-14T23:59:59.000Z

85

Neutron-deficient nuclei studied with stable and radioactive beams  

Science Journals Connector (OSTI)

...radioactive nuclei compiled by W. Gelletly Neutron-deficient nuclei studied with stable and radioactive beams Neutron-deficient nuclei close to the proton...proton drip-line|radioactive beams| Neutron-deficient nuclei studied with stable...

1998-01-01T23:59:59.000Z

86

Development of neutron multiplicity counters for safeguards assay  

SciTech Connect

This paper reports on the development of a new generation of neutron multiplicity counters for assaying impure plutonium. The new counters will be able to obtain three measured parameters from the neutron multiplicity distribution and will be able to determine sample mass, multiplication, and (..cap alpha..,n) reaction rate, making it possible to obtain a more matrix-independent assay of moist or impure materials. This paper describes the existing prototype multiplicity counters and evaluates their performance using assay variance as a figure of merit. The best performance to date is obtained with a high-efficiency, low die-away-time thermal neutron counter with shift-register electronics. 10 refs., 2 figs., 4 tabs.

Ensslin, N.

1989-01-01T23:59:59.000Z

87

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

88

MHK Technologies/Sub Surface Counter Rotation Current Generator | Open  

Open Energy Info (EERE)

Sub Surface Counter Rotation Current Generator Sub Surface Counter Rotation Current Generator < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Sub Surface Counter Rotation Current Generator.jpg Technology Profile Primary Organization Cyclocean LLC Technology Type Click here Axial Flow Turbine Technology Readiness Level Click here TRL 7 8 Open Water System Testing Demonstration and Operation Technology Description Self regulated sub surface current generators that operate independently that tether freely anchored offshore in deep waters in the Gulf Stream Current producing continuos clean energy for the eastern seaboard Technology Dimensions Device Testing Date Submitted 20:10.1 << Return to the MHK database homepage Retrieved from "http://en.openei.org/w/index.php?title=MHK_Technologies/Sub_Surface_Counter_Rotation_Current_Generator&oldid=681657

89

Context Mediation Demonstration of Counter-Terrorism Intelligence Integration  

E-Print Network (OSTI)

In this report, we demonstrate the applicability and value of the context mediation approach in facilitating the effective and correct use of counter-terrorism intelligence information coming from diverse heterogeneous sources.

Madnick, Stuart E.

2005-05-27T23:59:59.000Z

90

Introduction to Neutron Coincidence Counter Design Based on Boron-10  

SciTech Connect

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

91

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

92

Influence of light nuclei on neutrino-driven supernova outflows  

E-Print Network (OSTI)

We study the composition of the outer layers of a protoneutron star and show that light nuclei are present in substantial amounts. The composition is dominated by nucleons, deuterons, tritons and alpha particles; 3He is present in smaller amounts. This composition can be studied in laboratory experiments with new neutron-rich radioactive beams that can reproduce similar densities and temperatures. After including the corresponding neutrino interactions, we demonstrate that light nuclei have a small impact on the average energy of the emitted electron neutrinos, but are significant for the average energy of antineutrinos. During the early post-explosion phase, the average energy of electron antineutrinos is slightly increased, while at later times during the protoneutron star cooling it is reduced by about 1 MeV. The consequences of these changes for nucleosynthesis in neutrino-driven supernova outflows are discussed.

A. Arcones; G. Martinez-Pinedo; E. O'Connor; A. Schwenk; H. -Th. Janka; C. J. Horowitz; K. Langanke

2008-05-25T23:59:59.000Z

93

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

94

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

95

Shell-Model Analysis for Brueckner Calculations in Light Nuclei  

Science Journals Connector (OSTI)

Brueckner self-consistent calculations are performed for O16, H3, and He4 nuclei with various modern hard-core interactions. Elements of the G matrix are calculated by the reference-spectrum method, while Q-1 corrections are made by matrix inversion in the proper single-particle space. Thus, it is not assumed that Q commutes with the center-of-mass motion. The prescription for selecting the appropriate spectrum of single-particle excited states is investigated by comparing results of the Brueckner method with other calculations. These comparisons indicate that the particle spectrum should be left unperturbed. One then finds that the Hamada-Johnston, Yale, and Reid (hard-core) interactions yield about one half the binding energy of O16. The calculated results are dissected into shell-model components. This analysis indicates that the short-range part of the hard-core interaction is too strongly repulsive.

Ram K. Tripathi and Paul Goldhammer

1972-07-01T23:59:59.000Z

96

Carbonaceous Aerosols and Radiative...  

NLE Websites -- All DOE Office Websites (Extended Search)

and absorption of light by aerosols. At the ground sites, a new Humidigraph, a Cloud Condensation Nuclei Counter, a Scanning Mobility Particle Sizer, and an upgraded 915-MHz...

97

ARM Cloud Aerosol Precipitation Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Satellite Observation CAS Cloud Aerosol Spectrometer CCN Cloud Condensation Nuclei CIP Cloud Imaging Probe CPC Condensation Particle Counter CSPHOT Cimel sunphotometer CVI...

98

High spins in gamma-soft nuclei  

SciTech Connect

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

99

On Tensor Forces and the Theory of Light Nuclei  

Science Journals Connector (OSTI)

The quadrupole moment of the deuteron indicates the existence of non-central tensor forces in nuclei which destroy the constancy of the total orbital angular momentum. With simple operational representations of the wave functions, the influence of two-body tensor forces on the ground state eigenfunctions of the light nuclei H3 and He4 has been calculated. In H3 the tensor forces directly couple to the fundamental S122 state a D124 state, which in turn interacts with P122 and P124. To the fundamental S01 state of He4 is admixed a D05 state which is coupled by the tensor forces with P03. All states consistent with the total angular momentum and parity conservation rules occur in the ground state eigenfunctions, and these nuclei therefore constitute the simplest examples of the complete break-down of spin and orbital angular momentum conservation laws. Rarita and Schwinger have satisfactorily accounted for the properties of the deuteron by including the tensor force in a simple interaction represented by a rectangular well potential. With this interaction to describe the forces between all pairs of nuclear particles, the binding energies of H3 and He4 have been estimated by a variation method The trial functions are of the form S122+D124 for H3 and S01+D05 for He4, with Gaussian radial functions. The calculations yield 32 and 50 percent of the binding energy for H3 and He4, respectively, while a similar test calculation for the deuteron gives 54 percent of the binding energy. The probability that these nuclei are in a D state is found to be 4 percent for all three nuclei, in agreement with the exact deuteron computations. Improvement of the radial dependence of the trial functions increases the estimated binding energy of the deuteron to 76 percent of the known value but does not materially affect either the estimated binding energies of H3 and He4, or the amount of D state admixture of the three nuclei. An analysis of the results shows that the tensor forces, which produce all the binding in the deuteron, are relatively ineffective in binding H3 and He4. This apparently indicates that the assumption of ordinary and tensor forces of the same range is not adequate to represent the properties of H3 and He4.

Edward Gerjuoy and Julian Schwinger

1942-02-01T23:59:59.000Z

100

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

E-Print Network (OSTI)

.kostic.niu.edu Pressure Reduction Unit TOTAL CNC CNC DMA 1 DMA 2 Exhaust (concentration) (size) (size) CNC HPLPC Rosemount - Differential Mobility Analyzer CNC ­ Condensation Nuclei Counter HPLPC ­ High Pressure Large Particle Counter

Kostic, Milivoje M.

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

Boron-Lined Multitube Neutron Proportional Counter Test  

SciTech Connect

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

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

2010-09-07T23:59:59.000Z

102

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-expertise, environmental activism, France, lay knowledge, nuclear power, scientists' mobilization, social studies

Gutkin, Boris

103

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

104

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

105

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

106

Characteristic parameters of geigermüller counter gases. Propane-argon and propane-helium mixtures  

Science Journals Connector (OSTI)

The combination of the Wilkinson and the Diethorn-Kohman expressions of counter operation was tested under conditions in which different rare gases were used with the same quench gas as Geiger-Müller counter f...

Richard G. Pannbacker; Robert W. Kiser

1962-02-01T23:59:59.000Z

107

Radiative muon capture in nuclei  

Science Journals Connector (OSTI)

The energy spectra of photons following negative muon absorption in C12, O16, Al27, Ca40, Fenat, Ho165, and Bi209 have been measured with two NaI spectrometers. The branching ratios for the emission of high energy photons give information on the induced pseudoscalar coupling constant gP in nuclear matter. The data for light nuclei are in agreement with the theoretical calculations using the nucleonic value of gP?7gA predicted by the partially conserved axial vector current hypothesis, while significantly lower values of gP are required to fit the data of the heavier elements with presently existing theoretical predictions. Disregarding the remaining theoretical uncertainties, these results can be interpreted as a further indication of the renormalization of the nucleonic form factors inside the nucleus.

M. Döbeli; M. Doser; L. van Elmbt; M. W. Schaad; P. Truöl; A. Bay; J. P. Perroud; J. Imazato; T. Ishikawa

1988-04-01T23:59:59.000Z

108

Competition in rotation-alignment between high-j neutrons and protons in transfermium nuclei  

SciTech Connect

The study of rotation-alignment of quasiparticles probes sensitively the properties of high-j intruder orbits. The distribution of very-high-j orbits, which are consequences of the fundamental spin-orbit interaction, links with the important question of single-particle levels in superheavy nuclei. With the deformed single-particle states generated by the standard Nilsson potential, we perform Projected Shell Model calculations for transfermium nuclei where detailed spectroscopy experiments are currently possible. Specifically, we study the systematical behavior of rotation-alignment and associated band-crossing phenomenon in Cf, Fm, and No isotopes. Neutrons and protons from the high-j orbits are found to compete strongly in rotation-alignment, which gives rise to testable effects. Observation of these effects will provide direct information on the single-particle states in the heaviest nuclear mass region.

Al-Khudair, Falih [Department of Physics, Tsinghua University, Beijing 100084 (China); Center of Nuclear Theory, Lanzhou National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); Department of Physics, College of Education, Basrah University, Basrah (Iraq); Long Guilu [Department of Physics, Tsinghua University, Beijing 100084 (China); Center of Nuclear Theory, Lanzhou National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); Sun Yang [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2009-03-15T23:59:59.000Z

109

Towards Fuzzy Techniques for Capturing Subjective (Human) Aspects of Counter-Terrorism Planning: Optimizing Trajectories  

E-Print Network (OSTI)

Towards Fuzzy Techniques for Capturing Subjective (Human) Aspects of Counter-Terrorism Planning Abstract-- At first glance, most aspects of counter-terrorism activity look like classical examples of zero of each participant; in contrast, in counter-terrorism planning, the adversary's objective function

Ward, Karen

110

Particle Astrophysics  

NLE Websites -- All DOE Office Websites (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...

111

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

112

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

SciTech Connect

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

113

''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

114

Fusion Reactor Plasmas with Polarized Nuclei  

Science Journals Connector (OSTI)

Nuclear fusion rates can be enhanced or suppressed by polarization of the reacting nuclei. In a magnetic fusion reactor, the depolarization time is estimated to be longer than the reaction time.

R. M. Kulsrud; H. P. Furth; E. J. Valeo; M. Goldhaber

1982-10-25T23:59:59.000Z

115

From Nucleons To Nuclei To Fusion Reactions  

SciTech Connect

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

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

2012-02-15T23:59:59.000Z

116

Spectroscopy of gallium selenide nanoparticle nuclei  

E-Print Network (OSTI)

by the presence of GaSe nanoparticle nuclei which are non-Superradiance in GaSe Nanoparticle Aggregates”, Journal ofStrongly-Coupled GaSe Nanoparticle Aggregates”, Journal of

Lair, Deborah L.

2011-01-01T23:59:59.000Z

117

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.

118

CSP-based counter abstraction for systems with node identifiers  

Science Journals Connector (OSTI)

Abstract The Parameterised Model Checking Problem asks whether an implementation I m p l ( t ) satisfies a specification S p e c ( t ) for all instantiations of parameter  t . In general, t  can determine numerous entities: the number of processes used in a network, the type of data, the capacities of buffers, etc. The main theme of this paper is automation of uniform verification of a subclass of PMCP with the parameter of the first kind, i.e. where it determines the number of processes used in a network. We use CSP as our formalism. Counter abstraction is a technique that replaces a concrete state space by an abstract one, where each abstract state is a tuple of integer counters ( c 1 , … , c k ) such that for each  i , c i counts how many node processes are currently in the i -th state. Each counter c i is given a finite threshold z i and we interpret c i = z i as there being z i or more processes in the i -th state. Standard counter abstraction techniques require all processes to be identical, which means that nodes cannot use node identifiers. In this paper we present how counter abstraction techniques can be extended to processes that make use of node identifiers in a symmetrical way. Our method creates a process A b s t r that is independent of  t and is refined by ? ( I m p l ( T ) ) for all sufficiently large  T , where ? maps all (sufficiently large) instantiations T of the parameter to some fixed type. By transitivity of refinement, testing if A b s t r refines S p e c ( ? ( t ) ) implies that S p e c ( ? ( t ) ) is refined by ? ( I m p l ( T ) ) . Then, using the type reduction theory from Mazur and Lowe (2012) [29], we can deduce that S p e c ( T ) is refined by I m p l ( T ) for all sufficiently large T , thus obtaining a positive answer to the original verification problem.

Tomasz Mazur; Gavin Lowe

2014-01-01T23:59:59.000Z

119

Nuclear structure and reactions with stored nuclei  

SciTech Connect

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

120

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

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

Pair-truncated shell-model analysis of nuclei around mass 130  

SciTech Connect

Low-lying states for even-even, odd-mass, and doubly odd nuclei in the mass A{approx}130 region are systematically investigated using a pair-truncated shell model. In this model the collective nucleon pairs with angular momenta zero and two are the basic ingredients for even-even nuclei. Additional unpaired nucleons are added to the even-even core for a description of odd-mass and doubly odd nuclei. The effective interactions consist of single-particle energies and monopole and quadrupole pairing plus quadrupole-quadrupole interactions, whose strengths are assumed to be linearly changed as functions of the number of nucleons so as to describe the level schemes of the even-even and odd-mass nuclei. Energy levels of the low-lying collective states for even-even Xe, Ba, Ce, and Nd isotopes are reproduced very well along with intraband and interband B(E2) values, which simulate the typical features of the O(6) limit of the interacting boson model. For odd-mass and doubly odd nuclei, complicated level schemes and electromagnetic moments are in excellent agreement with the experimental data.

Higashiyama, Koji [Department of Physics, Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan); Yoshinaga, Naotaka [Department of Physics, Saitama University, Saitama City 338-8570 (Japan)

2011-03-15T23:59:59.000Z

122

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

SciTech Connect

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

123

A study of an improved aperture for an electronic particle counter  

E-Print Network (OSTI)

under the copper wire. i ot, rminations were made by f. lling the graduated & o i smn and slowly drai ning thc column until the sma' 1 copper wir, . c auld just o& seen This proces. was repeated several Ci mes. The flu Ld level in the graduated... expression. Ponder, in 1935, was the f irsc to ma)e a comprehensive study of- an optical method for blood cell counting and 5 sizing. Hi. s measurements were made with a standard spec- tophotometer incorpor atirg a creen filter with max. 'mum...

Douglas, John Hardwick

2012-06-07T23:59:59.000Z

124

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

125

Strictly finite-range potential for light and heavy nuclei  

Science Journals Connector (OSTI)

Strictly finite-range (SFR) potentials are exactly zero beyond their finite range. Single-particle energies and densities, as well as S-matrix pole trajectories, are studied in a few SFR potentials suited for the description of neutrons interacting with light and heavy nuclei. The SFR potentials considered are the standard cutoff Woods-Saxon (CWS) potentials and two potentials approaching zero smoothly: the SV potential introduced by Salamon and Vertse [Phys. Rev. C 77, 037302 (2008)] and the SS potential of Sahu and Sahu [Int. J. Mod. Phys. E 21, 1250067 (2012)]. The parameters of these latter potentials were set so that the potentials may be similar to the CWS shape. The range of the SV and SS potentials scales with the cube root of the mass number of the core like the nuclear radius itself. For light nuclei a single term of the SV potential (with a single parameter) is enough for a good description of the neutron-nucleus interaction. The trajectories are compared with a benchmark for which the starting points (belonging to potential depth zero) can be determined independently. Even the CWS potential is found to conform to this benchmark if the range is identified with the cutoff radius. For the CWS potentials some trajectories show irregular shapes, while for the SV and SS potentials all trajectories behave regularly.

P. Salamon; R. G. Lovas; R. M. Id Betan; T. Vertse; L. Balkay

2014-05-13T23:59:59.000Z

126

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

127

Toward open-shell nuclei with coupled-cluster theory  

SciTech Connect

We develop a method based on equation-of-motion coupled-cluster theory to describe properties of open-shell nuclei with A{+-}2 nucleons outside a closed shell. We perform proof-of-principle calculations for the ground states of the helium isotopes {sup 3-6}He and the first excited 2{sup +} state in {sup 6}He. The comparison with exact results from matrix diagonalization in small model spaces demonstrates the accuracy of the coupled-cluster methods. Three-particle-one-hole excitations of {sup 4}He play an important role for the accurate description of {sup 6}He. For the open-shell nucleus {sup 6}He, the computational cost of the method is comparable with the coupled-cluster singles-and-doubles approximation while its accuracy is similar to the coupled-cluster with singles, doubles, and triples excitations.

Jansen, G. R.; Hjorth-Jensen, M. [Department of Physics and Center of Mathematics for Applications, University of Oslo, N-0316 Oslo (Norway); Hagen, G. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Papenbrock, T. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)

2011-05-15T23:59:59.000Z

128

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

129

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

130

Coincidence counter design for the assay of vitrified nuclear waste  

SciTech Connect

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

131

Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC  

SciTech Connect

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

132

Jacobi shape transition in fp shell nuclei  

Science Journals Connector (OSTI)

Jacobi shape transition from noncollective oblate to super or hyperdeformed collective prolate or triaxial shape taking place in rotating nuclei as in the case of gravitating rotating stars is studied in fp shell nuclei 44Ti, 48Cr, 52Fe, and 56Ni. The cranked Nilsson-Strutinsky method is used to detect such transition. The method of tuning the angular velocity to get fixed spin is utilized in these calculations. Pairing is not taken into account since Jacobi transition occurs only at very high spin where pairing correlations would have already vanished. Our results show that all the four nuclei considered in this work are good candidates for detecting the Jacobi shape transition.

G. Shanmugam; V. Ramasubramanian; S. N. Chintalapudi

2001-05-10T23:59:59.000Z

133

Coulomb dissociation of light nuclei  

Science Journals Connector (OSTI)

We present an alternative theoretical formulation of the Coulomb dissociation process. We apply the formalism to the deuteron as an example of a weakly bound two-body composite nucleus with a charged core and a neutral valence particle and for which exclusive experimental data exist in an appropriate kinematical regime. The theoretical scheme assumes that the projectile excitation is predominantly to states with low internal energy and is expected to be applicable at incident projectile energies of tens of MeV per nucleon and above. A readily calculable expression for the quantum mechanical breakup transition amplitude is obtained without the use of the distorted-wave Born approximation weak channel coupling approximation or of additional approximations for finite-range effects. Calculations are presented, analyzed, and compared with high precision, kinematically complete, measurements of elastic deuteron dissociation into very forward scattering angles. The calculations and data support the importance of the Coulomb breakup mechanism under these kinematical conditions.

J. A. Tostevin; S. Rugmai; R. C. Johnson

1998-06-01T23:59:59.000Z

134

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

135

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

E-Print Network (OSTI)

) Michael Wesley Mallett, B. S. , Texas A&M University; M. S. , Texas A&M University Chair of Advisory Committee: Dr. John W. Poston Hydro Nuclear Services, Inc. manufactured the Universal Body Counter, a unique in-vi vo system featuring a moving... the detector is offered as one solution to this problem. The Universal Body Counter is compared to other counters having similar features. Those whole body counters considered are the Canberra Accuscan II, the Helgeson Do-It-Yourself, and the Nuclear Data...

Mallett, Michael Wesley

2012-06-07T23:59:59.000Z

136

Particle Physics Booklet 2008  

E-Print Network (OSTI)

nuclei follow the solar abundance ratios. The exception isfactor relative to solar abundance, probably due to the

et al., C. Amsler

2008-01-01T23:59:59.000Z

137

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

138

Searching for X(5) behavior in nuclei  

Science Journals Connector (OSTI)

We have searched even-even nuclei with Z>~20, N>~20 to find examples displaying the predicted characteristics of X(5) critical point behavior. On the basis of the yrast state energies and yrast intraband transition strengths, the best candidates are 126Ba, 130Ce, and the previously suggested examples of the N=90 isotones of Nd, Sm, Gd, and Dy.

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

2003-09-03T23:59:59.000Z

139

Transfer-induced fission of superheavy nuclei  

SciTech Connect

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

140

Magnetic field outflows from active galactic nuclei  

Science Journals Connector (OSTI)

We examine several models of injecting magnetic fields into clusters of galaxies from active galactic nuclei, which are the powerful outflows associated with supermassive black holes in the centers of clusters. Shown are magnetic field lines after six ... Keywords: scientific visualization

David Pugmire; Paul Sutter; Paul Ricker; Hsiang-Yi (Karen) Yang; George Foreman

2011-11-01T23:59:59.000Z

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

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

142

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

143

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 A<284. Beta-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

144

Particle Lifetimes  

NLE Websites -- All DOE Office Websites (Extended Search)

Reviewing Particle Lifetimes Reviewing Particle Lifetimes The lifetimes of elementary particles are statistical in nature. In a given sample, one particle might decay immediately, another in 1 nanosecond, yet another after 10 milliseconds, and still another in 50 years. What we call the lifetime is the time it takes for a sample to decay so 1/e (~30%) of the sample is left; after 2 lifetimes, 1/e2 of the sample is left, and so on. Take, for example, a sample of cosmic ray muons produced in the upper atmosphere. These muons, when observed at (relative) rest in the laboratory, have a mean lifetime T. Now, since particle decay is statistical in nature, the number of undecayed particles after a given time is a negative exponential function: N(t) = No e-t/T where N(t) is the number of muons at time t, No is the initial number of

145

Alignment Delays in the N=Z Nuclei K72r, S76r, and Z80r  

Science Journals Connector (OSTI)

The ground state rotational bands of the N=Z nuclei 72Kr, 76Sr, and 80Zr have been extended into the angular momentum region where rotation alignment of particles is normally expected. By measuring the moments of inertia of these bands we have observed a consistent increase in the rotational frequency required to start pair breaking, when compared to neighboring nuclei. 72Kr shows the most marked effect. It has been widely suggested that these “delayed alignments” arise from np-pairing correlations. However, alignment frequencies are very sensitive to shape degrees of freedom and normal pairing, so the new experimental observations are still open to interpretation.

S. M. Fischer; C. J. Lister; D. P. Balamuth; R. Bauer; J. A. Becker; L. A. Bernstein; M. P. Carpenter; J. Durell; N. Fotiades; S. J. Freeman; P. E. Garrett; P. A. Hausladen; R. V. F. Janssens; D. Jenkins; M. Leddy; J. Ressler; J. Schwartz; D. Svelnys; D. G. Sarantites; D. Seweryniak; B. J. Varley; R. Wyss

2001-09-04T23:59:59.000Z

146

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

147

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.

148

Knowing the Enemy: A Simulation of Terrorist Organizations and Counter-Terrorism Strategies  

E-Print Network (OSTI)

Knowing the Enemy: A Simulation of Terrorist Organizations and Counter-Terrorism Strategies Maksim@ece.cmu.edu Abstract Given the increasing threat of terrorism and spread of terrorist organizations, it is of vital: A Simulation of Terrorist Organizations and Counter-Terrorism Strategies Maksim Tsvetovat and Kathleen Carley

Sadeh, Norman M.

149

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

150

Possibilistic clustering approach to trackless ring Pattern Recognition in RICH counters  

Science Journals Connector (OSTI)

The pattern recognition problem in Ring Imaging CHerenkov (RICH) counters concerns the identification of an unknown number of rings whose centers and radii are assumed to be unknown. In this paper we present an algorithm based on the possibilistic approach ... Keywords: 07.05.Mh, 29.40.Ka, 29.85.+c, Pattern recognition, Possibilistic clustering, RICH counters

A. M. Massone; L. Studer; F. Masulli

2006-02-01T23:59:59.000Z

151

Photoproduction of pi0-mesons from nuclei  

E-Print Network (OSTI)

Photoproduction of neutral pions from nuclei (carbon, calcium, niobium, lead) has been studied for incident photon energies from 200 MeV to 800 MeV with the TAPS detector using the Glasgow photon tagging spectrometer at the Mainz MAMI accelerator. Data were obtained for the inclusive photoproduction of neutral pions and the partial channels of quasifree single pi0, double pi0, and pi0pi+/- photoproduction. They have been analyzed in terms of the in-medium behavior of nucleon resonances and the pion - nucleus interaction. They are compared to earlier measurements from the deuteron and to the predictions of a Boltzmann-Uehling-Uhlenbeck (BUU) transport model for photon induced pion production from nuclei.

B. Krusche; J. Lehr; J. Ahrens; J. R. M. Annand; R. Beck; F. Bloch; L. S. Fog; D. Hornidge; S. Janssen; M. Kotulla; J. C. McGeorge; I. J. D. MacGregor; J. Messchendorp; V. Metag; U. Mosel; R. Novotny; R. O. Owens; M. Pfeiffer; R. Sanderson; S. Schadmand; D. P. Watts

2004-06-01T23:59:59.000Z

152

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

153

Particle identification at an asymmetric B Factory  

SciTech Connect

Particle identification systems are an important component of any detector at a high-luminosity, asymmetric B Factory. In particular, excellent hadron identification is required to probe CP violation in B{sup 0} decays to CP eigenstates. The particle identification systems discussed below also provide help in separating leptons from hadrons at low momenta. We begin this chapter with a discussion of the physics motivation for providing particle identification, the inherent limitations due to interactions and decays in flight, and the requirements for hermiticity and angular coverage. A special feature of an asymmetric B Factory is the resulting asymmetry in the momentum distribution as a function of polar angle; this will also be quantified and discussed. In the next section the three primary candidates, time-of-flight (TOF), energy loss (dE/dx), and Cerenkov counters, both ring-imaging and threshold, will be briefly described and evaluated. Following this, one of the candidates, a long-drift Cerenkov ring-imaging device, is described in detail to provide a reference design. Design considerations for a fast RICH are then described. A detailed discussion of aerogel threshold counter designs and associated R D conclude the chapter. 56 refs., 64 figs., 13 tabs.

Coyle, P.; Eigen, G.; Hitlin, D.; Oddone, P.; Ratcliff, B.; Roe, N.; Va'vra, J.; Ypsilantis, T.

1991-09-01T23:59:59.000Z

154

Isovector excitations of N?Z nuclei  

Science Journals Connector (OSTI)

We show that the method based on the tensor coupling of an appropriate family of isovector excitation operators to the parent isospin multiplet can be used to advantage for the correct treatment of the isospin degree of freedom in nonisoscalar nuclei. This method is applicable to any isovector excitation operator and for parent states which need not be of the closed subshells type. As an illustration we apply it to the study of the Gamow-Teller transition strength in Zr90.

E. J. V. de Passos; D. P. Menezes; A. P. N. R. Galeao

1987-12-01T23:59:59.000Z

155

Polarization of Nucleons Elastically Scattered by Nuclei  

Science Journals Connector (OSTI)

The polarization of 424-Mev nucleons elastically scattered by nuclei is calculated by a method which is similar to the Born approximation, but in which the phase shifts of the incident plane wave due to the scattering potential is taken into consideration. A qualitative agreement with the experimental result is obtained if one uses the well parameters determined by Riesenfeld and Watson. Poor agreement at the diffraction minimum may be attributed to the existence of inelastic scattering in the experimental data.

Keiichi Nishimura

1958-06-01T23:59:59.000Z

156

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

2012-05-29T23:59:59.000Z

157

Improved Technology To Prevent Nuclear Proliferation And Counter Nuclear Terrorism  

SciTech Connect

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

158

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

159

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

160

Certification of Plutonium Standards for KAMS Neutron Multiplicity Counter  

SciTech Connect

As part of the implementation of the PEIS record of decision in January of 1997, DOE will pursue two technologies to disposition fifty metric tons of its stockpile of plutonium. As a result of this and in order to expedite the closure of Rocky Flats Environmental Technology Site in Colorado, DOE decided to use existing facilities at the Savannah River Site (SRS) for storing all material containing plutonium at KAMS. A neutron multiplicity counter was designed and built to carry out receipt verification measurement at the facility. Since the material covers a wide range and different levels of impurities, it is essential that we obtain a set of working standards. An agreement was drafted to select the first drums to be these standards. A plan was developed for the certification of these standards using Rocky Flat's existing nondestructive assay equipment. This paper will discuss the types of materials to be shipped to SRS, number of standards to certify for each type of material, and the certification plan. It will also discuss the activities necessary to determine the nuclear content of these working standards to be used at SRS facilities in support of shipment and receipt of the Pu containing materials. Definition of instrument qualifications, measurement control processes, measurement methodologies, and calculations necessary to report the gram quantities and their uncertainties for plutonium, americium-241, uranium-235 (if present) and neptunium-237 (if present) will also be presented.

Salaymeh, S.R.

2002-05-31T23:59:59.000Z

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161

Multisection gas counters for spectral studies of weak pulse x-radiation  

SciTech Connect

This paper describes two multisection gas counters for recording pulse x-radiation. The first design is a set of eight tandem cylindrical gas counters and the second design is a sixsection gas scintillation counter. These detectors measure the free path length of radiation in the gas filling them, form the measurement data using the maximum-liklihood method, and a computer satisfactorily reconstructs the x-ray spectra, when the total number of absorbed photons Np about 10/sup 2/ for one pulse with a duration of less than or equal to 1 usec.

Bogomolov, G.D.; Kravchenko, N.A.; Peskov, V.D.; Podolyak, E.R.

1986-02-01T23:59:59.000Z

162

Thomson scattering measurement of a shock in laser-produced counter-streaming plasmas  

SciTech Connect

We report the first direct measurement of temporally and spatially resolved plasma temperatures at a shock as well as its spatial structure and propagation in laser-produced counter-streaming plasmas. Two shocks are formed in counter-streaming collisionless plasmas early in time, and they propagate opposite directions. This indicates the existence of counter-streaming collisionless flows to keep exciting the shocks, even though the collisional effects increase later in time. The shock images are observed with optical diagnostics, and the upstream and downstream plasma parameters of one of the shocks are measured using Thomson scattering technique.

Morita, T.; Kuramitsu, Y.; Moritaka, T. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan)] [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Sakawa, Y.; Takabe, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan) [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan); Tomita, K.; Nakayama, K.; Inoue, K.; Uchino, K. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan)] [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Ide, T.; Tsubouchi, K. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)] [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishio, K.; Ide, H.; Kuwada, M. [Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan)] [Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan)

2013-09-15T23:59:59.000Z

163

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

164

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

165

Observations of new aerosol particle formation in a tropical urban Raghu Betha a  

E-Print Network (OSTI)

fires were observed during the course of air sampling due to a prolonged dry spell in the months particles are also formed in the atmosphere through gas-to-particle conversion; this phenomenon is often on climate, especially on the number of cloud condensation nuclei (CCN) and the resulting ef- fects on cloud

Spracklen, Dominick

166

ARM - Data Announcements Article  

NLE Websites -- All DOE Office Websites (Extended Search)

Surface Cloud Condensation Nuclei Average Evaluation Product Available Surface Cloud Condensation Nuclei Average Evaluation Product Available Bookmark and Share This plot shows the concentration of CCN measured by the cloud condensation particle counter versus the concentration measured by the condensation particle counter. This plot shows the concentration of CCN measured by the cloud condensation particle counter versus the concentration measured by the condensation particle counter. Aerosol observing systems (AOS) at ARM's sites measure cloud condensation nuclei (CCN) at several supersaturations using a single-column CCN counter. The Average of Cloud Condensation Nuclei from AOS (AOSCCNAVG) value-added product (VAP) was developed to consolidate the relevant CCN parameters into a single file and average data over the 5-minute integration time of each

167

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

SciTech Connect

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.

Tarifeño-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

168

Trillion Particles,  

NLE Websites -- All DOE Office Websites (Extended Search)

Trillion Trillion Particles, 120,000 cores, and 350 TBs: Lessons Learned from a Hero I/O Run on Hopper Surendra Byna ∗ , Andrew Uselton ∗ , Prabhat ∗ , David Knaak † , and Yun (Helen) He ∗ ∗ Lawrence Berkeley National Laboratory, USA. Email: {sbyna, acuselton, prabhat, yhe}@lbl.gov † Cray Inc., USA. Email: knaak@cray.com Abstract-Modern petascale applications can present a variety of configuration, runtime, and data management challenges when run at scale. In this paper, we describe our experiences in running VPIC, a large-scale plasma physics simulation, on the NERSC production Cray XE6 system Hopper. The simulation ran on 120,000 cores using ∼80% of computing resources, 90% of the available memory on each node and 50% of the Lustre scratch file system. Over two trillion particles were simulated for 23,000 timesteps, and 10 one-trillion particle dumps, each ranging between

169

Elementary Particles  

NLE Websites -- All DOE Office Websites (Extended Search)

Elementary Particles Elementary Particles Elementary Particles Detectors Accelerators Visit World Labs For Children - for younger people Electric Forces & Fields For Children The Electric Force For Children Electric Force Fields For Children Charges and Fields For Children Vibrating Charges and Electromagnetic Waves Electrons For Older People The Discovery of the Electron Traveling Waves For Older People Waves and Wave-Like Motion For Children Catch the Wave For Children Vibrating Charges and Electromagnetic Waves For Children Electromagnetic Waves Standing Waves For Older People Physics 128 Lecture Standing Waves For Older People Resonance in Strings and Springs For Older People Standing Wave - 1st Harmonic For Older People Standing Wave - 2nd Harmonic Atom For Older People Bohr Atom

170

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

SciTech Connect

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

171

Magnetic excitations in nuclei with neutron excess  

E-Print Network (OSTI)

The excitation of the $1^+$, $2^-$ and $3^+$ modes in $^{16}$O, $^{22}$O, $^{24}$O, $^{28}$O, $^{40}$Ca, $^{48}$Ca, $^{52}$Ca and $^{60}$Ca nuclei is studied with self-consistent random phase approximation calculations. Finite-range interactions of Gogny type, containing also tensor-isospin terms, are used. We analyze the evolution of the magnetic resonances with the increasing number of neutrons, the relevance of collective effects, the need of a correct treatment of the continuum and the role of the tensor force.

G. Co'; V. De Donno; M. Anguiano; A. M. Lallena

2012-03-13T23:59:59.000Z

172

Thermodynamics of nuclei in thermal contact  

Science Journals Connector (OSTI)

The thermodynamic properties of a dinuclear system are studied with the methods of statistical mechanics. A schematic model calculation shows that the excitation-energy transfer proceeds in energy steps of considerable amount which are subject to large fluctuations. As a consequence, thermal averaging is strong enough to assure the application of thermodynamical methods for describing the energy exchange between the two nuclei in contact. In particular, thermal averaging justifies the definition of a nuclear temperature. The division of excitation energy in thermal equilibrium is derived for several analytical descriptions of the level density.

Karl-Heinz Schmidt and Beatriz Jurado

2011-01-28T23:59:59.000Z

173

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

174

Cloud condensation nuclei in Western Colorado : observations and model predictions.  

E-Print Network (OSTI)

??Variations in the warm cloud?active portion of atmospheric aerosols, or cloud condensation nuclei (CCN), have been shown to impact cloud droplet number concentration and subsequently… (more)

Ward, Daniel Stewart

2010-01-01T23:59:59.000Z

175

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

176

Nuclear Computational Low Energy Initiative (NUCLEI) | The Ames...  

NLE Websites -- All DOE Office Websites (Extended Search)

in nuclei, few body systems, and electroweak processes), NIF (light-ion thermonuclear reactions in a terrestrially controlled plasma environment), MAJORANA and FNPB...

177

Neutron-halo nuclei in cold synthesis and cluster decay of heavy nuclei: Z=104 nucleus as an example  

Science Journals Connector (OSTI)

Nuclei at the neutron-drip line are studied. The light neutron-halo nuclei are found to play an important role for both cold fusion reactions and exotic cluster decay studies of heavy nuclei at the neutron-drip line. For cold fusion reactions, beams of neutron-halo nuclei are shown to occur as natural extensions of the conventional lighter beams but with the corresponding target nuclei as the heavy neutron-rich radioactive nuclei. Thus, in synthesizing the various isotopes of a neutron-rich cool compound nucleus, both the target and projectile nuclei have to be richer in neutrons, with their proton numbers remaining the same. On the other hand, neutron-halo (cluster) decays are favored for a relatively less neutron-rich parent nucleus. Possible consequences of this work for the shell structure effects in neutron-rich heavy nuclei are also pointed out. This follows from the fact that the so far observed phenomena of both cold fusion and cluster radioactivity are associated with closed or nearly closed shell nuclei. Calculations are made for 104274,288, using the quantum mechanical fragmentation theory for cold fusion reaction studies and a performed cluster model for cluster decay studies.

Raj K. Gupta; Sarbjit Singh; Gottfried Münzenberg; Werner Scheid

1995-05-01T23:59:59.000Z

178

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

179

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.

Yoshida, Kenichi

2014-01-01T23:59:59.000Z

180

Search for long lived heaviest nuclei beyond the valley of stability  

Science Journals Connector (OSTI)

The existence of long lived superheavy nuclei (SHN) is controlled mainly by spontaneous fission and ?-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 ?-decay half-lives along with the spontaneous fission and ?-decay half-lives of such nuclei are studied. The ?-decay half-lives of SHN with Z=102–120 are calculated in a quantum tunneling model with DDM3Y effective nuclear interaction using Q? values from three different mass formulas 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 et al. A possible source of discrepancy between the calculated ?-decay half-lives of some nuclei and the experimental data of GSI, JINR-FLNR, RIKEN, is discussed. In the region of Z=106–108 with N~ 160–164, the ?-stable SHN 106268Sg162 is predicted to have highest ?-decay half-life (T?~3.2 h) using Q? value from MMM. Interestingly, it is much greater than the recently measured T? (~22 s) of deformed doubly magic 108270Hs162 nucleus. A few fission-survived long-lived SHN which are either ?-stable or having large ?-decay half-lives are predicted to exist near 294110184, 293110183, 296112184, and 298114184. These nuclei might decay predominantly through ?-particle emission.

P. Roy Chowdhury, C. Samanta, and D. N. Basu

2008-04-23T23:59:59.000Z

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,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

182

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

183

Nuclear induced breakup of halo nuclei H. Esbensen  

E-Print Network (OSTI)

Nuclear induced breakup of halo nuclei H. Esbensen Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 G. F. Bertsch Institute for Nuclear Theory, University of Washington, Seattle made in calculating the nuclear induced breakup of halo nuclei. We find that a truncated coupled

Bertsch George F.

184

Fusion Reaction of Halo Nuclei: Proton Halo versus Neutron Halo  

Science Journals Connector (OSTI)

......February 2004 research-article Articles Fusion Reaction of Halo Nuclei: Proton Halo...Tsukuba, Tsukuba 305-8571, Japan. The fusion reaction of halo nuclei on heavy target...Schrodinger equation. We find that the fusion probability is enhanced by the presence......

Takashi Nakatsukasa; Kazuhiro Yabana; Makoto Ito; Minoru Kobayashi; Manabu Ueda

2004-02-01T23:59:59.000Z

185

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

SciTech Connect

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

186

Fragmentation Barriers of Toroidal and Bubble Nuclei  

E-Print Network (OSTI)

those estimated recently from liquid-drop models [24,25]. We simulate the dynamics of nucleus-nucleus collisions with the Boltzmann-Uehling-Uhlenbeck equation [27] Bt " (27r)s dB+ v V?f~ ?V?U V'zfq ? d k2dO ""v12[fsf4(l ?f1)(1?f2) ?f~f2(1 ?fs)(1 ?f4.../49(4)/1778(5)/$06. 00 R1778 1994 The American Physical Society 49 FRAGMENTATION BARRIERS OF TOROIDAL AND BUBBLE NUCLEI R1779 TOP VIEW FRONT VIEW and 2 for 2Mo+ 2Mo collisions at E/A =75 MeV and b=0, for both the stifF (Fig. 1) and the soft (Fig. 2) equa- tions...

Xu, HM; Gagliardi, Carl A.; Tribble, Robert E.; Wong, C. Y.

1994-01-01T23:59:59.000Z

187

Mean field and collisions in hot nuclei  

SciTech Connect

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

188

Reggeon-calculus approach to high-energy scattering on nuclei  

Science Journals Connector (OSTI)

We apply Reggeon calculus to high-energy scattering on nuclei. Using methods similar to those of Abramovskii, Gribov, and Kancheli, we show that intranuclear cascading is forbidden. The inclusive spectrum is shown to be similar to that on hydrogen targets for rapidities ?ln(4Rm). We give rough arguments to derive the spectrum for y?y0 and show that our results are in qualitative agreement with the data. In weak-coupling theory elastic scattering from nuclei is shown to be factorizable and determined by one-Pomeron exchange. We speculate on the absorption length of the Pomeron in nuclear matter in "weak-coupling" and "strong-coupling" theories. Our model is compared with the "energy flux cascade" model of Gottfried and the Landau model. These have local particle production, in contrast to multiperipheralism, which involves large longitudinal distances. Crucial tests of our model are our predictions that the mean inelasticity of the leading particle is independent of A and the spectrum d?dy is (almost) independent of projectile species.

E. S. Lehman and G. A. Winbow

1974-11-01T23:59:59.000Z

189

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

190

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

SciTech Connect

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

191

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

NLE Websites -- All DOE Office Websites (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...

192

E-Print Network 3.0 - amphoter target nuclei Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

of Exotic Nuclei... of short-lived, unstable (radioactive) nuclei for ... Source: TRIUMF Isotope Separation and ACceleration (ISAC) facility, beta-NMR Group Collection: Physics 28...

193

the Fractional Flotation of Flotation Column Particles Opportunity  

NLE Websites -- All DOE Office Websites (Extended Search)

Enhancing Selectivity and Recovery in Enhancing Selectivity and Recovery in the Fractional Flotation of Flotation Column Particles Opportunity Although research is currently inactive on the patented technology "Method for Enhancing Selectivity and Recovery in the Fractional Flotation of Flotation Column Particles," the technology is available for licensing from the U.S. Department of Energy's National Energy Technology Laboratory (NETL). Disclosed in this patent is a method of particle separation from a feed stream comprised of particles of varying hydrophobicity by injecting the feed stream directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. The current invention allows the height of the feed stream injection and the reflux ratio to be

194

Fermilab | Science | Particle Accelerators  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle Accelerators Main Injector As America's particle physics laboratory, Fermilab operates and builds powerful particle accelerators for investigating the smallest things...

195

Statistics of particle time-temperature histories.  

SciTech Connect

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

196

Fermilab | Science | Particle Physics | Benefits of Particle...  

NLE Websites -- All DOE Office Websites (Extended Search)

Benefits of Particle Physics photo Each generation of particle accelerators and detectors builds on the previous one, raising the potential for discovery and pushing the level of...

197

COO-3072-119 RESULTS ON THE PERFORMANCE OF A BROAD BAND FOCUSSING CHERENKOV COUNTER*  

NLE Websites -- All DOE Office Websites (Extended Search)

3072-119 3072-119 ^ RESULTS ON THE PERFORMANCE OF A BROAD BAND FOCUSSING CHERENKOV COUNTER* Sherman,"'"'' R. C. W e b b , ' ' ' " ' ' " ' " M. ^.otov-~ S C i i v ^ ^ - - ^ - ^ Cester, V. L. Fitch, A. Montag, S. Sherman, R. C. Webb, M. S. Witherell Department of Physics, Princeton University, Princeton, N. J. 085A4 Abstract The field of ring imaging (broad band differential) Cherenkov detectors-^ has become a very active area of interest in detector development at several high energy physics laboratories. Our group has previously report- ed2 on a method of Cherenkov ring imaging for a counter with large momentum and angular acceptance using stan- dard photo multipliers. Recently, we have applied this technique to the design of a set of Cherenkov counters

198

U.S., China Partner to Counter Nuclear Smuggling | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Partner to Counter Nuclear Smuggling Partner to Counter Nuclear Smuggling U.S., China Partner to Counter Nuclear Smuggling January 19, 2011 - 12:00am Addthis WASHINGTON D.C. - The Department of Energy's National Nuclear Security Administration (NNSA) today announced the signing of a memorandum of understanding (MOU) with China that paves the way for the establishment of a radiation detection training center in Qinhuangdao, China. Deputy Secretary of Energy Daniel Poneman and Vice Minister SUN Yibiao of the General Administration of China Customs signed the MOU in a ceremony at DOE headquarters in Washington. The signed comes as part of Chinese President Hu Jintao's state visit to Washington, DC. "This agreement represents the shared commitment of both the United States and China to enhance global peace and security by working to prevent

199

The counting of naturally occuring radiocarbon in the form of benzene in a liquid scintillation counter  

Science Journals Connector (OSTI)

A counting system is described for C14 dating with a benzene scintillator solution. The single photomultiplier counter used is relatively simple and reliable. Different sizes and forms of the counting solution containers were investigated. A 6 ml cell with a background of 4?0 counts/min and a 45 per cent detection efficiency is recommended for routine C14 dating. A 60 ml cell with a background of 14?6 counts/min and a 45 per cent detection efficiency is capable of dating samples as old as 57,500 years (4 ? statistics, 48 hr counting). The calibration and operation of the counter is discussed. On comparison with standard gas counter methods, it is suggested that routine C14 dating by the benzene method is preferable in those cases where the laboratory personnel are more skilled in chemical manipulations than electronic technique.

C. Leger; M.A. Tamers

1963-01-01T23:59:59.000Z

200

Characterization and performance evaluation of a new passive neutron albedo reactivity counter for safeguards measurements  

Science Journals Connector (OSTI)

Abstract A prototype 3He-based Passive Neutron Albedo Reactivity (PNAR) counter was developed and tested at Los Alamos National Laboratory (LANL) in collaboration with the Korea Atomic Energy Research Institute (KAERI) to measure the fissile content in electrochemical recycling (ER) product materials. The counter consists of 16 3He cylindrical gas-filled proportional counters at 4 atm of pressure embedded in high-density polyethylene. In this work, experimental measurements were performed at LANL to characterize the performance of the PNAR counter using surrogate materials for the uranium metal ingot. The purpose of these experiments was to: 1) measure the operating and calibration parameters of the PNAR counter (e.g. efficiency profiles, coincidence gate fractions, die-away time) and 2) evaluate the accuracy and sensitivity of the PNAR method and the time correlated induced fission (TCIF) method for quantifying the 235U mass in PWR fresh LEU fuel rods and Materials Testing Reactor (MTR) HEU fuel plates. A small 244Cm reference source (13,373 n/s) was placed in the center of the fuel rods and fuel plates to simulate spontaneous fission from sub-ppm (parts per million) levels of Cm contamination in the U ingot. In order to compare the relative accuracy of the PNAR and TCIF methods for quantifying 235U mass, calibration curves were generated for the net doubles rate and the doubles Cd ratio using the Deming software. The results from this experiment will be used to obtain a better understanding of the sensitivity of the PNAR and TCIF methods for samples with low neutron multiplication. Furthermore, this experimental measurement data will also help inform safeguards research and development (R&D) efforts on the viability of nondestructive assay (NDA) techniques and detector designs for quantifying fissile content in ER product materials. Future work will include performing measurements with the PNAR counter on small samples of U/TRU materials.

Adrienne M. LaFleur; Seong-Kyu Ahn; Howard O. Menlove; Michael C. Browne; Ho-Dong Kim

2014-01-01T23:59:59.000Z

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201

Conducting polymers based counter electrodes for dye-sensitized solar cells  

SciTech Connect

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

202

Testing a Cloud Condensation Nuclei Remote Sensing Method  

NLE Websites -- All DOE Office Websites (Extended Search)

a Cloud Condensation Nuclei a Cloud Condensation Nuclei Remote Sensing Method S. J. Ghan Climate Physics Pacific Northwest National Laboratory Richland, Washington D. R. Collin Department of Atmospheric Sciences Texas A&M University College Station, Texas Introduction Under certain conditions vertical profiles of cloud condensation nuclei (CCN) spectra can be retrieved from ground-based measurements (Ghan and Collins 2003). Surface measurements of the CCN spectrum are scaled by the ratio of the 180 backscatter (or extinction) profile to the surface backscatter (or extinction). The backscatter (or extinction) profile is measured by Raman lidar (RL), and is corrected to dry conditions using the vertical profile of relative humidity (calculated from the absolute

203

Super Heavy Nuclei over Critical Fields and their Conections  

SciTech Connect

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

204

Spontaneous-fission half-lives of deformed superheavy nuclei  

Science Journals Connector (OSTI)

Spontaneous-fission half-lives of the heaviest nuclei are analyzed in a multidimensional deformation space. They are calculated in a dynamical approach, without any adjustable parameters. The potential energy is obtained by the macroscopic-microscopic method and the inertia tensor by the cranking method. The action integral is minimized by a variational procedure. Even-even nuclei with proton number Z=104–114 and neutron number N=142–176 are considered. The results reproduce existing experimental data rather well. Relatively long half-lives are predicted for many unknown nuclei, sufficient to detect them if synthesized in a laboratory.

R. Smola?czuk; J. Skalski; A. Sobiczewski

1995-10-01T23:59:59.000Z

205

Theory of deep-inelastic scattering from light nuclei  

Science Journals Connector (OSTI)

We present a theory of deep-inelastic scattering from light nuclei that may be formulated in the target rest frame. (In our approach we can avoid the ambiguities that arise when boosting wave functions of light nuclei to an infinite momentum frame.) The resulting theory is applicable at relatively low values of momentum transfer and allows for a systematic treatment of off-mass-shell effects. We calculate the asymmetry in polarized leptoproduction from polarized H2 and He3 targets and also provide expressions for the spin-independent and spin-dependent structure functions of these nuclei.

L. S. Celenza; A. Pantziris; C. M. Shakin

1990-05-01T23:59:59.000Z

206

Search milli-charged particles at SLAC  

SciTech Connect

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

207

Shell-Structure and Pairing Interaction in Superheavy Nuclei: Rotational Properties of the Z=104 Nucleus Rf256  

Science Journals Connector (OSTI)

The rotational band structure of the Z=104 nucleus Rf256 has been observed up to a tentative spin of 20? using state-of-the-art ?-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.

P. T. Greenlees et al.

2012-07-03T23:59:59.000Z

208

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

209

Electromagnetic Studies of Mesons, Nucleons, and Nuclei  

SciTech Connect

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

210

Nuclear structure/nuclei far from stability  

SciTech Connect

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

211

THEORETICAL STUDIES OF HADRONS AND NUCLEI  

SciTech Connect

This report details final research results obtained during the 9 year period from June 1, 1997 through July 15, 2006. The research project, entitled �Theoretical Studies of Hadrons and Nuclei�, was supported by grant DE-FG02-97ER41048 between North Carolina State University [NCSU] and the U. S. Department of Energy [DOE]. In compliance with grant requirements the Principal Investigator [PI], Professor Stephen R. Cotanch, conducted a theoretical research program investigating hadrons and nuclei and devoted to this program 50% of his time during the academic year and 100% of his time in the summer. Highlights of new, significant research results are briefly summarized in the following three sections corresponding to the respective sub-programs of this project (hadron structure, probing hadrons and hadron systems electromagnetically, and many-body studies). Recent progress is also discussed in a recent renewal/supplemental grant proposal submitted to DOE. Finally, full detailed descriptions of completed work can be found in the publications listed at the end of this report.

STEPHEN R COTANCH

2007-03-20T23:59:59.000Z

212

Production and propagation of mesons in complex nuclei  

SciTech Connect

The propagation of unstable mesons in nuclei is considered with regard to the use of the nucleus as a micro-laboratory. Specific problems considered are those of the nu and the S*/delta systems. 17 refs., 12 figs.

Gibbs, W.R.; Kaufmann, W.B.

1987-01-01T23:59:59.000Z

213

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

214

Description of isoscalar giant dipole resonance in nuclei  

E-Print Network (OSTI)

collective and microscopic transition densities. Possible underestimations of the energy weighted sum rule for the case of the ISGDR are reported. An alternative description for the ISGDR in nuclei based on the Fermi liquid drop model (FLDM...

Pochivalov, Oleksiy Grigorievich

2009-05-15T23:59:59.000Z

215

Preformation factor for ? particles in isotopes near N=Z  

Science Journals Connector (OSTI)

Combining the experimental ?-decay energies and half-lives, the ?-particle preformation factors for the nuclei around N=Z=50 are extracted within the generalized liquid drop model. It is found that the average order of magnitude of the preformation factor is 1.0×10?1. In addition, a detailed discussion on the odd-even effect of the preformation factor is performed.

Y. Z. Wang; J. Z. Gu; Z. Y. Hou

2014-04-02T23:59:59.000Z

216

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

217

The Production and Study of Neutron-rich Nuclei  

SciTech Connect

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

218

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

2014-06-12T23:59:59.000Z

219

Nitrogen-doped graphene as transparent counter electrode for efficient dye-sensitized solar cells  

SciTech Connect

Graphical abstract: Display Omitted Highlights: ? NG sheets are prepared through a hydrothermal reduction of graphite oxide. ? The transparent NG counter electrodes of DSCs are fabricated at room temperature. ? Transparent NG electrode exhibits excellent catalytic activity for the reduction of I{sub 3}{sup ?}. ? The DSC with NG electrode achieves a comparable efficiency to that of the Pt-based cell. ? The efficiency of rear illumination is about 85% that of front illumination. -- Abstract: Nitrogen-doped graphene sheets are prepared through a hydrothermal reduction of graphite oxide in the presence of ammonia and applied to fabricate the transparent counter electrode of dye-sensitized solar cells. The atomic percentage of nitrogen in doped graphene sample is about 2.5%, and the nitrogen bonds display pyridine and pyrrole-like configurations. Cyclic voltammetry studies demonstrate a much higher electrocatalytic activity toward I{sup ?}/I{sub 3}{sup ?} redox reaction for nitrogen-doped graphene, as compared with pristine graphene. The dye-sensitized solar cell with this transparent nitrogen-doped graphene counter electrode shows conversion efficiencies of 6.12% and 5.23% corresponding to front-side and rear-side illumination, respectively. Meanwhile, the cell with a Pt counter electrode shows a conversion efficiency of 6.97% under the same experimental condition. These promising results highlight the potential application of nitrogen-doped graphene in cost-effective, transparent dye-sensitized solar cells.

Wang, Guiqiang, E-mail: wgqiang123@163.com [School of Chemical Engineering, Shandong University of Technology, Zibo 255049 (China)] [School of Chemical Engineering, Shandong University of Technology, Zibo 255049 (China); Fang, Yanyan; Lin, Yuan [Institute of Chemistry, Chinese Academy of Science, Beijing 100080 (China)] [Institute of Chemistry, Chinese Academy of Science, Beijing 100080 (China); Xing, Wei; Zhuo, Shuping [School of Chemical Engineering, Shandong University of Technology, Zibo 255049 (China)] [School of Chemical Engineering, Shandong University of Technology, Zibo 255049 (China)

2012-12-15T23:59:59.000Z

220

Virtual monotonic counters and count-limited objects using a TPM without a trusted OS  

Science Journals Connector (OSTI)

A trusted monotonic counter is a valuable primitive that enables a wide variety of highly scalable offline and decentralized applications that would otherwise be prone to replay attacks, including offline payment, e-wallets, virtual trusted storage, ... Keywords: certified execution, e-wallet memory integrity checking, key delegation, stored-value, trusted storage

Luis F. G. Sarmenta; Marten van Dijk; Charles W. O'Donnell; Jonathan Rhodes; Srinivas Devadas

2006-11-01T23:59:59.000Z

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.


221

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

222

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

223

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

E-Print Network (OSTI)

Tri-Met's Experience With Automatic Passenger Counter and Automatic Vehicle Location Systems James includes Automatic Vehicle Location (AVL) using a satellite-based global positioning system (GPS); · Voice for temporary data storage, a vehicle control head displaying schedule adherence to operators, detection

Bertini, Robert L.

224

Statistics of counter-streaming solar wind suprathermal electrons at solar minimum: STEREO observations  

E-Print Network (OSTI)

1 Statistics of counter-streaming solar wind suprathermal electrons at solar minimum: STEREO, University of New Brunswick, Fredericton, Canada 6 Space Sciences Laboratory, University of California University of New Hampshire, Durham, USA Abstract. Previous work has shown that solar wind suprathermal

Paris-Sud XI, Université de

225

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

226

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

2014-04-19T23:59:59.000Z

227

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

228

Extending the Use of Evacuation Simulators to Support Counter Terrorism: Using Models of Human Behaviour to Coordinate Emergency Responses to Improvised Explosive Devices  

E-Print Network (OSTI)

Extending the Use of Evacuation Simulators to Support Counter Terrorism: Using Models of Human; evacuation; security; counter terrorism Abstract Software simulations have been widely used to model the risk assessments that drive counter terrorism. Two key areas are discussed; changes in the human

Johnson, Chris

229

Thermal quasiparticle correlations and continuum coupling in nuclei far from stability  

Science Journals Connector (OSTI)

The contributions of quasiparticle correlations and of continuum coupling upon the superfluid properties of neutron-rich Ni isotopes are studied within the modified BCS (MBCS) approximation at finite temperature. The effect of quasiparticle correlations is included using a secondary Bogoliubov-type canonical transformation explicitly involving the quasiparticle occupation numbers at temperature T. The effect of continuum coupling is taken into account via the finite widths of the resonant states. It is shown that the combined effect of thermal quasiparticle correlations and of continuum coupling washes out the sharp superfluid-normal phase transition given by the standard finite-temperature BCS calculations. Within the proposed resonant-continuum MBCS approximation the fluctuations of particle number also become more suppressed especially at high temperature for nuclei closer to the drip line. Finally, it is found within the same approximation that the two-neutron separation energy for 84Ni drops to zero at T?0.8 MeV.

N. Dinh Dang and A. Arima

2003-01-16T23:59:59.000Z

230

Neutron-neutron correlation in the halo dissociation of light exotic nuclei  

Science Journals Connector (OSTI)

We present model results for the two-halo-neutron correlation functions, Cnn, for the dissociation process of light exotic nuclei modelled as two neutrons and a core. A minimum is predicted for Cnn as a function of the relative momentum of the two neutrons, pnn, due to the coherence of the neutrons in the halo and final state interaction. Studying the systems Be14, Li11, and He6 within this model, we show that the numerical asymptotic limit, Cnn?1, occurs only for pnn?400MeV/c, while such limit is reached for much lower values of pnn in an independent particle model as the one used in the analysis of recent experimental data. Our model is consistent with data once the experimental correlation function is appropriately normalized.

M. T. Yamashita; T. Frederico; Lauro Tomio

2005-07-18T23:59:59.000Z

231

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

232

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

233

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

234

Single-phonon and multi-phonon excitations of the $?$ vibration in rotating odd-$A$ nuclei  

E-Print Network (OSTI)

Multi-phonon excitations in atomic nuclei were observed very rarely although collective motions in quantum many-body systems are described as bosonic excitations. In particular, the first two-phonon $\\gamma$ vibrational ($2\\gamma$) excitation in odd-$A$ nuclei was reported in 2006 and only a few have been known. Quite recently, conspicuously enhanced $B(E2)$s feeding $2\\gamma$ states were observed in $^{105}$Nb and conjectured that their parent states are candidates of $3\\gamma$ states. In the present work, the model space is enlarged from the present author's previous calculation for $^{103}$Nb. The purpose is twofold: One is to see how the description of $2\\gamma$ states is improved, and the other is to examine the existence of collective $3\\gamma$ states, and when they exist, study their collectivity through calculating interband $B(E2)$s. The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. Interband $B(E2)$s are calculated by adopting the method of the generalized intensity relation. The present calculation reproduces the observed spectra of $0\\gamma$ - $2\\gamma$ states well and gives collective $3\\gamma$ states with enhanced $B(E2)$s to $2\\gamma$ states in $^{103}$Nb and $^{105}$Nb. The most collective $3\\gamma$ state with the highest $K$ at zero rotation is thought to be the main component of the observed band.

Masayuki Matsuzaki

2014-06-13T23:59:59.000Z

235

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

236

Nuclear and Particle Futures  

NLE Websites -- All DOE Office Websites (Extended Search)

Nuclear and Particle Futures Nuclear and Particle Futures The Lab's four Science Pillars harness capabilities for solutions to threats- on national and global scales. Contacts...

237

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

SciTech Connect

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

238

Reporting Prescription Drugs, Over-the-Counter Medications, and Dietary Supplements (ORISE 08-NSEM-0227, 2008)  

NLE Websites -- All DOE Office Websites (Extended Search)

Reporting Reporting Prescription Drugs, Over-the-Counter Medications, and Dietary Supplements Human Reliability Program U.S. Department of Energy Office of Health, Safety and Security Office of Departmental Personnel Security Contents of this brochure are based on 10 CFR Part 712, Human Reliability Program; however, the information presented herein in no way supersedes or has precedence over the provisions of that regulation as published or amended. Table of contents Introduction.......................................................................................................................................1 Prescription drugs .............................................................................................................................1

239

COUNTER PROPAGATION OF ELECTRON AND CO2 LASER BEAMS IN A PLASMA CHANNEL.  

SciTech Connect

A high-energy CO{sub 2} laser is channeled in a capillary discharge. Occurrence of guiding conditions at a relatively low plasma density (<10{sup 18} cm{sup -3}) is confirmed by MHD simulations. Divergence of relativistic electron beam changes depending on the plasma density. Counter-propagation of the electron and laser beams inside the plasma channel results in intense x-ray generation.

HIROSE,T.; POGORELSKY,I.V.; BEN ZVI,I.; YAKIMENKO,V.; KUSCHE,K.; SIDDONS,P.; KUMITA,T.; KAMIYA,Y.; ZIGLER,A.; GREENBERG,B.; ET AL

2002-11-12T23:59:59.000Z

240

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

E-Print Network (OSTI)

?Countering the Master Narrative: Muslims and Islam in Science Fiction, Fantasy and Comics.? Rebecca Hankins Science Fiction Symposium-April 15, 2010 The influence that science fiction, fantasy and comic literature has and continues to have... Nights to the time-travel stories of the 19th century Egyptian, al-Muwaylihi, to the obvious borrowing of Islamic themes by contemporary writers, movie scripts, and music. Rebecca Carol Johnson, Richard Maxwell, and Katie Trumpener?s article, The Arabian...

Hankins, Rebecca; Hankins, Rebecca

2010-04-15T23:59:59.000Z

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.


241

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

E-Print Network (OSTI)

?Countering the Master Narrative: Muslims and Islam in Science Fiction, Fantasy and Comics.? Rebecca Hankins Science Fiction Symposium-April 15, 2010 The influence that science fiction, fantasy and comic literature has and continues to have... Nights to the time-travel stories of the 19th century Egyptian, al-Muwaylihi, to the obvious borrowing of Islamic themes by contemporary writers, movie scripts, and music. Rebecca Carol Johnson, Richard Maxwell, and Katie Trumpener?s article, The Arabian...

Hankins, Rebecca

2010-08-16T23:59:59.000Z

242

Design and Operating Characteristics of a Lead-lined Hexagonal Neutron-Multiplicity Counter  

SciTech Connect

A high-efficiency Hexagonal Neutron-Multiplicity Counter (HNMC) has been developed for measurement of non-contact handleable power plant decommissioning and dismantling wastes. The HNMC counter was originally designed for nuclear stockpile safeguards measurements, but the unique challenges of the present application required significant adaptations to the design. The counter consists of six detector modules, each containing two parallel rows of 11 He-3 tubes embedded in high-density polyethylene and arranged in a hexagonal pattern around a central cavity. Graphite reflectors are located above and below the cavity to improve the axial linearity of the response and increase the overall efficiency, which is measured to be 39% for a centrally located Cf-252 source. The HNMC also includes an add-a-source feature by which a known Cf-252 source can be introduced near the bottom of the cavity. The perturbation of the count rate due to the Cf-252 is used to estimate the efficiency loss due to the moderator content of the drum matrix. Unusual to similar large volume multiplicity counters is the addition of a 6.4 mm lead lining on the inner walls of the cavity. This addition results in a suitably low value for the minimum detectable Pu-240-effective mass in drums with as much as 10 mSv.h{sup -1} gamma-ray dose rates when operated in a properly shielded bunker to suppress the background production of neutrons in the lead by cosmic rays. The details of the design and operating characteristics of the HNMC are presented and discussed. (authors)

Mueller, W.F.; Croft, S.; McElroy, R.D.; Venkataraman, R.; Zhu, H. [Canberra Industries, Inc., 800 Research Parkway, Meriden, Connecticut 06450 (United States)

2006-07-01T23:59:59.000Z

243

Testing a Cloud Condensation Nuclei Remote Sensing Method  

NLE Websites -- All DOE Office Websites (Extended Search)

a Cloud Condensation Nuclei a Cloud Condensation Nuclei Remote Sensing Method S. J. Ghan Climate Dynamics Group Pacific Northwest National Laboratory Richland, Washington Introduction Under certain conditions vertical profiles of cloud condensation nuclei (CCN) spectra can be retrieved from ground-based measurements. Surface measurements of the CCN spectrum are scaled by the ratio of the backscatter (or extinction) profile to the surface backscatter (or extinction). The backscatter (or extinction) profile is measured by Raman lidar, and is corrected to dry conditions using the vertical profile of relative humidity (also measured by Raman Lidar) and surface measurements of the dependence of backscatter (or extinction) on relative humidity. This method should be accurate up to

244

Shell model Monte Carlo investigation of rare earth nuclei  

Science Journals Connector (OSTI)

We utilize the shell model Monte Carlo method to study the structure of rare earth nuclei. This work demonstrates the first systematic full oscillator shell with intruder calculations in such heavy nuclei. Exact solutions of a pairing plus quadrupole Hamiltonian are compared with the static path approximation in several dysprosium isotopes from A=152 to 162, including the odd mass A=153. Some comparisons are also made with Hartree-Fock-Bogoliubov results from Baranger and Kumar. Basic properties of these nuclei at various temperatures and spin are explored. These include energy, deformation, moments of inertia, pairing channel strengths, band crossing, and evolution of shell model occupation numbers. Exact level densities are also calculated and, in the case of 162Dy, compared with experimental data.

J. A. White; S. E. Koonin; D. J. Dean

2000-02-14T23:59:59.000Z

245

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

246

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

247

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

248

Development of Gas Proportional Scintillation Counter for Light Heavy-Ion Detection  

SciTech Connect

In recent years, nuclear data have been needed in the medical field. Nuclear data induced by light heavy ions are especially needed at high precision for cancer treatment, although there are not enough usable data at present.We have a plan to measure light heavy-ion nuclear data with a dE-E detector. Low density is needed for the dE detector. We have two options for the dE detector: a semiconductor detector (SSD) and a Gas Counter. On one hand, SSD has good energy resolution, but on the other hand, it is expensive and its decay time is on the 100-microsecond order. A Gas Counter is inexpensive, and a Gas Proportional Scintillation Counter (GPSC) has fast decay time. Then, we developed a GPSC for the dE detector, and its evaluation experiment was carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC).We will report the results of the experiment with the performance of the GPSC.

Hohara, Sin-ya; Imamura, Minoru; Kin, Tadahiro; Yamashita, Yusuke; Maki, Daiske; Saiho, Fuminobu; Ikeda, Katsuhiko; Uozumi, Yusuke; Matoba, Masaru [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka 812-8581 (Japan)

2005-05-24T23:59:59.000Z

249

CSER-98-009: antech neutron multiplicity counter for nondestructive analysis  

SciTech Connect

The ANTECH neutron multiplicity counter is a portable nondestructive assay (NDA) instrument which measures plutonium content by counting fission neutrons in the presence of (a,n) neutrons. Neutrons from the (a,n) process are discriminated against through the use of coincidence counting. The instrument will be used for the purpose of determining inventory of plutonium in the Plutonium Finishing Plant (PFP). The portability of the instrument will facilitate this task by minimizing the necessity of transporting fissile material. The use of the Antech counter is approved based on the inherent safety of the containers to be assayed in that an acceptable margin of subcriticality has been demonstrated for all normal and credible abnormal conditions in accordance with HNF-PRO-537 (F, 1997). A summary of the results of the abnormal conditions are tabulated in Table 2. For foreseeable contingencies, the calculated k{sub eff}s are less than 0.95 after taking into account the calculational bias and statistical uncertainty equal to or larger than the 95% confidence level. This approval is based on the requirement that only one container is to be put in the counter at a time and in accordance with the other limits listed in section 1.4. The design of the current instrument conforms with the acceptability criteria which allow the other NDA detectors currently employed at the facility to be safely used.

GOLDBERG, H.J.

1999-05-12T23:59:59.000Z

250

Side-by-Side Comparison of Particle Count and Mass Concentration  

NLE Websites -- All DOE Office Websites (Extended Search)

Side-by-Side Comparison of Particle Count and Mass Concentration Side-by-Side Comparison of Particle Count and Mass Concentration Measurements in a Residence Title Side-by-Side Comparison of Particle Count and Mass Concentration Measurements in a Residence Publication Type Report Year of Publication 2011 Authors Chan, Wanyu R., and Federico Noris Publisher Lawrence Berkeley National Laboratory City Berkeley Keywords energy analysis and environmental impacts department Abstract Particulate matter (PM) is a contaminant of concern in many indoor environments, including residential and commercial buildings. Health guidelines for exposure to particles are in units of mass concentrations. Relative to time-integrated mass measurements collected on filters, real-time particle counters are less time-consuming to operate. Studies found reasonable correlation between these two measurement techniques, but agreement may vary in different sampling environments, and depends on the instruments used. We performed a side-by-side comparison of particle counts and mass concentrations estimated by three types of real-time instruments: MetOne BT-637 optical particle counter (OPC), TSI DustTrak aerosol monitor, and TSI aerodynamic particle sizer (APS) spectrometer. In addition to these real-time instruments, time-integrated particle mass was also collected using PM2.5 and PM10 Personal Environmental Monitors (PEMs) manufactured by SKC. Sampling was conducted for two consecutive days in an occupied single-family house in Berkeley, California. Concentration profiles had similar trends, with DustTraks reporting higher particle mass concentrations, partially explained by the density value assumed in the calibration. We made assumptions for particle size and density to calculate the PM2.5 and PM10 mass concentrations for the MetOne and APS, and compared with the filter-based measurements. Despite uncertainties and assumptions, there was generally good agreement for the different methods.

251

Nuclear Fusion for Bose Nuclei Confined in Ion Traps  

SciTech Connect

Nuclear fusion of integer spin nuclei confined in an isotropic ion trap is investigated. Solutions of the ground state for charged bosons trapped in the isotropic harmonic oscillator potential are calculated using the equivalent linear two-body method for many-body problems, which is based on an approximate reduction of the many-body Schroedinger equation by the use of a variational principle. Using the ground-state wave function, theoretical estimates of probabilities and rates for nuclear fusion for Bose nuclei confined in ion traps are obtained. Numerical estimates for fusion rates are presented for the case of deuteron-deuteron fusion.

Kim, Yeong E.; Zubarev, Alexander L. [Purdue University (United States)

2000-03-15T23:59:59.000Z

252

JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei  

SciTech Connect

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

253

Spontaneous Onion-Structure Formation from Planar Lamellar Nuclei  

Science Journals Connector (OSTI)

Nucleation and growth are a basic elementary process of ordering. The nucleation process is controlled by a competition between interfacial and bulk energy. Thus an ordered structure of a nucleus at its birth is not necessarily the most stable thermodynamically: Ostwald step rule. In addition to this, we found the topological transformation of nuclei from the most stable bulk structure (planar lamella) to a metastable one (onion) in a lyotropic liquid crystal. This indicates that the fate of nuclei of low-dimensional internal order can also be seriously affected by an additional competition between interfacial and elastic deformation energy.

Yasutaka Iwashita and Hajime Tanaka

2007-04-06T23:59:59.000Z

254

Proton capture resonance spins by multidimensional scaling: fp nuclei  

Science Journals Connector (OSTI)

The method of nonmetric multidimensional scaling has been used to attribute spins to a large number of proton capture resonances in five fp-shell nuclei, V47, Mn51, Mn53, Co55, and Cu61, using as input information only the gamma decay branching ratios. The calibration of the method relies on the measured spins of a number of the resonances. In more than half the cases, a unique spin is found. The results of the analysis allow a reappraisal of analog states in the five nuclei.

J. A. Cameron

1993-06-01T23:59:59.000Z

255

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

256

The Effect of Counter Ions on the Conformation of Intrinsically Disordered Proteins Studied by Size-Exclusion Chromatography  

Science Journals Connector (OSTI)

Counter ions are able to change the conformation of intrinsically disordered proteins (IDPs) to a more compact structure ... radius, which describes the hydrodynamic properties of protein molecules. In our paper ...

Magdalena Wojtas; Tomasz M. Kap?on…

2012-01-01T23:59:59.000Z

257

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

E-Print Network (OSTI)

of the reactor, radioactive material storage, and potential for contamination, the possibilities were reduced to the Lecture and Conference Room. In deciding between the two, two factors prevailed: structural strength and ease of moving the counter...

Baca, Bernadette Doris

2012-06-07T23:59:59.000Z

258

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

SciTech Connect

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

259

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

260

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

NLE Websites -- All DOE Office Websites (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....

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

Atmospheric sulphur and cloud condensation nuclei in marine air in the Southern Hemisphere  

Science Journals Connector (OSTI)

...that control cloud depth, solar radiation and drizzle. Profound...condensation nuclei, drizzle, and solar radiation, on marine stratocumulus...pp. 185195. Norwell, Massachusetts: Kluwer Academic. Yin, F...condensation nuclei, drizzle, and solar radiation, on marine stratocumulus...

1997-01-01T23:59:59.000Z

262

Electric dipole moments of light nuclei from {chi}EFT  

SciTech Connect

I present recent calculations of EDMs of light nuclei using chiral effective field theory techniques. At leading-order, we argue that they can be expressed in terms of six CP-violating low-energy constants. With our expressions, eventual non-zero measurements of EDMs of deuteron, helion, and triton can be combined to disentangle the different sources of CP-violation.

Higa, Renato [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05314-970, Sao Paulo, SP (Brazil)

2013-03-25T23:59:59.000Z

263

Binary Black Hole Accretion Flows in Merged Galactic Nuclei  

Science Journals Connector (OSTI)

......for Theoretical Physics, Oiwake-cho...when the gas can pass across the maximum...mass-capture rates are eventually...holes|black hole physics|galaxies: nuclei...when the gas can pass across the maximum...mass-capture rates exhibit little...for Theoretical Physics (YITP) of Kyoto......

Kimitake Hayasaki; Shin Mineshige; Hiroshi Sudou

2007-04-25T23:59:59.000Z

264

Thermal Neutron Capture for Nuclei A = 3 - 20  

NLE Websites -- All DOE Office Websites (Extended Search)

Thermal Neutron Capture Evaluated Data for Nuclei A 3 - 20 Go to the Text Only below if you prefer to view the nuclides in a text list. 19Ne 20Ne 18F 19F 20F 15O 16O 17O 18O 19O...

265

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

266

Trends in the study of light proton rich nuclei  

SciTech Connect

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

267

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

268

Band structure of doubly-odd nuclei around mass 130  

SciTech Connect

Nuclear structure of the doublet bands in the doubly-odd nuclei with mass A{approx}130 is studied in terms of a pair-truncated shell model. The model reproduces quite well the energy levels of the doublet bands and the electromagnetic transitions. The analysis of the electromagnetic transitions reveals new band structure of the doublet bands.

Higashiyama, Koji [Department of Physics, Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan); Yoshinaga, Naotaka [Department of Physics, Saitama University, Saitama City 338-8570 (Japan)

2011-05-06T23:59:59.000Z

269

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

270

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

271

Particle Physics Education Sites  

NLE Websites -- All DOE Office Websites (Extended Search)

쭺-¶ 쭺-¶ Particle Physics Education Sites ¡]¥H¤U¬°¥~¤åºô¯¸¡^ quick reference Education and Information - National Laboratory Education Programs - Women and Minorities in Physics - Other Physics Sites - Physics Alliance - Accelerators at National Laboratories icon Particle Physics Education and Information sites: top Introduction: The Particle Adventure - an interactive tour of particle physics for everyone: the basics of theory and experiment. Virtual Visitor Center of the Stanford Linear Accelerator Center. Guided Tour of Fermilab, - overviews of several aspects of Particle Physics. Also check out Particle Physics concepts. Probing Particles - a comprehensive and straight-forward introduction to particle physics. Big Bang Science - approaches particle physics starting from the theoretical origin of the universe.

272

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

273

Energy Density Functional for Nuclei and Neutron Stars  

SciTech Connect

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

274

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

275

Dynamic-angle spinning and double rotation of quadrupolar nuclei  

SciTech Connect

Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids.

Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)

1991-07-01T23:59:59.000Z

276

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

277

Communication Coherence transfer between spy nuclei and nitrogen-14 in solids  

E-Print Network (OSTI)

Communication Coherence transfer between spy nuclei and nitrogen-14 in solids Simone Cavadini a Coherence transfer from `spy nuclei' such as 1 H or 13 C (S = 1/2) was used to excite single- or double-quantum coherences of 14 N nuclei (I = 1) while the S spins were aligned along the static field, in the manner

278

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

279

Review of Particle Properties Particle Data Group  

Science Journals Connector (OSTI)

This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group (Phys. Letters 39B, No. 1 (1972)). Data are evaluated, listed, averaged, and summarized in tables. A data booklet is also available.

THOMAS A. LASINSKI; ANGELA BARBARO-GALTIERI; ROBERT L. KELLY; ALAN RITTENBERG; ARTHUR H. ROSENFELD; THOMAS G. TRIPPE; NAOMI BARASH-SCHMIDT; CLAUDE BRICMAN; VLADIMIR CHALOUPKA; PAUL SÖDING; MATTS ROOS

1973-04-01T23:59:59.000Z

280

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

SciTech Connect

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

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

2012-07-01T23:59:59.000Z

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.


281

Over the Counter but No Longer under the Radar — Pediatric Cough and Cold Medications  

Science Journals Connector (OSTI)

...have not been established." In 2006, the American College of Chest Physicians found that "literature regarding over-the-counter cough medications does not support the efficacy of such products in the pediatric age group." Meanwhile, poison-control centers have reported more than 750,000 calls of concern... Dr. Joshua Sharfstein, Marisa North, and Dr. Janet Serwint write that, in October, an FDA advisory committee voted in favor of immediate action against the use of cough and cold medications in children under 6. After the meeting, the major manufacturers ...

Sharfstein J.M.North M.Serwint J.R.

2007-12-06T23:59:59.000Z

282

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

SciTech Connect

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

Littfin, K.M.

1992-09-01T23:59:59.000Z

283

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

284

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

285

Near-yrast structure of N=93 neutron-rich lanthanide nuclei  

Science Journals Connector (OSTI)

Two neutron-rich N=93 isotones, Sm155 and Nd153, have been studied by delayed ?-ray and conversion-electron spectroscopy at the Lohengrin mass spectrometer. A half-life of 2.9(5) ?s has been measured for the ?5/2+[642] state at 16.5 keV in Sm155. The decay of a 1.17(7)-?s isomer in Nd153, at 191.7 keV, has been remeasured and its spin has been reassigned as (5/2)+. This state contains a strong component of the ?5/2+[642] Nilsson orbital. In addition, a new 1.00(8)-?s isomeric state at 538.6 keV, with a probable ?11/2-[505] Nilsson configuration, has been observed in Sm155. Triple ?-ray coincidence data from the spontaneous fission of a Cf252 source placed inside the Gammasphere array were used to extend the collective band on top of the (5/2+) isomeric state of Nd153, and a new band with the same bandhead spin has been observed in Ce151. The observation of this new band and an additional new transition in the ground-state band has led us to change the ground-state spin of Ce151 to (3/2-). Calculations using the quasiparticle-rotor model successfully reproduce the majority of the features of the ? decays of these nuclei, including branching ratios and isomeric half-lives. Because this model uses a reflection-symmetric core, we conclude that the polarizing effect of the odd particle is responsible for the dipole moment present in the ?5/2+[642] states of the three nuclei studied and the ?11/2-[505] level of Sm155.

G. S. Simpson; W. Urban; J. A. Pinston; J. C. Angelique; I. Deloncle; H. R. Faust; J. Genevey; U. Köster; T. Materna; R. Orlandi; A. Scherillo; A. G. Smith; J. F. Smith; T. Rz?ca-Urban; I. Ahmad; J. P. Greene

2010-02-16T23:59:59.000Z

286

Particle and Size Distribution  

Science Journals Connector (OSTI)

The long and short sides were called directional tangential cutting edge or random diameter. When the number of measured particles was large enough, results could reflect the average cross section of particle sam...

Zhonglin Xu

2014-01-01T23:59:59.000Z

287

Review of particle properties  

Science Journals Connector (OSTI)

This review of the properties of leptons, mesons, and baryons is an updating of the Review of Particle Properties, Particle Data Group [Phys. Lett. 111B (1982)]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available.

C. G. Wohl; R. N. Cahn; A. Rittenberg; T. G. Trippe; G. P. Yost; F. C. Porter; J. J. Hernandez; L. Montanet; R. E. Hendrick; R. L. Crawford; M. Roos; N. A. Törnqvist; G. Höhler; M. Aguilar-Benitez; T. Shimada; M. J. Losty; G. P. Gopal; Ch. Walck; R. E. Shrock; R. Frosch; L. D. Roper; W. P. Trower; B. Armstrong (Particle Data Group)

1984-04-01T23:59:59.000Z

288

Classifying Airborne Particles  

Science Journals Connector (OSTI)

Considering the selective Rayleigh light scattering behaviour by small particles, this study adopts a new technique to classify nano-scale airborne particles with colour histogram features. Noise was generated using scattered light by five different ... Keywords: Particle classification, Rayleigh scattering, noise histogram, histogram maximum value index

Kapila K. Pahalawatta; Richard Green

2011-12-01T23:59:59.000Z

289

Composition of the September 2, 1966 solar particle event1 NASA/Goddard Space Flight Center, G~zenbelt,Maryland  

E-Print Network (OSTI)

, Canada to study the composition and the characteristics of the September 2, 1966 solar flare event. ThcseComposition of the September 2, 1966 solar particle event1 NASA/Goddard Space Flight Center, G to study all the components, namely, the singly, doubly, ancl multiply charged nuclei emitted in the solar

Reames, Donald V.

290

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

SciTech Connect

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

291

Role of shapes in the identification of superheavy nuclei  

SciTech Connect

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

292

Magnetic Moments of Light Nuclei from Lattice Quantum Chromodynamics  

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

293

Interacting boson models for N{approx}Z nuclei  

SciTech Connect

This contribution discusses the use of boson models in the description of N{approx}Z nuclei. A brief review is given of earlier attempts, initiated by Elliott and co-workers, to extend the interacting boson model of Arima and Iachello by the inclusion of neutron-proton s and d bosons with T = 1 (IBM-3) as well as T = 0 (IBM-4). It is argued that for the N{approx}Z nuclei that are currently studied experimentally, a different approach is needed which invokes aligned neutron-proton pairs with angular momentum J = 2j and isospin T = 0. This claim is supported by an analysis of shell-model wave functions in terms of pair states. Results of this alternative version of the interacting boson model are compared with shell-model calculations in the 1g{sub 9/2} shell.

Van Isacker, P. [Grand Accelerateur National d'Ions Lourds, CEA/DSM-CNRS/IN2P3 BP 55027, F-14076 Caen Cedex 5 (France)

2011-05-06T23:59:59.000Z

294

Delta resonance and nonlocal effects in pion photoproduction from nuclei  

SciTech Connect

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

295

Stability of bubble nuclei through Shell-Effects  

E-Print Network (OSTI)

We investigate the shell structure of bubble nuclei in simple phenomenological shell models and study their binding energy as a function of the radii and of the number of neutron and protons using Strutinsky's method. Shell effects come about, on the one hand, by the high degeneracy of levels with large angular momentum and, on the other, by the big energy gaps between states with a different number of radial nodes. Shell energies down to -40 MeV are shown to occur for certain magic nuclei. Estimates demonstrate that the calculated shell effects for certain magic numbers of constituents are probably large enough to produce stability against fission, alpha-, and beta-decay. No bubble solutions are found for mass number A < 450.

Klaus Dietrich; Krzysztof Pomorski

1997-04-25T23:59:59.000Z

296

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

297

Review of Particle Physics  

Science Journals Connector (OSTI)

This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 1900 new measurements from 700 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review.

R. M. Barnett et al.

1996-07-01T23:59:59.000Z

298

Particles and Sources  

Science Journals Connector (OSTI)

It is proposed that the phenomenological theory of particles be based on the source concept, which is abstracted from the physical possibility of creating or annihilating any particle in a suitable collision. The source representation displays both the momentum and the space-time characteristics of particle behavior. Topics discussed include: spin and statistics, charge and the Euclidean postulate, massless particles, and SU3 and spin. It is emphasized that the source description is logically independent of hypotheses concerning the fundamental nature of particles.

Julian Schwinger

1966-12-23T23:59:59.000Z

299

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

SciTech Connect

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

300

Incoherent photoproduction of pseudoscalar mesons off nuclei at forward angles  

SciTech Connect

Recent advances in the photon tagging facilities together with the novel, high-resolution fast calorimetry make it possible to perform photoproduction cross section measurements of pseudoscalar mesons on nuclei with a percent level accuracy. The extraction of the radiative decay widths, needed for testing the symmetry breaking effects in QCD, from these measurements at small angles is done by the Primakoff method. This method requires theoretical treatment of all processes participating in these reactions at the same percent level. The most updated description of general processes, including the nuclear coherent amplitude, is done in our previous paper. In this work, in the framework of the Glauber multiple scattering theory, we obtain analytical expressions for the incoherent cross section of the photoproduction of pseudoscalar mesons off nuclei accounting for the mesons absorption in nuclei and the Pauli suppression at forward production angles. As illustrations of the obtained formulas, we calculate the incoherent cross section for photoproduction from a closed shell nucleus, {sup 16}O, and from an unclosed shell nucleus, {sup 12}C. These calculations allow one to compare different approaches and estimate their impact on the incoherent cross section of the processes under consideration.

Gevorgyan, Sergey [JINR; Gasparian, Ashot H. [North Carolina Ag. and Tech. St. U; Gan, Liping [University of North Carolina at Wilmington; Larin, Ilya F. [ITEP, Moscow; Khandaker, Mahbubul A. [Idaho State U

2012-01-01T23:59:59.000Z

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301

Muon capture on nuclei: random phase approximation evaluation versus data for 6 $\\le$ Z $\\le$ 94 nuclei  

E-Print Network (OSTI)

We use the random phase approximation to systematically describe the total muon capture rates on all nuclei where they have been measured. We reproduce the experimental values on these nuclei to better than 15% accuracy using the free nucleon weak form factors and residual interactions with a mild $A$ dependency. The isospin dependence and the effects associated with shell closures are fairly well reproduced as well. However, the calculated rates for the same residual interactions would be significantly lower than the data if the in-medium quenching of the axial-vector coupling constant is employed to other than the true Gamow-Teller amplitudes. Our calculation thus suggests that no quenching is needed in the description of semileptonic weak processes involving higher multipole transitions and momentum transfer $\\sim m_{\\mu}$, with obvious importance to analogous weak processes.

Nikolaj Thomas Zinner; Karlheinz Langanke; Petr Vogel

2006-06-01T23:59:59.000Z

302

Neutrino and Cosmic-Ray Emission and Cumulative Background from Radiatively Inefficient Accretion Flows in Low-Luminosity Active Galactic Nuclei  

E-Print Network (OSTI)

We study high-energy neutrino and cosmic-ray (CR) emission from the cores of low-luminosity active galactic nuclei (LLAGN). In LLAGN, the thermalization of particles is expected to be incomplete in radiatively inefficient accretion flows (RIAFs), allowing the existence of non-thermal particles. In this work, assuming stochastic particle acceleration due to turbulence in RIAFs, we solve the Fokker-Planck equation and calculate spectra of escaping neutrinos and CRs. The RIAF in LLAGN can emit CR protons with $\\gtrsim10$ PeV energies and TeV-PeV neutrinos generated via $pp$ and/or $p\\gamma$ reactions. We find that, if $\\sim1$% of the accretion luminosity is carried away by non-thermal ions, the diffuse neutrino intensity from the cores of LLAGN may be as high as $E_\

Shigeo S. Kimura; Kohta Murase; Kenji Toma

2014-11-13T23:59:59.000Z

303

Estimation of Performance of an Active Well Coincidence Counter Equipped with Boron-Coated Straw Neutron Detectors - 13401  

SciTech Connect

He-3, a very rare isotope of natural helium gas, has ideal properties for the detection of thermal neutrons. As such it has become the standard material for neutron detectors and sees ubiquitous use within many radiometric applications that require neutron sensitivity. Until recently, there has been a fairly abundant supply of He-3. However, with the reduction in nuclear weapons, production of tritium ceased decades ago and the stockpile has largely decayed away, reducing the available He-3 supply to a small fraction of that needed for neutron detection. A suitable and rapidly-deployable replacement technology for neutron detectors must be found. Many potential replacement technologies are under active investigation and development. One broad class of technologies utilizes B-10 as a neutron capture medium in coatings on the internal surfaces of proportional detectors. A particular implementation of this sort of technology is the boron-coated 'straw' (BCS) detectors under development by Proportional Technologies, Inc. (PTi). This technology employs a coating of B-10 enriched boron carbide (B{sub 4}C) on the inside of narrow tubes, roughly 4 mm in diameter. A neutron counter (e.g. a slab, a well counter, or a large assay counter designed to accommodate 200 liter drums) could be constructed by distributing these narrow tubes throughout the polyethylene body of the counter. One type of neutron counter that is of particular importance to safeguards applications is the Active Well Coincidence Counter (AWCC), which is a Los Alamos design that traditionally employs 42 He-3 detectors. This is a very flexible design which can accurately assay small samples of uranium- and plutonium-bearing materials. Utilizing the MCNPX code and benchmarking against measurements where possible, the standard AWCC has been redesigned to utilize the BCS technology. Particular aspects of the counter performance include the single-neutron ('singles') detection efficiency and the time constant for the decrease in neutron population in the counter following a fission event (a.k.a. the die-away time). Results of the modeling and optimization are presented. (authors)

Young, B.M. [Canberra Industries, Inc., 800 Research Parkway, Meriden, CT 06450 (United States)] [Canberra Industries, Inc., 800 Research Parkway, Meriden, CT 06450 (United States); Lacy, J.L.; Athanasiades, A. [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States)] [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States)

2013-07-01T23:59:59.000Z

304

Synthesis and textural evolution of alumina particles with mesoporous structures  

SciTech Connect

Alumina particles with mesostructures were synthesized through a chemical precipitation method by using different inorganic aluminum salts followed by a heterogeneous azeotropic distillation and calcination process. The obtained mesoporous {gamma}-alumina particles were systematically characterized by the X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption measurement. Effects of the aluminum salt counter anion, pH value and the azeotropic distillation process on the structural or textural evolution of alumina particles were investigated. It is found that Cl{sup -} in the reaction solution can restrain the textural evolution of the resultant precipitates into two-dimensional crystallized pseudoboehmite lamellae during the heterogeneous azeotropic distillation, and then transformed into {gamma}-Al{sub 2}O{sub 3} particles with mesostructures after further calcination at 1173 K, whereas coexisting SO{sub 4}{sup 2-} can promote above morphology evolution and then transformed into {gamma}-Al{sub 2}O{sub 3} nanofibers after calcination at 1173 K. Moreover nearly all materials retain relatively high specific surface areas larger than 100 m{sup 2} g{sup -1} even after calcinations at 1173 K. - Graphical abstract: Co-existing Cl{sup -} is beneficial for the formation of {gamma}-alumina nanoparticles with mesostructures during the precipitation process. Interparticle and intraparticle mesopores can be derived from acidic solution and near neutral solution, respectively.

Liu Xun [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Peng Tianyou, E-mail: typeng@whu.edu.c [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Yao Jinchun; Lv Hongjin; Huang Cheng [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China)

2010-06-15T23:59:59.000Z

305

Rotational character change of the one-phonon and two-phonon $\\gamma$ vibration in odd-$A$ nuclei  

E-Print Network (OSTI)

\\item[Background] The $\\gamma$ vibration is the most typical low-lying collective motion prevailing the nuclear chart. But only few one-phonon rotational bands in odd-$A$ nuclei have been known. Furthermore, two-phonon states, even the band head, have been observed in a very limited number of nuclides not only of odd-$A$ but even-even. \\item[Purpose] Among them, that in $^{105}$Mo is unique in that Coriolis effects are expected to be stronger than in $^{103}$Nb and $^{105}$Nb on which theoretical studies were reported. Then the purpose of the present work is to study $^{105}$Mo paying attention to rotational character change of the one-phonon and two-phonon bands in comparison with the present author's previous studies on $^{103}$Nb and $^{105}$Nb. \\item[Method] The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. \\item[Results] The present model reproduces the observed yrast zero-phonon and...

Matsuzaki, Masayuki

2014-01-01T23:59:59.000Z

306

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

307

ACCELERATION OF CHARGED PARTICLES  

Science Journals Connector (OSTI)

... similarity in its behaviour to that of a synchronous motor, he has called a 'synchroton'. It is shown that a particle, the energy of which (called its ' ...

1946-03-23T23:59:59.000Z

308

Carl Gagliardi Modern Particle  

NLE Websites -- All DOE Office Websites (Extended Search)

Carl Gagliardi Modern Particle Accelerators and Detectors A Household Survey Carl A. Gagliardi 2 Carl Gagliardi Alyson Clarke * High school All Star swimmer * My niece To do well...

309

Deformed Wong particles  

Science Journals Connector (OSTI)

By generalizing the Feynman proof of the Lorentz force law, recently reported by Dyson, we derive equations of motion for particles possessing internal degrees of freedom Ia which do not, in general, generate a finite algebra. We obtain consistency criteria for fields which interact with such particles. We use the results to argue that SU(2) gauge invariance is broken to U(1) when a particle with internal SUq(2) degrees of freedom is coupled to SU(2) gauge fields. We further claim that when such an SUq(2) particle acts as a source for the field theory, the second-rank antisymmetric field tensor, in general, cannot be globally defined.

A. Stern and I. Yakushin

1993-11-15T23:59:59.000Z

310

Characterization of novel Hamamatsu Multi Pixel Photon Counter (MPPC) arrays for the GlueX experiment  

SciTech Connect

The novel Hamamatsu Multi Pixel Photon Counter Array S12045(X) is an array of 16 individual MPPCs (3x3 mm{sup 2}) (further in the paper MPPC array channel) each with 3600 G-APD (Geiger-mode Avalanche Photodiodes) pixels (50x50 [{micro}m{sup 2}]). Each MPPC in the array works with its individual reverse bias voltage mode (around 70 V). The paper summarizes the characterization process of MPPC arrays used in GlueX experiment (Hall D, Jefferson Lab). We studied the main features of each MPPC array channel for 2800 MPPC arrays at different temperatures. Two measurement stations were built to extract gain, breakdown voltage, photo detection efficiency (PDE), optical crosstalk and dark rate for each MPPC array channel. The hardware and the data analysis are described, which includes new analytical expressions to obtain the mean number of photo-electrons and optical crosstalk. The dynamical behavior of characterization parameters is presented as well.

Soto, Orlando [Universidad T?cnica Federico Santa Mar?a; Rojas, Rimsky [Universidad T?cnica Federico Santa Mar?a; Kuleshov, Sergey V. [Universidad T?cnica Federico Santa Mar?a; Hakobyan, Hayk [Universidad T?cnica Federico Santa Mar?a; Toro, Alam [Universidad T?cnica Federico Santa Mar?a; Brooks, William K. [Universidad T?cnica Federico Santa Mar?a

2013-12-01T23:59:59.000Z

311

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...

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

2011-01-01T23:59:59.000Z

312

Quasi-particle and collective magnetism: Rotation, pairing and blocking in high-K isomers  

SciTech Connect

For the first time, a wide range of collective magnetic g-factors gR, obtained from a novel analysis of experimental data for multi-quasi-particle configurations in high-K isomers, is shown to exhibit a striking systematic variation with the relative number of proton and neutron quasi-particles, Np Nn. Using the principle of additivity, the quasi-particle contribution to magnetism in high-K isomers of Lu Re, Z=71 75, has been estimated. Based on these estimates, band-structure branching ratio data are used to explore the behavior of the collective contribution as the number and proton/neutron nature (Np, Nn), of the quasi-particle excitations, change. Basic ideas of pairing, its quenching by quasi-particle excitation and the consequent changes to moment of inertia and collective magnetism are discussed. Existing model calculations do not reproduce the observed gR variation adequately. The paired superfluid system of nucleons in these nuclei, and their excitations, present properties of general physics interest. The new-found systematic behavior of gR in multi-quasi-particle excitations of this unique system, showing variation from close to zero for multi-neutron states to above 0.5 for multi-proton states, opens a fresh window on these effects and raises the important question of just which nucleons contribute to the collective properties of these nuclei.

Stone, N. J. [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); Stone, Jirina R [ORNL] [ORNL; Walker, P. M. [University of Surrey, UK] [University of Surrey, UK; Bingham, C. R. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)

2013-01-01T23:59:59.000Z

313

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

SciTech Connect

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

314

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

SciTech Connect

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

315

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

316

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. Viñas

2012-07-06T23:59:59.000Z

317

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 constraint limits the amount of power that can be extracted from a given wind farm footprint. The resulting-axis wind turbines (VAWTs) in order to achieve higher power output per unit land area than existing wind

Dabiri, John O.

318

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

319

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

320

In Situ Synthesized Economical Tungsten Dioxide Imbedded in Mesoporous Carbon for Dye-Sensitized Solar Cells As Counter Electrode Catalyst  

Science Journals Connector (OSTI)

In Situ Synthesized Economical Tungsten Dioxide Imbedded in Mesoporous Carbon for Dye-Sensitized Solar Cells As Counter Electrode Catalyst ... As a novel photovoltaic device to convert solar energy to electricity directly, dye-sensitized solar cells (DSCs) have developed considerably over the last 20 years. ...

Mingxing Wu; Xiao Lin; Liang Wang; Wei Guo; Yudi Wang; Jinqiu Xiao; Anders Hagfeldt; Tingli Ma

2011-09-26T23:59:59.000Z

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.


321

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

322

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

323

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

324

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

325

Conversion of relativistic pair energy into radiation in the jets of active galactic nuclei  

E-Print Network (OSTI)

It is generally accepted that relativistic jet outflows power the nonthermal emission from active galactic nuclei (AGN). The composition of these jets -- leptonic versus hadronic -- is still under debate. We investigate the microphysical details of the conversion process of the kinetic energy in collimated relativistic pair outflows into radiation through interactions with the ambient interstellar medium. Viewed from the coordinate system comoving with the pair outflow, the interstellar protons and electrons represent a proton-electron beam propagating with relativistic speed in the pair plasma. We demonstrate that the beam excites both electrostatic and low-frequency magnetohydrodynamic Alfven-type waves via a two-stream instability in the pair background plasma, and we calculate the time evolution of the distribution functions of the beam particles and the generated plasma wave turbulence power spectra. For standard AGN jet outflow and environment parameters we show that the initial beam distributions of interstellar protons and electrons quickly relax to plateau-distributions in parallel momentum, transferring thereby one-half of the initial energy density of the beam particles to electric field fluctuations of the generated electrostatic turbulence. On considerably longer time scales, the plateaued interstellar electrons and protons will isotropise by their self-generated transverse turbulence and thus be picked-up in the outflow pair plasma. These longer time scales are also characteristic for the development of transverse hydromagnetic turbulence from the plateaued electrons and protons. This hydromagnetic turbulence upstream and downstream is crucial for diffusive shock acceleration to operate at external or internal shocks associated with pair outflows.

R. Schlickeiser; R. Vainio; M. Boettcher; I. Lerche; M. Pohl; C. Schuster

2002-07-02T23:59:59.000Z

326

Muon multiplicity at high energy proton-nuclei collisions  

E-Print Network (OSTI)

Estimation of multiplicity of muons and pions production at high energy proton-nuclei collisions is given. Both QED and QCD contributions are considered for peripheral kinematics of muon pair and $\\sigma$-meson production, keeping in mind it's final conversion to muons. An attempt to explain the excess of positive charged muons compared to negative one in cosmic muon showers is given. We derive the dependence of cross-section of $n$ pairs as a function of $n$ at large n as $d^n(n!n^2)^{-1}$.

E. A. Kuraev; S. Bakmaev; V. Bytev; E. Kokoulina

2007-06-29T23:59:59.000Z

327

Neutron Radii in Nuclei and the Neutron Equation of State  

Science Journals Connector (OSTI)

The root-mean-square radius for neutrons in nuclei is investigated in the Skyrme Hartree-Fock model. The main source of theoretical variation comes from the exchange part of the density-dependent interaction which can be related to a basic property of the neutron equation of state. A precise measurement of the neutron radius in 208Pb would place an important new constraint on the equation of state for neutron matter. The Friedman-Pandharipande neutron equation of state would lead to a very precise value of 0.16±0.02 fm for the difference between the neutron and the proton root-mean-square radius in 208Pb.

B. Alex Brown

2000-12-18T23:59:59.000Z

328

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

329

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

SciTech Connect

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

330

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

331

Toward a New Theory of Spherical Nuclei. II  

Science Journals Connector (OSTI)

A study is carried out of one of several possible mechanisms contributing to the quadrupole moment of the first excited (2+) state of spherical nuclei. The possibility of a deformed solution is investigated for a set of Hartree-Bogoliubov equations describing the 2+ state in an angular-momentum-conserving approximation. In the pairing-plus-quadrupole-quadrupole model, a sharp transition from spherical to deformed density distribution is shown to occur just beyond the value of the quadrupole coupling strength necessary to yield the 2+ excitation energy.

R. M. Dreizler; A. Klein; Chi-Shiang Wu; G. Do Dang

1967-04-20T23:59:59.000Z

332

Volumetric particle modeling  

E-Print Network (OSTI)

................................................................................................ 46 16 Grid cells overlap each other by the maximum diameter of all the particles ................. 46 17 Perpendicular and parallel projection of impact force ................................................... 52 18 Lack of particle motion... displayed using spheres and cubes.............................................................. 127 63 Raytraced ice cube melting............................................................................................ 128 xi LIST...

Dingle, Brent Michael

2007-09-17T23:59:59.000Z

333

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

NLE Websites -- All DOE Office Websites (Extended Search)

Institute Collection: Physics 88 Fast Ignition: Nuclear Fusion with UltraFast Ignition: Nuclear Fusion with Ultra--intenseintense LASERsLASERs Summary: core Atomic nuclei are...

334

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

NLE Websites -- All DOE Office Websites (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...

335

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

NLE Websites -- All DOE Office Websites (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...

336

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

SciTech Connect

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

337

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

338

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

339

Some Particle Properties  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle Properties Particle Properties An Article Written Originally for Midlevel Teachers Back A particle, increasing its speed because of some force acting on it, gains energy of motion. An electron (negatively charged) gains one electron volt (eV) of energy in accelerating through a vacuum from the negative end to the positive end of a one-volt battery. The one eV of energy is given up to other particles as the electron crashes into the positive end. A proton (positively charged) traveling from positive to negative pole through the vacuum would also gain one eV of energy and give it up in its collision with particles in the negative end. This proton collision is similar to the proton beam collision with a target at Fermilab, but at Fermilab the proton energy is much greater.

340

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

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

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

342

Rotational properties of nuclei around $^{254}$No investigated using a spectroscopic-quality Skyrme energy density functional  

E-Print Network (OSTI)

Nuclei in the $Z\\approx100$ mass region represent the heaviest systems where detailed spectroscopic information is experimentally available. Although microscopic-macroscopic and self-consistent models have achieved great success in describing the data in this mass region, a fully satisfying precise theoretical description is still missing. By using fine-tuned parametrizations of the energy density functionals, the present work aims at an improved description of the single-particle properties and rotational bands in the nobelium region. Such locally optimized parameterizations may have better properties when extrapolating towards the superheavy region. Skyrme-Hartree-Fock-Bogolyubov and Lipkin-Nogami methods were used to calculate the quasiparticle energies and rotational bands of nuclei in the nobelium region. Starting from the most recent Skyrme parametrization, UNEDF1, the spin-orbit coupling constants and pairing strengths have been tuned, so as to achieve a better agreement with the excitation spectra and odd-even mass differences in $^{251}$Cf and $^{249}$Bk. The quasiparticle properties of $^{251}$Cf and $^{249}$Bk were very well reproduced. At the same time, crucial deformed neutron and proton shell gaps open up at $N=152$ and $Z=100$, respectively. Rotational bands in Fm, No, and Rf isotopes, where experimental data are available, were also fairly well described. To help future improvements towards a more precise description, small deficiencies of the approach were carefully identified. In the $Z\\approx100$ mass region, larger spin-orbit strengths than those from global adjustments lead to improved agreement with data. Puzzling effects of particle-number restoration on the calculated moment of inertia, at odds with the experimental behaviour, require further scrutiny.

Yue Shi; J. Dobaczewski; P. T. Greenlees

2013-12-16T23:59:59.000Z

343

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

344

Simultaneous multiparticle emissions in hot nuclei evaporation process  

SciTech Connect

This work presents a new mechanism for the evaporation with simultaneous particles emission mechanism in the evaporation chain as new channels opened to high excitation energy regime of the compound nucleus. The probability of multiple simultaneous emissions is determined based on phase space approach. A Monte Carlo simulation is employed to compute the final average yield of emitted particles after the decay chain. The neutron, proton, alpha and fission yields are obtained and compared to the conventional calculation with sequential simple particles emission and the relevance of the different channels in competition is also analyzed.

Santos, B. M. [Instituto de Fisica - Universidade Federal Fluminense Av. Gal. Milton Tavares de Souza, 24210-346 Niteroi. RJ (Brazil); De Assis, L. P.; Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas - CBPF Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro. RJ (Brazil)

2013-03-25T23:59:59.000Z

345

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

346

The Particle Adventure  

NLE Websites -- All DOE Office Websites (Extended Search)

Shortcomings Shortcomings of the first data Shortcomings of the first data The data were convincing but not perfect, and there were significant shortcomings. For one thing, by July 4, 2012, there weren't enough statistics to measure whether the rate at which this particle (the Higgs boson) decays to various collections of less massive particles (the "branching ratios") are those predicted by the Standard Model. A "branching ratio" is simply the probability that a particle will decay via a given decay channel. These ratios are predicted by the Standard Model, and measured by observing the same particle decay over and over again. The next plot shows the best measurements we can make of the branching ratios with the data available in 2013. Since these are the ratios to the

347

Fermilab | Science | Particle Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

study topics such as dark matter and dark energy. Learn more about dark matter and dark energy. Muons thumbnail Particles called muons could help scientists see hidden or rare...

348

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

349

Review of Particle Physics  

Science Journals Connector (OSTI)

This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 1600 new measurements from 550 papers, we list, evaluate, and average measured properties of gauge bosons, leptons...

1998-01-01T23:59:59.000Z

350

Magnetic Particle Process Improvement  

SciTech Connect

The magnetic particle testing process is performed to find linear, surface and near surface discontinuities in ferromagnetic test materials. A wet fluorescent method is used at Honeywell Federal Manufacturing & Technologies (FM&T). This method employs a liquid carrier mixed with iron oxide particles in suspension, and the particles used in the method are coated with a fluorescent dye to make them visible under a black light. The process in its current state employs the use of a tank of liquid solution of a mineral oil carrier with iron oxide particles in suspension. The change to the use of an aerosol delivery system with the same material reduces the amount of waste involved in the process while preserving the sensitivity of the testing, shortens the flowtime for the test, and saves labor and material costs.

Hubert, R.R.

2002-08-13T23:59:59.000Z

351

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

352

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.

353

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

354

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 für 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.

355

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

356

SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS  

E-Print Network (OSTI)

L-263 SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS vu par les noyaux. Abstract. - The spin-dependent scattering length of slow neutrons by the nuclei 23 can be of practical importance in many thermal neutron scattering experiments. A new method, called

Boyer, Edmond

357

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

358

Decay of accelerated particles  

Science Journals Connector (OSTI)

We study how the decay properties of particles are changed by acceleration. It is shown that under the influence of acceleration (1) the lifetime of particles is modified and (2) new processes (such as the decay of the proton) become possible. This is illustrated by considering scalar models for the decay of muons, pions, and protons. We discuss the close conceptual relation between these processes and the Unruh effect.

Rainer Müller

1997-07-15T23:59:59.000Z

359

ELEMENTARY PARTICLE INTERACTIONS  

SciTech Connect

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

360

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

SciTech Connect

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

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

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

362

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

SciTech Connect

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

363

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

SciTech Connect

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

364

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

SciTech Connect

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

365

Role of dopant counter-anion functionality in polyaniline salts/blends and implications to morphology  

SciTech Connect

Polyanilines are of particular current interest primarily due to their relative ease of synthesis, low cost and stable conductivity in air. The insulating, polyaniline emeraldine base (PANI-EB) form becomes electrically conducting by preferential protonation or doping the imine nitrogen sites to yield an electrically conducting polyaniline emeraldine salt (PANI-ES). In this paper, wide and small angle X-ray scattering techniques (i.e., WAXS and SAXS) and light microscopy are used to characterize the influence of the dopant`s structure on the morphology of both polyaniline salt and blend. In an attempt to modify the morphology of the PANI-ES, the authors have evaluated a number of doping acids (i.e., methane sulfonic acid (HMSA), butane sulfonic acid (HBSA), dodecyl benzene sulfonic acid (HDBSA) and camphor sulfonic acid (HCSA)) that vary in size and polarity to better understanding the role of the acid in PANI-ES`s morphology and the resulting electrical conductivity. The other goal was to investigate the effect of the counter-anion structure on the nature of the phase separated PANI-ES network. The shape of the PANI-ES network in the host polycaprolactam has important implications on the nature of conduction behavior and the final electrical conductivity of the blend.

Hopkins, A.R.; Rasmussen, P.G. [Univ. of Michigan, Ann Arbor, MI (United States); Basheer, R.A. [General Motors Research and Development Center, Warren, MI (United States). Polymers Dept.; Annis, B.K.; Wignall, G.D. [Oak Ridge National Lab., TN (United States)

1997-04-01T23:59:59.000Z

366

Role of dopant counter-anion functionality in polyaniline salts/blends and implications to morphology  

SciTech Connect

In this paper, wide and small angle X-ray scattering techniques (i.e., WAXS and SAXS) and light microscopy are used to characterize the influence of the dopant`s structure on the morphology of both polyaniline salt and blend. In an attempt to modify the morphology of the PANI-ES, the authors have evaluated a number of doping acids (i.e., methane sulfonic acid (HMSA), butane sulfonic acid (HBSA), dodecyl benzene sulfonic acid (HDBSA) and camphor sulfonic acid (HCSA)) that vary in size and polarity to better understand the role of the acid in PANI-ES`s morphology and the resulting electrical conductivity. These salts were solution blended with polycaprolactam using hexafluoro-2-propanol (HFIP) as a solvent. The other goal was to investigate the effect of the counter-anion structure on the nature of the phase separated PANI-ES network. The shape of the PANI-ES network in the host polycaprolactam has important implications on the nature of conduction behavior and the final electrical conductivity of the blend.

Hopkins, A.R.; Rasmussen, P.G. [Univ. of Michigan, Ann Arbor, MI (United States); Basheer, R.A. [General Motors Research and Development Center, Warren, MI (United States). Polymers Dept.; Annis, B.K.; Wignall, G.D. [Oak Ridge National Lab., TN (United States)

1997-03-01T23:59:59.000Z

367

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

368

Single Particle Laser Ablation | EMSL  

NLE Websites -- All DOE Office Websites (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...

369

A NEW COSMOLOGICAL DISTANCE MEASURE USING ACTIVE GALACTIC NUCLEI  

SciTech Connect

Accurate distances to celestial objects are key to establishing the age and energy density of the universe and the nature of dark energy. A distance measure using active galactic nuclei (AGNs) has been sought for more than 40 years, as they are extremely luminous and can be observed at very large distances. We report here the discovery of an accurate luminosity distance measure using AGNs. We use the tight relationship between the luminosity of an AGN and the radius of its broad-line region established via reverberation mapping to determine the luminosity distances to a sample of 38 AGNs. All reliable distance measures up to now have been limited to moderate redshift-AGNs will, for the first time, allow distances to be estimated to z {approx} 4, where variations of dark energy and alternate gravity theories can be probed.

Watson, D.; Denney, K. D.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Oe (Denmark); Davis, T. M. [School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia)

2011-10-20T23:59:59.000Z

370

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

371

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

372

Advanced modeling of reaction cross sections for light nuclei  

SciTech Connect

The shell model/R-matrix technique of calculating nuclear reaction cross sections for light projectiles incident on light nuclei is discussed, particularly in the application of the technique to thermonuclear reactions. Details are presented on the computational methods for the shell model which display how easily the calculations can be performed. Results of the shell model/R-matrix technique are discussed as are some of the problems encountered in picking an appropriate nucleon-nucleon interaction for the large model spaces which must be used for current problems. The status of our work on developing an effective nucleon-nucleon interaction for use in large-basis shell model calculations is presented. This new interaction is based on a combination of global constraints and microscopic nuclear data. 23 refs., 6 figs., 2 tabs.

Resler, D.A.

1991-01-01T23:59:59.000Z

373

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. Castaños; P. O. Hess

1994-07-12T23:59:59.000Z

374

Nuclear shell effect and collinear tripartition of nuclei  

E-Print Network (OSTI)

A possibility of formation of the three reaction products having comparable masses at the spontaneous fission of $^{252}$Cf is theoretically explored. This work is aimed to study the mechanism leading to observation of the reaction products with masses $M_1=$136---140 and $M_2=$68---72 in coincidence by the FOBOS group in JINR. The same type of ternary fission decay has been observed in the reaction $^{235}$U(n$_{\\rm th}$,fff). The potential energy surface for the ternary system forming a collinear nuclear chain is calculated for the wide range of mass and charge numbers of constituent nuclei. The results of the PES for the tripartition of $^{252}$Cf(sf,fff) shows, that we have favorable dynamical conditions for the formation of fragments with mass combinations of clusters $^{68-70}$Ni with $^{130-132}$Sn and with missing cluster $^{48-52}$Ca.

Nasirov, A K; Tashkhodjaev, R B

2014-01-01T23:59:59.000Z

375

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

376

Particle-vibration coupling within covariant density functional theory  

E-Print Network (OSTI)

Covariant density functional theory, which has so far been applied only within the framework of static and time dependent mean field theory is extended to include Particle-Vibration Coupling (PVC) in a consistent way. Starting from a conventional energy functional we calculate the low-lying collective vibrations in Relativistic Random Phase Approximation (RRPA) and construct an energy dependent self-energy for the Dyson equation. The resulting Bethe-Salpeter equation in the particle-hole ($ph$) channel is solved in the Time Blocking Approximation (TBA). No additional parameters are used and double counting is avoided by a proper subtraction method. The same energy functional, i.e. the same set of coupling constants, generates the Dirac-Hartree single-particle spectrum, the static part of the residual $ph$-interaction and the particle-phonon coupling vertices. Therefore a fully consistent description of nuclear excited states is developed. This method is applied for an investigation of damping phenomena in the spherical nuclei with closed shells $^{208}$Pb and $^{132}$Sn. Since the phonon coupling terms enrich the RRPA spectrum with a multitude of $ph\\otimes$phonon components a noticeable fragmentation of the giant resonances is found, which is in full agreement with experimental data and with results of the semi-phenomenological non-relativistic approach.

E. Litvinova; P. Ring; V. Tselyaev

2007-05-08T23:59:59.000Z

377

Vapor-deposited /sup 235/UO/sub 2/ layers for an ultra-high-sensitivity fission counter  

SciTech Connect

After evaluating the properties of uranium oxide coatings prepared by electrodeposition, painting and physical vapor deposition, the vapor deposition method was selected as being preferable for preparing coatings on aluminum electrodes having a total area of 5 m/sup 2/. The electrodes were used in an experimental fission chamber designed at the Oak Ridge National Laboratory for use as a neutron flux monitor the Clinch River Breeder Reactor. Initial testing of the Ultra-High Sensitivity Fission Counter (UHSFC) indicated that a tenfold increase in sensitivity was achieved as compared to commercially available fission counters. Techniques used in vapor coating and characterizing the /sup 235/UO/sub 2/ deposits on the large-area curved substrates are described.

Adair, H.L.; Byrum, B.L.; Dailey, J.M.; Gibson, J.R.

1982-01-01T23:59:59.000Z

378

A review of "Nuns’ Chronicles and Convent Culture in Renaissance and Counter-Reformation Italy." by K. J. P. Lowe  

E-Print Network (OSTI)

150 SEVENTEENTH-CENTURY NEWS Women?s writing scholars and English drama historians will benefit from her study. K. J. P. Lowe. Nuns? Chronicles and Convent Culture in Renaissance and Counter- Reformation Italy. Cambridge: Cambridge University... Press, 2003. xvi + 437 pp. + 42 illus. $90.00. Review by THOMAS WORCESTER, COLLEGE OF THE HOLY CROSS. Vernacular chronicles of three convents form the basis of this study: Santa Maria delle Vergini (Venice), known as Le Vergini; Santa Maria...

Thomas Worcester

2005-01-01T23:59:59.000Z

379

Modified Sagnac experiment for measuring travel-time difference between counter-propagating light beams in a uniformly moving fiber  

E-Print Network (OSTI)

A fiber optic conveyor has been developed for investigating the travel-time difference between two counter-propagating light beams in uniformly moving fiber. Our finding is that there is a travel-time difference Deltat=2vDeltal/c^2 in a fiber segment of length Deltal moving with the source and detector at a speed v, whether the segment is moving uniformly or circularly.

Ruyong Wang; Yi Zheng; Aiping Yao; Dean Langley

2006-09-25T23:59:59.000Z

380

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

SciTech Connect

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

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

Fine Particles in Soils  

NLE Websites -- All DOE Office Websites (Extended Search)

Fine Particles in Soils Fine Particles in Soils Nature Bulletin No. 582 November 28, 1959 Forest Preserve District of Cook County Daniel Ryan, President Roberts Mann, Conservation Editor David H. Thompson, Senior Naturalist FINE PARTICLES IN SOILS If a farmer, while plowing, is visited in the field by another farmer, invariably the visitor will pick up a handful of turned over earth and knead it with his fingers while they talk. The "feel" of it tells him a lot about the texture and structure of that soil. He knows that both are important factors in the growth of plants and determine the crops that may be obtained from the land. Soil is a combination of three different things About half of it is solid matter; the other half consists of air and water The solid portion is composed of organic and inorganic materials.

382

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

383

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

384

Poverty, Islamist Extremism, and the Debacle of Doha Round Counter-Terrorism: Part Two of a Trilogy – Non-Agricultural Market Access and Services Trade  

E-Print Network (OSTI)

The title of the Trilogy on the Doha Round, of which this article is Part Two, connotes the general argument: the Round is a failed instrument of counter-terrorism. The Round, launched in November 2001, was supposed to ...

Bhala, Raj

2012-02-23T23:59:59.000Z

385

Background and muon counting rates in underground muon measurements with a plastic scintillator counter based on a wavelength shifting fibre and a multi-pixel avalanche photodiode readout  

Science Journals Connector (OSTI)

In this short note we present results of background measurements carried out with polystyrene based cast plastic 12.0×12.0×3.0 cm3 size scintillator counter with a wavelength shifting fibre and a multi-pixel Geig...

Vladimir I. Volchenko; Evgeniy V. Akhrameev…

2010-06-01T23:59:59.000Z

386

Production of heavy and superheavy neutron-rich nuclei in neutron capture processes  

Science Journals Connector (OSTI)

The neutron capture process is considered as an alternative method for production of superheavy (SH) nuclei. Strong neutron fluxes might be provided by nuclear reactors and nuclear explosions in the laboratory frame and by supernova explosions in nature. All these cases are discussed in the paper. There are two gaps of short-lived nuclei (one is the well-known fermium gap and the other one is located in the region of Z=106–108 and N?170) which impede the formation of SH nuclei by rather weak neutron fluxes realized at available nuclear reactors. We find that in the course of multiple (rather “soft”) nuclear explosions these gaps may be easily bypassed, and thus, a measurable amount of the neutron-rich long-living SH nuclei located at the island of stability may be synthesized. Existing pulsed reactors do not allow one to bypass these gaps. We formulate requirements for the pulsed reactors of the next generation that could be used for production of long-living SH nuclei. Natural formation of SH nuclei (in supernova explosions) is also discussed. The yield of SH nuclei relative to lead is estimated to be about 10?12, which is not beyond the experimental sensitivity for a search of SH elements in cosmic rays.

V. I. Zagrebaev; A. V. Karpov; I. N. Mishustin; Walter Greiner

2011-10-24T23:59:59.000Z

387

Future of superheavy element research: Which nuclei could be synthesized within the next few years?  

E-Print Network (OSTI)

Low values of the fusion cross sections and very short half-lives of nuclei with Z$>$120 put obstacles in synthesis of new elements. Different nuclear reactions (fusion of stable and radioactive nuclei, multi-nucleon transfers and neutron capture), which could be used for the production of new isotopes of superheavy (SH) elements, are discussed in the paper. The gap of unknown SH nuclei, located between the isotopes which were produced earlier in the cold and hot fusion reactions, can be filled in fusion reactions of $^{48}$Ca with available lighter isotopes of Pu, Am, and Cm. Cross sections for the production of these nuclei are predicted to be rather large, and the corresponding experiments can be easily performed at existing facilities. For the first time, a narrow pathway is found to the middle of the island of stability owing to possible $\\beta^+$-decay of SH isotopes which can be formed in ordinary fusion reactions of stable nuclei. Multi-nucleon transfer processes at near barrier collisions of heavy (and very heavy, U-like) ions are shown to be quite realistic reaction mechanism allowing us to produce new neutron enriched heavy nuclei located in the unexplored upper part of the nuclear map. Neutron capture reactions can be also used for the production of the long-living neutron rich SH nuclei. Strong neutron fluxes might be provided by pulsed nuclear reactors and by nuclear explosions in laboratory conditions and by supernova explosions in nature. All these possibilities are discussed in the paper.

Valeriy Zagrebaev; Alexander Karpov; Walter Greiner

2012-07-24T23:59:59.000Z

388

Multiwire-Proportional-Counter Measurement of the ML Orbital-Electron-Capture Ratio in Ge71 Decay  

Science Journals Connector (OSTI)

The ML orbital-electron-capture ratio in Ge71 decay has been measured in a wall-less multiwire proportional counter containing the gaseous radioactive compound Ge71H4. The counter was filled to 6 atm with argon containing 15 cm Hg propane. Recent advances in proportional-counter spectrometry below 500 eV have extended the sensitivity for precision measurement to the detection of single- and few-electron events down to essentially zero energy, even in the presence of high intensities of more energetic radiation. These improvements are the result not only of the sophistication of the low-noise electronic system, but also of the present investigation of the degradation spectrum (low-energy tails and afterpulses) from spectral peaks, and of the resolution from each other of single- and few-electron spectra by using computer analysis. A fully transistorized electronic system was developed which includes a special dc-coupled logic unit with zero-time recovery (updating) to perform the following operations: (i) to ensure proper anticoincidence functioning of the ring counter; (ii) to provide paralysis pulses necessary to block possible afterpulses following an ionizing event in either the ring or central counter; and (iii) to eliminate the phenomenon of front- and backedge clipping of large pulses into small ones by the action of the anticoincidence gate. Measurements were made of the K, L, and M peaks, having mean energies of 10.37 keV, 1298, and 158 eV, respectively, and the resulting orbital-electron-capture ratios were determined to be PLPK=0.117±0.001 and PMPL=0.162±0.003. These ratios are compared with theoretical results. Whereas the present LK capture ratio is in closer agreement with theory corrected for exchange according to Bahcall, the theoretical prediction of the ML ratio by Bahcall with correction for exchange lies approximately 7% above the present value, which agrees well with a recent theoretical calculation by Vatai. The half-life of Ge71 was found by least-squares fitting to be 11.15 ± 0.15 days, by following the decay of K x rays from a solid source with a Ge(Li) x-ray detector.

H. Genz; J. P. Renier; J. G. Pengra; R. W. Fink

1971-01-01T23:59:59.000Z

389

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

390

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

391

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

392

Rotational character change of the one-phonon and two-phonon $?$ vibration in odd-$A$ nuclei  

E-Print Network (OSTI)

\\item[Background] The $\\gamma$ vibration is the most typical low-lying collective motion prevailing the nuclear chart. But only few one-phonon rotational bands in odd-$A$ nuclei have been known. Furthermore, two-phonon states, even the band head, have been observed in a very limited number of nuclides not only of odd-$A$ but even-even. \\item[Purpose] Among them, that in $^{105}$Mo is unique in that Coriolis effects are expected to be stronger than in $^{103}$Nb and $^{105}$Nb on which theoretical studies were reported. Then the purpose of the present work is to study $^{105}$Mo paying attention to rotational character change of the one-phonon and two-phonon bands in comparison with the present author's previous studies on $^{103}$Nb and $^{105}$Nb. \\item[Method] The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. \\item[Results] The present model reproduces the observed yrast zero-phonon and one-phonon bands well. The emerging general feature of the rotational character change from low spin to high spin is elucidated. In particular, the reason why the one-phonon band does not exhibit signature splitting is clarified. The calculated collectivity of the two-phonon states, however, is located higher than observed. \\item[Conclusions] The observed spectra of the yrast zero-phonon and one-phonon bands have been reproduced well. But properties of the two-phonon states, in particular the anharmonicity of the spectra, have not been accounted for.

Masayuki Matsuzaki

2014-10-21T23:59:59.000Z

393

Light Nuclei and Isotope Abundances in Cosmic Rays. Results from AMS-01  

E-Print Network (OSTI)

Observations of the chemical and isotopic composition of light cosmic-ray nuclei can be used to constrain the astrophysical models of cosmic-ray transport and interactions in the Galaxy. Nearly 200,000 light nuclei (Z>2) have been observed by AMS-01 during the 10-day flight STS-91 in June 1998. Using these data, we have measured the relative abundance of light nuclei Li, Be, B and C in the kinetic energy range 0.35 - 45 GeV/nucleon.

N. Tomassetti

2011-06-11T23:59:59.000Z

394

Energy-weighted sum rules connecting ?Z?=?2 nuclei within the SO(8) model  

SciTech Connect

Energy-weighted sum rules associated with ?Z?=?2 nuclei are obtained for the Fermi and the Gamow-Teller operators within the SO(8) model. It is found that there is a dominance of contribution of a single state of the intermediate nucleus to the sum rule. The results confirm founding obtained within the SO(5) model that the energy-weighted sum rules of ?Z?=?2 nuclei are governed by the residual interactions of nuclear Hamiltonian. A short discussion concerning some aspects of energy weighted sum rules in the case of realistic nuclei is included.

Štefánik, Dušan [Comenius University, Mlynská dolina F1, SK-842 48 Bratislava (Slovenia); Šimkovic, Fedor [IEAP CTU, CZ-128 00 Prague, Czech Republic and BLTP, JINR, 141980 Dubna, Moscow region (Russian Federation); Faessler, Amand [Inst. of Theor. Phys., University of Tuebingen, D-72076 Tuebingen (Germany)

2013-12-30T23:59:59.000Z

395

The Particle Adventure | How do we experiment with tiny particles? |  

NLE Websites -- All DOE Office Websites (Extended Search)

Accelerating particles Accelerating particles Accelerating particles It is fairly easy to obtain particles. Physicists get electrons by heating metals; they get protons by robbing hydrogen of its electron; etc. Accelerators speed up charged particles by creating large electric fields which attract or repel the particles. This field is then moved down the accelerator, "pushing" the particles along. In a linear accelerator the field is due to traveling electromagnetic (E-M) waves. When an E-M wave hits a bunch of particles, those in the back get the biggest boost, while those in the front get less of a boost. In this fashion, the particles "ride" the front of the E-M wave like a bunch of surfers. The next page shows this process in an easier to understand animation

396

Particle Size Characterization  

E-Print Network (OSTI)

NISTrecommended p r a c t i c e g u i d e Special Publication 960-1 #12;i Particle Size Characterization Ajit.S. Department of Commerce Donald L. Evans, Secretary Technology Administration Karen H. Brown, Acting Under Steve Freiman, Said Jahanmir, James Kelly, Patrick Pei and Dennis Minor and of the Ceramics Division

397

ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI  

SciTech Connect

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

398

Properties of nuclei and elementary particles at low and intermediate energies. Progress report, July 1992--August 1993  

SciTech Connect

Work reported relate to: a 12 ton low energy neutrino detector for neutrino oscillation studies at the San Onofre Reactor Station; new limits on the 17 keV neutrino; time reversal and parity tests for hindered nuclear gamma transitions; and theory of nuclear structure and its application.

Boehm, F.

1993-12-31T23:59:59.000Z

399

Nature of Low-Energy Dipole Strength in Nuclei: The Case of a Resonance at Particle Threshold in 208  

E-Print Network (OSTI)

Universita¨t Darmstadt, D-64289 Darmstadt, Germany 2 Institut fu¨r Theoretische Physik, Universita¨t Giessen, D-35392 Giessen, Germany (Received 31 August 2002; published 18 December 2002) A high a representative case, 208Pb. Indeed, the resonance fluorescence (NRF) experiment reported below was triggered

Ponomarev, Vladimir

400

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

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

Chirality in odd-A Rh isotopes within the triaxial particle rotor model  

SciTech Connect

By adopting the fully quantal triaxial particle-rotor model, the candidate chiral doublet bands in odd-A nuclei {sup 103}Rh and {sup 105}Rh with {pi}g{sub 9/2}{sup -1} x {nu}h{sub 11/2}{sup 2} configuration are studied. For the doublet bands in both nuclei, agreement is excellent for the observed energies over the entire spin range and B(M1)/B(E2) at higher spin range. The evolution of the chiral geometry with angular momentum is discussed in detail by using the angular momentum components and their probability distributions. Chirality is found to change from chiral vibration to nearly static chirality at spin I=37/2 and back to another type of chiral vibration at higher spin. The influence of the triaxial deformation {gamma} is also studied.

Qi, B.; Wang, S. Y. [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University at Weihai, Weihai 264209 (China); Zhang, S. Q. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, 100871 Beijing (China); Meng, J. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, 100871 Beijing (China); School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Department of Physics, University of Stellenbosch, Matieland 7602 (South Africa); Koike, T. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

2011-03-15T23:59:59.000Z

402

On Board, In-use Sensitivity Study of an Electrical Aerosol Detector (EAD) and Condensation Particle Counter (CPC) for Second by Second Diesel PM Measurements  

Energy.gov (U.S. Department of Energy (DOE))

Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs.

403

Self-absorbed synchroton sources in active galactic nuclei  

SciTech Connect

The properties of compact, homogeneous self-absorbed synchroton sources in active galactic nuclei are explored, calculating the time evolution of such sources after an impulsive injection of relativistic electrons, and the steady state properties in the case of steady injection. The models include synchroton self-Compton losses in a self consistent way. The behavior of the models is determined mainly by the relative importance of synchroton and inverse Compton energy losses. It is found that pure self-absorbed synchroton self-Compton models always predict a continuum spectral slope which is flatter than observed. The problem can be resolved either by including another cooling mechanism for the relativistic electrons, which operates preferentially at low gamma, such as Coulomb collisions with thermal background electrons, or by assuming that there is an external source of primary photons with a luminosity greater than the energy injection rate in relativistic electrons, e.g., the 'UV bump'. The latter possibility, however, predicts an X-ray luminosity which is higher than observed. 30 references.

De kool, M.; Begelman, M.C.; Sikora, M.

1989-02-01T23:59:59.000Z

404

Calculation of Helium nuclei in quenched lattice QCD  

E-Print Network (OSTI)

We present results for the binding energies for ^4He and ^3He nuclei calculated in quenched lattice QCD at the lattice spacing of a =0.128 fm with a heavy quark mass corresponding to m_pi = 0.8 GeV. Enormous computational cost for the nucleus correlation functions is reduced by avoiding redundancy of equivalent contractions stemming from permutation symmetry of protons or neutrons in the nucleus and various other symmetries. To distinguish a bound state from an attractive scattering state, we investigate the volume dependence of the energy difference between the ground state energy of the nucleus channel and the free multi-nucleon states by changing the spatial extent of the lattice from 3.1 fm to 12.3 fm. A finite energy difference left in the infinite spatial volume limit leads to the conclusion that the measured ground states are bounded. It is also encouraging that the measured binding energies and the experimental ones show the same order of magnitude.

T. Yamazaki

2010-12-02T23:59:59.000Z

405

Neutron-Rich Nuclei in Heaven and Earth  

E-Print Network (OSTI)

An accurately calibrated relativistic parametrization is introduced to compute the ground state properties of finite nuclei, their linear response, and the structure of neutron stars. While similar in spirit to the successful NL3 parameter set, it produces an equation of state that is considerably softer -- both for symmetric nuclear matter and for the symmetry energy. This softening appears to be required for an accurate description of several collective modes having different neutron-to-proton ratios. Among the predictions of this model are a symmetric nuclear-matter incompressibility of K=230 MeV and a neutron skin thickness in 208Pb of Rn-Rp=0.21 fm. Further, the impact of such a softening on the properties of neutron stars is as follows: the model predicts a limiting neutron star mass of Mmax=1.72 Msun, a radius of R=12.66 km for a ``canonical'' M=1.4 Msun neutron star, and no (nucleon) direct Urca cooling in neutrons stars with masses below M=1.3 Msun.

B. G. Todd-Rutel; J. Piekarewicz

2005-04-11T23:59:59.000Z

406

Ionization and maximum energy of nuclei in shock acceleration theory  

E-Print Network (OSTI)

We study the acceleration of heavy nuclei at SNR shocks when the process of ionization is taken into account. Heavy atoms ($Z_N >$ few) in the interstellar medium which start the diffusive shock acceleration (DSA) are never fully ionized at the moment of injection. The ionization occurs during the acceleration process, when atoms already move relativistically. For typical environment around SNRs the photo-ionization due to the background galactic radiation dominates over Coulomb collisions. The main consequence of ionization is the reduction of the maximum energy which ions can achieve with respect to the standard result of the DSA. In fact the photo-ionization has a timescale comparable to the beginning of the Sedov-Taylor phase, hence the maximum energy is no more proportional to the nuclear charge, as predicted by standard DSA, but rather to the effective ions' charge during the acceleration process, which is smaller than the total nuclear charge $Z_N$. This result can have a direct consequence in the pred...

Morlino, Giovanni

2011-01-01T23:59:59.000Z

407

SECULAR DYNAMICAL ANTI-FRICTION IN GALACTIC NUCLEI  

SciTech Connect

We identify a gravitational-dynamical process in near-Keplerian potentials of galactic nuclei that occurs when an intermediate-mass black hole (IMBH) is migrating on an eccentric orbit through the stellar cluster towards the central supermassive black hole. We find that, apart from conventional dynamical friction, the IMBH experiences an often much stronger systematic torque due to the secular (i.e., orbit-averaged) interactions with the cluster's stars. The force which results in this torque is applied, counterintuitively, in the same direction as the IMBH's precession and we refer to its action as 'secular dynamical anti-friction' (SDAF). We argue that SDAF, and not the gravitational ejection of stars, is responsible for the IMBH's eccentricity increase seen in the initial stages of previous N-body simulations. Our numerical experiments, supported by qualitative arguments, demonstrate that (1) when the IMBH's precession direction is artificially reversed, the torque changes sign as well, which decreases the orbital eccentricity; (2) the rate of eccentricity growth is sensitive to the IMBH migration rate, with zero systematic eccentricity growth for an IMBH whose orbit is artificially prevented from inward migration; and (3) SDAF is the strongest when the central star cluster is rapidly rotating. This leads to eccentricity growth/decrease for the clusters rotating in the opposite/same direction relative to the IMBH's orbital motion.

Madigan, Ann-Marie; Levin, Yuri, E-mail: madigan@strw.leidenuniv.nl [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands)

2012-07-20T23:59:59.000Z

408

Cloud Condensation Nuclei Profile Value-Added Product  

SciTech Connect

The cloud condensation nuclei (CCN) concentration at cloud base is the most relevant measure of the aerosol that influences droplet formation in clouds. Since the CCN concentration depends on supersaturation, a more general measure of the CCN concentration is the CCN spectrum (values at multiple supersaturations). The CCN spectrum is now measured at the surface at several fixed ARM sites and by the ARM Mobile Facility (AMF), but is not measured at the cloud base. Rather than rely on expensive aircraft measurements for all studies of aerosol effects on clouds, a way to project CCN measurements at the surface to cloud base is needed. Remote sensing of aerosol extinction provides information about the vertical profile of the aerosol, but cannot be directly related to the CCN concentration because the aerosol extinction is strongly influenced by humidification, particularly near cloud base. Ghan and Collins (2004) and Ghan et al. (2006) propose a method to remove the influence of humidification from the extinction profiles and tie the “dry extinction” retrieval to the surface CCN concentration, thus estimating the CCN profile. This methodology has been implemented as the CCN Profile (CCNPROF) value-added product (VAP).

McFarlane, S; Sivaraman, C; Ghan, S

2012-10-08T23:59:59.000Z

409

Star Formation in the Nuclei of Spiral Galaxies  

E-Print Network (OSTI)

Recent observations with the Hubble Space Telescope (HST) have revealed that a large fraction of late-type (Sc and later) spiral galaxies harbor a bright, compact stellar cluster in their dynamical centers. Statistics of the mass, age, and star formation history of these clusters as a function of their host galaxy's Hubble type can be used to constrain models of secular galaxy evolution. Since late-type spirals by definition do not possess a prominent bulge, their nuclear clusters are more easily separated from the underlying disk population. Their spectroscopic properties can thus be studied from ground-based observations. Here, I will discuss plans for, and first results of, a program to study a sample of known nuclear clusters in late-type spirals. For one galaxy (IC 342), we have used high-resolution near infrared spectroscopy to determine the cluster mass directly via its stellar velocity dispersion. The analysis conclusively shows a very low mass-to-light ratio for the nuclear cluster in IC 342, indicative of a young cluster age (about 50 Myrs). From probability arguments, this result favors the scenario that such bursts are a recurrent phenomenon in late-type spiral nuclei.

T. Boeker

1999-12-22T23:59:59.000Z

410

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

SciTech Connect

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

411

Surface properties of neutron-rich exotic nuclei: A source for studying the nuclear symmetry energy  

E-Print Network (OSTI)

We study the correlation between the thickness of the neutron skin in finite nuclei and the nuclear symmetry energy for isotopic chains of even-even Ni, Sn, and Pb nuclei in the framework of the deformed self-consistent mean-field Skyrme HF+BCS method. The symmetry energy, the neutron pressure and the asymmetric compressibility in finite nuclei are calculated within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The mass dependence of the nuclear symmetry energy and the neutron skin thickness are also studied together with the role of the neutron-proton asymmetry. A correlation between the parameters of the equation of state (symmetry energy and its density slope) and the neutron skin is suggested in the isotopic chains of Ni, Sn, and Pb nuclei.

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

2011-01-01T23:59:59.000Z

412

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

Science Journals Connector (OSTI)

The neutrinoless double beta decay of several nuclei that are of interest...76Ge, 82Se, 100Mo, 130Te, and 136Xe) is investigated on the basis of a general Lorentzinvariant effective Lagrangian describing physics ...

A. Ali; A. V. Borisov; D. V. Zhuridov

2010-12-01T23:59:59.000Z

413

Microscopic description of isoscalar giant resonance excitations in ??Ca and ¹¹?SN nuclei  

E-Print Network (OSTI)

This thesis presents a microscopic description of isoscalar giant resonance excitations in ??Ca and ¹¹? Sn nuclei within the self-consistent Skyrme-Hartree-Fock-Random-Phase-Approximation (HF-RPA) theory. Such characteristic features...

Karki, Bhishma

2000-01-01T23:59:59.000Z

414

1d5/2-2s1/2 splitting in light nuclei  

Science Journals Connector (OSTI)

Energy differences between 1d5/2 and 2s1/2 states in light nuclei are reviewed and systematized. A simple model accounts for the Coulomb shifts.

H. T. Fortune

1995-10-01T23:59:59.000Z

415

Brueckner—Hartree—Fock Methods for Nuclear Matter and Finite Nuclei  

Science Journals Connector (OSTI)

In the present chapter we consider some methods developed during recent years for considering correlations in the relativistic description of the properties of nuclear matter and finite nuclei. First of all, w...

Professor Lev N. Savushkin…

2004-01-01T23:59:59.000Z

416

The splitting of hyperfine lines of57Fe nuclei in RF magnetic field  

Science Journals Connector (OSTI)

It is shown experimentally, that for Moessbauer nuclei affected by the radio-frequency (RF) magnetic field of sufficient intensity at frequencies corresponding to ... occurs. Depending on the frequency of alterna...

F. G. Vagizov

1990-08-01T23:59:59.000Z

417

Studies of exotic nuclei with few-nucleon transfer reactions Final Report  

SciTech Connect

This final report summarizes the activities conducted under DOE Grant DE-FG02-04ER41320, titled "Study of exotic nuclei with few-nucleon transfer reactions," A. H. Wuosmaa Principal Investigator.

Wuosmaa, Alan H. [Western Michigan University

2014-10-30T23:59:59.000Z

418

Spin-rotor Interpretation of Identical Bands and Quantized Alignment in Superdeformed A $\\approx$ 190 Nuclei  

E-Print Network (OSTI)

The ``identical'' bands in superdeformed mercury, thallium, and lead nuclei are interpreted as examples of orbital angular momentum rotors with the weak spin-orbit coupling of pseudo-$SU(3)$ symmetries and supersymmetries.

J. A. Cizewski; R. Bijker

1995-06-02T23:59:59.000Z

419

E-Print Network 3.0 - az nuclei application Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Summary: indicates less apoptotic nuclei in QHREDGS compared to the RGDS modified Az-chitosan. See DOI: 10.1039c0sm... on a photocrosslinked form of chitosan, Az-chitosan,...

420

Nonperturbative renormalization of the neutrinoless double-beta operator in p-shell nuclei  

E-Print Network (OSTI)

We use Lee-Suzuki mappings and related techniques to construct effective two-body p-shell interactions and neutrinoless double-beta operators that exactly reproduce the results of large no-core-shell-model calculations of double-beta decay in nuclei with mass number A=6. We then apply the effective operators to the decay of nuclei with A=7, 8, and 10, again comparing with no-core calculations in much larger spaces. The results with the effective two-body operators are generally good. In some cases, however, they differ non-negligibly from the full no-core results, suggesting that three-body corrections to the decay operator in heavier nuclei may be important. An application of our procedure and related ideas to fp-shell nuclei such as 76Ge should be feasible within coupled-cluster theory.

Deepshikha Shukla; Jonathan Engel; Petr Navratil

2011-08-15T23:59:59.000Z

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.


421

X–rays from active galactic nuclei: relativistically broadened emission lines  

Science Journals Connector (OSTI)

...galactic nuclei: relativistically broadened emission lines A. C. Fabian Institute of Astronomy, University...many Seyfert 1 galaxies show an iron-K emission line. Some of these lines are broad and skew, reflecting the rapid motion of...

2002-01-01T23:59:59.000Z

422

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

NLE Websites -- All DOE Office Websites (Extended Search)

Summary: the atomic electric dipole moment especially in heavy nuclei is a sensitive test for CP- viloation... . Schematic layout of an advanced ISOL facility 1. 26 12;40 W...

423

Analytical expressions for the gate utilization factors of passive multiplicity counters including signal build-up  

SciTech Connect

In the realm of nuclear safeguards, passive neutron multiplicity counting using shift register pulse train analysis to nondestructively quantify Pu in product materials is a familiar and widely applied technique. The approach most commonly taken is to construct a neutron detector consisting of {sup 3}He filled cylindrical proportional counters embedded in a high density polyethylene moderator. Fast neutrons from the item enter the moderator and are quickly slowed down, on timescales of the order of 1-2 {micro}s, creating a thermal population which then persists typically for several 10's {micro}s and is sampled by the {sup 3}He detectors. Because the initial transient is of comparatively short duration it has been traditional to treat it as instantaneous and furthermore to approximate the subsequent capture time distribution as exponential in shape. With these approximations simple expressions for the various Gate Utilization Factors (GUFs) can be obtained. These factors represent the proportion of time correlated events i.e. Doubles and Triples signal present in the pulse train that is detected by the coincidence gate structure chosen (predelay and gate width settings of the multiplicity shift register). More complicated expressions can be derived by generalizing the capture time distribution to multiple time components or harmonics typically present in real systems. When it comes to applying passive neutron multiplicity methods to extremely intense (i.e. high emission rate and highly multiplying) neutron sources there is a drive to use detector types with very fast response characteristics in order to cope with the high rates. In addition to short pulse width, detectors with a short capture time profile are also desirable so that a short coincidence gate width can be set in order to reduce the chance or Accidental coincidence signal. In extreme cases, such as might be realized using boron loaded scintillators, the dieaway time may be so short that the build-up (thermalization transient) within the detector cannot be ignored. Another example where signal build-up might be observed is when a {sup 3}He based system is used to track the evolution of the time correlated signal created by a higher multiplying item within a reflective configuration such as the measurement of a spent fuel assembly. In this work we develop expressions for the GUFs which include signal build-up.

Croft, Stephen [Los Alamos National Laboratory; Evans, Louise G [Los Alamos National Laboratory; Schear, Melissa A [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

424

Experimental Particle Physics  

SciTech Connect

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

425

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

SciTech Connect

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

426

Active Diffusion of Motor Particles  

Science Journals Connector (OSTI)

The movement of motor particles consisting of one or several molecular motors bound to a cargo particle is studied theoretically. The particles move on patterns of immobilized filaments. Several patterns are described for which the motor particles undergo nondirected but enhanced diffusion. Depending on the walking distance of the particles and the mesh size of the patterns, the active diffusion coefficient exhibits three different regimes. For micrometer-sized motor particles in water, e.g., this diffusion coefficient can be enhanced by 2 orders of magnitude.

Stefan Klumpp and Reinhard Lipowsky

2005-12-23T23:59:59.000Z

427

Synthesis of transactinide nuclei in cold fusion reactions using radioactive beams  

SciTech Connect

Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out reactions) using radioactive beams are evaluated. Because in most of the cases intensities of radioactive beams are significantly less than those of the stable beams, reactions with the greatest radioactive-beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland [Phys. Rev. C 76, 014612 (2007)], who investigated the same nuclei.

Smolanczuk, Robert [Theoretical Physics Department, Soltan Institute for Nuclear Studies, Hoza 69, PL-00-681 Warszawa (Poland)

2010-06-15T23:59:59.000Z

428

Synthesis of transactinide nuclei in cold fusion reactions using radioative beams  

E-Print Network (OSTI)

Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out) reactions using radioactive beams are evaluated. Because intensities of radioactive beams are in most of the cases significantly lower than the ones of the stable beams, reactions with the highest radioactive beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland who investigated the same nuclei.

Smolanczuk, Robert

2009-01-01T23:59:59.000Z

429

Transverse polarization of $\\Lambda$ hyperons from quasi-real photoproduction on nuclei  

E-Print Network (OSTI)

The transverse polarization of $\\Lambda$ hyperons was measured in inclusive quasi-real 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.

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

2014-01-01T23:59:59.000Z

430

Synthesis of transactinide nuclei in cold fusion reactions using radioative beams  

E-Print Network (OSTI)

Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out) reactions using radioactive beams are evaluated. Because intensities of radioactive beams are in most of the cases significantly lower than the ones of the stable beams, reactions with the highest radioactive beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland who investigated the same nuclei.

Robert Smolanczuk

2009-12-04T23:59:59.000Z

431

Particle Data Group  

NLE Websites -- All DOE Office Websites (Extended Search)

About PDG About PDG About the PDG PDG authors Order PDG products PDG citation Encoder tools Job at LBNL Contact Us Downloads Resources Errata Archives Atomic Nuclear Properties Online HEP Info Non-PDG Databases Durham-RAL databases Current experiments Guide to Data Partial-wave analyses Contact Us News The "Reviews, Tables, Plots" section has been updated. The next book edition is due in early summer 2014, and the booklet in late summer 2014. Funded By: US DOE US NSF CERN MEXT (Japan) INFN (Italy) MEC (Spain) IHEP & RFBR (Russia) Mirrors: USA (LBNL) Brazil CERN Indonesia Italy Japan (KEK) Russia (Novosibirsk) Russia (Protvino) UK (Durham) The Review of Particle Physics J. Beringer et al. (Particle Data Group), Phys. Rev. D86, 010001 (2012) and 2013 partial update for the 2014 edition.

432

Particle Data Group - Authors  

NLE Websites -- All DOE Office Websites (Extended Search)

6 Edition and 2007 Web Update 6 Edition and 2007 Web Update (Click on Author Name to get Email address, phone numbers, etc.) RPP authors New authors of 2007 Web Update M. Antonelli, 102 H. Baer, 64 G. Bernardi, 103 M. Carena, 51 M.-C. Chen, 11 B. Dobrescu, 51 J.-F. Grivaz, 104 T. Gutsche, 105 J. Huston, 45 T. Junk, 51 C.-J. Lin, 1 H. Mahlke, 106 P. Mohr, 107 P. Nevski, 75 S. Rolli, 108 A. Romaniouk, 109 B. Seligman, 110 M. Shaevitz, 111 B. Taylor, 107 M. Titov, 56,112 G. Weiglein, 78 A. Wheeler, 69 Authors of the 2006 Review of Particle Physics W.-M. Yao et al. (Particle Data Group), J. Phys. G 33, 1 (2006) (bibtex format) Also see: PS format or PDF format. AUTHORS OF LISTINGS AND REVIEWS: (Click on Author Name to get Email address, phone numbers, etc.) RPP authors (RPP 2006)

433

Small Particles in Cirrus  

NLE Websites -- All DOE Office Websites (Extended Search)

Particles in Cirrus Particles in Cirrus Because the reflective properties of ice crystals in cirrus clouds can greatly influence the amount of solar energy that reaches the Earth, scientists use information about the shape and size of ice crystals as input to climate models. These data are obtained by satellite instruments, ground-based sensors, and research aircraft equipped with probes. However, notable discrepancies among these measurements have led to considerable uncertainty in how to represent these properties in climate models. From December 2009 through April 2010, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will sponsor the use of an instrumented aircraft to obtain the most comprehensive set of measurements of ice crystals in cirrus clouds yet obtained. In conjunction with

434

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

435

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

436

Relationship between Particle Mass and Mobility for Diesel Exhaust Particles  

Science Journals Connector (OSTI)

We used the aerosol particle mass analyzer (APM) to measure the mass of mobility-classified diesel exhaust particles. This information enabled us to determine the effective density and fractal dimension of diesel particles as a function of engine load. We ...

Kihong Park; Feng Cao; David B. Kittelson; Peter H. McMurry

2002-12-19T23:59:59.000Z

437

Charged Particle Radiography  

SciTech Connect

The Coulomb multiple scattering of charged particles as they pass through material allows them to be used as a radiographic probe. This forms the basis for a new kind of radiography that is finding application where conventional x-ray radiography is limited by flux or backgrounds. Charged-particle radiography is providing a versatile new probe that has advantages over conventional x-ray radiography for some unique application. Proton radiography has been used to make quantitative motion pictures of high explosive driven experiments and proves to be of great value for radiographing experiments that mock up nuclear weapon primaries for stockpile certification. By taking advantage of magnetic lens to magnify images and by using the very bright beams that can be made with electrons, charged-particle radiography may be useful for studying the fine spatial detail and very fast motion in laser driven implosion experiments at the National Ignition Facility. Finally, radiographs can be made using cosmic-ray muons for searching vehicles and cargo containers for surreptitious cargo of high z materials such as uranium or plutonium.

Morris, Chris (LANL) [LANL

2004-01-07T23:59:59.000Z

438

Movement of Indoor Fine Particle  

Science Journals Connector (OSTI)

For the pollution control of cleanroom, the airflow force is the most important ... important for the movement of indoor particles in cleanroom comparatively. As for the movement of particles...

Zhonglin Xu

2014-01-01T23:59:59.000Z

439

The ‘Oh my God’ particles  

Science Journals Connector (OSTI)

Every so often a particle from space hit’s Earth’s atmosphere with an energy exceeding anything that a manmade accelerator can achieve. Where do these particles come from? And how do they get to be so energeti...

Dr. Stephen Webb

2012-01-01T23:59:59.000Z

440

Collective Motions in Nuclei by the Method of Generator Coordinates  

Science Journals Connector (OSTI)

For an A-particle system, a trial wave function is constructed of the form ?(x1, ?, xA)=??(x1, ?, xA; ?)f(?)d?. The preliminary nucleonic wave function, ?, solves the problem in a "construction potential." This potential depends upon a "deformation parameter" or "generator coordinate," ?. The collective wave function, f(?), or "generator function," is folded into ? to produce a system wave function that depends only upon the coordinates, xi, of the particles. In the integration, the deformation parameters dissolve away. They do not appear in the final state function; they only generate it. No collective coordinates ever come into use nor do such coordinates ever have to be defined. In typical cases when the generator function contains one or more nodes, it generates nodes in the system wave function ? of the kind that describe collective kinetic energy. The energy of the system is extremized with respect to choice of the generator function, f(?). No Hamiltonian ever appears except the A-particle Hamiltonian. All nucleons are treated on the same basis whether in or above closed shells. The appropriate variational calculation leads to an integral equation or "generator wave equation" for f(?). This equation is solved in two limiting cases: the quadratic approximation, and the ?-function approximation. An analysis is made of the Peierls-Yoccoz procedure to calculate the effectivemass parameter in cases where the forces acting in the system are invariant with respect to translation or rotation. There is no external machinery to drive the construction potential. The effective inertia constant does not appear likely to agree in general with that calculated for the essentially different problem of particles in such a machine-driven potential, though the latter value is presumably more nearly correct for physical applications. The trial wave function in the method of generator coordinates is designed for simplicity, not for precision. It is applied in the following paper to the dilatational and shape oscillations of O16.

James J. Griffin and John A. Wheeler

1957-10-15T23:59:59.000Z

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.


441

E-Print Network 3.0 - angle-correlated particle-particle propagation...  

NLE Websites -- All DOE Office Websites (Extended Search)

INCLINED SURFACES USING SMOOTH Summary: -wise particle- particle interactions to simulate surface tension and contact line behavior. The pair-wise forces... a particle-particle...

442

Spin rotation and birefringence effect for a particle in a high energy storage ring and measurement of the real part of the coherent elastic zero-angle scattering amplitude, electric and magnetic polarizabilities  

E-Print Network (OSTI)

In the present paper the equations for the spin evolution of a particle in a storage ring are analyzed considering contributions from the tensor electric and magnetic polarizabilities of the particle. Study of spin rotation and birefringence effect for a particle in a high energy storage ring provides for measurement as the real part of the coherent elastic zero-angle scattering amplitude as well as tensor electric and magnetic polarizabilities. We proposed the method for measurement the real part of the elastic coherent zero-angle scattering amplitude of particles and nuclei in a storage ring by the paramagnetic resonance in the periodical in time nuclear pseudoelectric and pseudomagnetic fields.

V. G. Baryshevsky; A. A. Gurinovich

2005-06-14T23:59:59.000Z

443

THE EVOLUTION OF ACTIVE GALACTIC NUCLEI AND THEIR SPINS  

SciTech Connect

Massive black holes (MBHs), in contrast to stellar mass black holes, are expected to substantially change their properties over their lifetime. MBH masses increase by several orders of magnitude over a Hubble time, as illustrated by So?tan's argument. MBH spins also must evolve through the series of accretion and mergers events that increase the masses of MBHs. We present a simple model that traces the joint evolution of MBH masses and spins across cosmic time. Our model includes MBH-MBH mergers, merger-driven gas accretion, stochastic fueling of MBHs through molecular cloud capture, and a basic implementation of accretion of recycled gas. This approach aims at improving the modeling of low-redshift MBHs and active galactic nuclei (AGNs), whose properties can be more easily estimated observationally. Despite the simplicity of the model, it does a good job capturing the global evolution of the MBH population from z ? 6 to today. Under our assumptions, we find that the typical spin and radiative efficiency of MBHs decrease with cosmic time because of the increased incidence of stochastic processes in gas-rich galaxies and MBH-MBH mergers in gas-poor galaxies. At z = 0, the spin distribution in gas-poor galaxies peaks at spins 0.4-0.8 and is not strongly mass dependent. MBHs in gas-rich galaxies have a more complex evolution, with low-mass MBHs at low redshift having low spins and spins increasing at larger masses and redshifts. We also find that at z > 1 MBH spins are on average the highest in high luminosity AGNs, while at lower redshifts these differences disappear.

Volonteri, M.; Lasota, J.-P. [Institut d'Astrophysique de Paris, 98bis Bd. Arago, F-75014 Paris (France); Sikora, M. [Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warszawa (Poland); Merloni, A. [Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstr., D-85741 Garching (Germany)

2013-10-01T23:59:59.000Z

444

Apparatus for separating particles utilizing engineered acoustic contrast capture particles  

DOE Patents (OSTI)

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Kaduchak, Gregory (Los Alamos, NM); Ward, Michael D. (Los Alamos, NM)

2011-12-27T23:59:59.000Z

445

Apparatus for separating particles utilizing engineered acoustic contrast capture particles  

DOE Patents (OSTI)

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Kaduchak, Gregory; Ward, Michael D

2014-10-21T23:59:59.000Z

446

Hybrid Dissymmetrical Colloidal Particles  

Science Journals Connector (OSTI)

Centre de Recherche Paul Pascal, CNRS, 115, avenue du Dr Schweitzer, 33600 Pessac, France, Institut de Chimie de la Matière Condensée de Bordeaux, CNRS, 87, avenue du Dr Schweitzer, 33608 Pessac Cedex, France, Laboratoire de Chimie et Procédés de Polymérisation, CNRS?CPE Lyon, Bâtiment 308 F, 43, boulevard du 11 novembre 1918, BP 2077, 69616 Villeurbanne Cedex, France, and Laboratoire des IMRCP, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse Cedex, France ... After this step was completed, the suspension was transferred into a thermostated reactor and the monomer was introduced. ... On one hand, the resistance to some solvents of our hybrid particles could be improved cross-linking the polymer nodules. ...

Stéphane Reculusa; Céline Poncet-Legrand; Adeline Perro; Etienne Duguet; Elodie Bourgeat-Lami; Christophe Mingotaud; Serge Ravaine

2005-05-27T23:59:59.000Z

447

Study of Particle Resuspension by Impaction.  

E-Print Network (OSTI)

?? This thesis discusses particle resuspension from surfaces caused by particle impaction. The thesis also focuses on particle transport and different transport mechanisms regarding different… (more)

Hammersgård, Alexander

2011-01-01T23:59:59.000Z

448

THE SURVIVAL OF NUCLEI IN JETS ASSOCIATED WITH CORE-COLLAPSE SUPERNOVAE AND GAMMA-RAY BURSTS  

SciTech Connect

Heavy nuclei such as nickel-56 are synthesized in a wide range of core-collapse supernovae (CCSN), including energetic supernovae associated with gamma-ray bursts (GRBs). Recent studies suggest that jet-like outflows are a common feature of CCSN. These outflows may entrain synthesized nuclei at launch or during propagation, and provide interesting multi-messenger signals including heavy ultra-high-energy cosmic rays. Here, we investigate the destruction processes of nuclei during crossing from the stellar material into the jet material via a cocoon, and during propagation after being successfully loaded into the jet. We find that nuclei can survive for a range of jet parameters because collisional cooling is faster than spallation. While canonical high-luminosity GRB jets may contain nuclei, magnetic-dominated models or low-luminosity jets with small bulk Lorentz factors are more favorable for having a significant heavy nuclei component.

Horiuchi, Shunsaku; Murase, Kohta [Center for Cosmology and Astro-Particle Physics, Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210 (United States); Ioka, Kunihito [KEK Theory Center and Graduate University for Advanced Studies (Sokendai), Tsukuba 305-0801 (Japan); Meszaros, Peter [Department of Astronomy and Astrophysics, Department of Physics and Center for Particle Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States)

2012-07-01T23:59:59.000Z

449

The Universe Adventure - Fundamental Particles  

NLE Websites -- All DOE Office Websites (Extended Search)

Fundamental Particles Fundamental Particles Chart of Fundamental Particles All matter in the universe is comprised of fundamental particles. So what exactly makes up this matter? All matter is made of fundamental particles that came into being at the birth of the Universe. Quarks experience the strong force which is carried by massless particles called gluons. They bond together in specific combinations to form protons, neutrons, and other hadrons. Leptons do not experience the strong force but may interact via the electromagnetic force, the weak force, or both. Anti-quarks and anti-leptons are exactly the same as their quark and lepton counterparts, but have an opposite charge. All massive particles are influenced by the force of gravity. Quark-Gluon Plasma: 10-12 Seconds After the Big Bang

450

The assembly and calibration of a small animal whole-body counter utilizing ?b166?sholmium, ?b131?siodine, ?b186?srhenium, ?b153?ssamarium, and ?b99?s[superscript m]technetium  

E-Print Network (OSTI)

these radionuclides. For this reason a small animal whole-body counting system has been assembled and calibrated using the radionuclides '"Ho, "'I, '"Re, "'Sm, and " Tc for further research of the palliative treatment of small animals. The whole-body counting... for the Whole-body Counter 28 10 Re-186 Calibration Curve for the Whole-body Counter 28 11 Sm-153 Calibration Curve for the Whole-body Counter 29 12 Tc-99m Calibration Curve for the Whole-body Counter 29 13 Ho-166 Photopeak and FWHM 14 I-131 Photopeak...

Hulkovich, Paul Randolph

1991-01-01T23:59:59.000Z

451

Investigation Of The Magnetic Dipole Moments Of The I{pi}K = 1+1 States In The Even-Even Deformed Nuclei  

SciTech Connect

This study focuses on the investigation of the magnetic dipole moments of the excited I{pi}K = 1+1 states in the even-even deformed nuclei in the framework of the Quasi-particle Random Phase Approximation (QRPA). An analytic expression for the magnetic dipole moments of the states known to be generated by the isovector spin-spin forces is obtained. Using this analytic expression, the magnetic moments of the low-lying 1+ states for the 148,150Ce and 150,152Nd isotopes are also calculated numerically in the spectroscopic energy region. Furthermore, the reduced transition probabilities B(M1) and the lifetimes for each 1+ state are given.

Yakut, Hakan; Kuliev, Ali; Bektasoglu, Mehmet [Sakarya University, Department of Physics, Sakarya (Turkey); Guliyev, Ekber [Institute of Physics, National Academy of Sciences, Baku (Azerbaijan)

2007-04-23T23:59:59.000Z

452

The cluster-core model for halo-structure of light nuclei at the drip lines  

E-Print Network (OSTI)

Nuclei at both the neutron- and proton-drip lines are studied. In the cluster-core model, the halo-structure of all the observed and proposed cases of neutron- or proton-halos is investigated in terms of simple potential energy surfaces calculated as the sum of binding energies, Coulomb repulsion, nuclear proximity attraction and the centrifugal potential for all the possible cluster+core configurations of a nucleus. The clusters of neutrons and protons are taken to be unbound, with additional Coulomb energy added for proton-clusters. The model predictions agree with the available experimental studies but show some differences with the nucleon separation energy hypothesis, particularly for proton-halo nuclei. Of particular interest are the halo-structures of $^{11}N$ and $^{20}Mg$. The calculated potential energy surfaces are also useful to identify the new magic numbers and molecular structures in exotic nuclei. In particular, N=6 is a possible new magic number for very neutron-deficient nuclei, but Z=N=2 and Z=8 seem to remain magic even for such nuclei, near the drip line.

Raj K. Gupta; Sushil Kumar; M. Balasubramaniam; G. Munzenberg; Werner Scheid

2011-11-08T23:59:59.000Z

453

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

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

Ultrafine Diesel Tailpipe Particles ACES: Evaluation of Tissue Response to Inhaled 2007-Compliant Diesel Exhaust Pulmonary and Systemic Immune Response to Inhaled Oil Condensates...

454

The E(2) particle  

SciTech Connect

Recently it has been advocated [A. G. Cohen and S. L. Glashow, Phys. Rev. Lett. 97, 021601 (2006)] that for describing nature within the minimal symmetry requirement, certain subgroups of the Lorentz group may play a fundamental role. One such group is E(2) which induces a Lie algebraic noncommutative spacetime [M. M. Sheikh-Jabbari and A. Tureanu, Phys. Rev. Lett. 101, 261601 (2008); arXiv:0811.3670] where translation invariance is not fully maintained. We have constructed a consistent structure of noncommutative phase space for this system, and furthermore we have studied an appropriate point particle action on it. Interestingly, the Einstein dispersion relation p{sup 2}=m{sup 2} remains intact. The model is constructed by exploiting a dual canonical phase space following the scheme developed by us earlier [S. Ghosh and P. Pal, Phys. Rev. D 75, 105021 (2007)].

Ghosh, Subir; Pal, Probir [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700108 (India); Physics Department, Uluberia College, Uluberia, Howrah 711315 (India) and S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata-700098 (India)

2009-12-15T23:59:59.000Z

455

Theoretical Particle Astrophysics  

SciTech Connect

Abstract: Theoretical Particle Astrophysics The research carried out under this grant encompassed work on the early Universe, dark matter, and dark energy. We developed CMB probes for primordial baryon inhomogeneities, primordial non-Gaussianity, cosmic birefringence, gravitational lensing by density perturbations and gravitational waves, and departures from statistical isotropy. We studied the detectability of wiggles in the inflation potential in string-inspired inflation models. We studied novel dark-matter candidates and their phenomenology. This work helped advance the DoE's Cosmic Frontier (and also Energy and Intensity Frontiers) by finding synergies between a variety of different experimental efforts, by developing new searches, science targets, and analyses for existing/forthcoming experiments, and by generating ideas for new next-generation experiments.

Kamionkowski, Marc

2013-08-07T23:59:59.000Z

456

Particle Data Group - Authors  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle Data Group Associates and Advisors Particle Data Group Associates and Advisors Aguilar-Benitez, Amsler, Antonelli, Arguin, Armstrong, Artuso, Asner, Babu, Baer, Band, Barberio, Barnett, Battaglia, Bauer, Beringer, Bernardi, Bertl, Besson, Bichsel, Biebel, Bloch, Blucher, Blusk, Bunakov, Burchat, Cahn, Carena, Carone, Casas Serradilla, Casper, Cattai, Ceccucci, Chakraborty, Chen, Chivukula, Copic, Cousins, Cowan, Crawford, Dahl, Dalitz, D'Ambrosio, DeGouvea, DeGrand, Damour, Desler, Dissertori, Dobbs, Dobrescu, Donahue, Doser, Drees, Edwards,A, Edwards, Eidelman, Elvira, Erler, Ezhela, Fasso', Feng, Fetscher, Fields, Filimonov, Foster, Freedman, Froidevaux, Fukugita, Gaisser, Garren, Geer, Gerber, Gerbier, Gherghetta, Gibbons, Gilman, Giudice, Goldhaber, Goodman, Grab, Gritsan, Grivaz, Groom, Grünewald, Gurtu, Gutsche, Haber, Hagiwara, Hagmann, Hanhart, Harper , Hayes, Heltsley, Hernàndez-Rey, Hewett, Hikasa, Hinchliffe, Holder, Höcker, Hogan, Höhler, Holtkamp, Honscheid , Huston , Igo-Kemenes, Jackson, James, Jawahery, Johnson, Junk, Karlen, Kayser, Kirkby, Klein, Kleinknecht, Klempt, Knowles, Kolb, Kolda, Kowalewski, Kreitz, Kreps, Krusche, Kuyanov, Kwon, Lahav, Landua, Langacker , Lepage, Liddle, Ligeti, Lin, Liss, Littenberg, Liu, LoSecco, Lugovsky,K, Lugovsky,S, Lugovsky,V, Lynch, Lys, Mahlke, Mangano, Mankov, Manley, Mannel, Manohar, March-Russell, Marciano, Martin, Masoni, Matthews, Milstead, Miquel, Mönig, Mohr, Morrison, Murayama, Nakada, Nakamura, Narain, Nason, Navas, Nevski, Nicholson, Nir, Olive, Oyanagi, Pape, Patrignani, Peacock, Piepke, Porter, Prell, Punzi, Quadt, Quinn, Raby, Raffelt, Ratcliff, Razuvaev, Renk, Richardson, Roesler, Rolandi, Rolli, Romaniouk , Roos, Rosenberg, Rosner, Sachrajda, Sakai, Salam, Sanda, Sarkar, Sauli, Schaffner, Schindler, Schmitt, Schneider, Scott, Seligman, Shaevitz, Shrock, Silari, Skands, Smith, Sjöstrand, Smoot, Sokolosky, Spanier, Spieler, Spooner, Srednicki, Stahl, Stanev, Stone, Stone,S, Streitmatter, Sumiyoshi, Suzuki, Syphers, Tanabashi, Taylor, Terning, Titov, Tkachenko, Törnqvist, Tovey, Trilling, Trippe, Turner, Valencia, van Bibber, Vincter, Venanzoni, Vogel, Voss, Ward, Watari, Webber, Weiglein, Wells, Whalley, Wheeler, Wohl, Wolfenstein, Womersley, Woody, Workman, Yamamoto, Yao, Youssef, Zenin, Zhang, Zhu, Zyla

457

ARM - Measurement - Cloud ice particle  

NLE Websites -- All DOE Office Websites (Extended Search)

ice particle ice particle ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud ice particle Particles made of ice found in clouds. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments MET : Surface Meteorological Instrumentation Field Campaign Instruments REPLICATOR : Balloon-borne Ice Crystal Replicator CPI : Cloud Particle Imager CVI-AIR : Counterflow Virtual Impactor LEARJET : Lear Jet PARTIMG : Particle imager UAV-PROTEUS-MICRO : Proteus Cloud Microphysics Instruments

458

Particle Data Group - Errata 2012  

NLE Websites -- All DOE Office Websites (Extended Search)

2 Review of Particle Physics 2 Review of Particle Physics J. Beringer et al. (Particle Data Group), Phys. Rev. D86, 010001 (2012). During the time between editions of the Review of Particle Physics and the Particle Physics Booklet, we often find a number of errata. We correct most errata on our WWW pages. If you should find errata that are not known to us, please send mail to pdg @ lbl.gov. Pages 79, 1255 of the full Review (page 144 of the DataBooklet, pages 3, 3, 10 of the Web versions below): p, n, N-resonces; Baryons Summary Table (page 3) Baryons Summary Table (page 3) p Particle Listing (page 10) (November 28, 2012): The value of the partial mean life limit for n n → νe νe should read: > 1.4 (1030 years) at 90% CL. Page 320 of the full Review (page 4 of the Web versions below):

459

Giant quadrupole resonance in rotating light nuclei in the calcium region  

SciTech Connect

The quadrupole vibrations of rotating light nuclei around calcium are analyzed in the framework of the Fermi liquid drop model. The input parameters of shape and deformation are those obtained by the Mottelson-Nilsson method for the rotating light nuclei. The surface diffuseness and its changes with spin which could affect the giant resonances in the light nuclei are automatically taken care of in this method. The experimental energies of the giant quadrupole resonance are reproduced in the Fermi liquid drop model for the nonrotating case. The rotation produces the expected splitting of the giant quadrupole resonance modes with the appearance of soft modes. The nature of such splitting may explain the observed changes in the widths of giant resonances at high spins.

Shanmugam, G.; Ramamurthi, K.; Kamalaharan, B.

1986-07-01T23:59:59.000Z

460

Superheavy nuclei and quasi-atoms produced in collisions of transuranium ions  

SciTech Connect

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

Zagrebaev, V.I. [Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Moscow Region (Russian Federation); Oganessian, Yu.Ts.; Itkis, M.G. [Flerov Laboratory of Nuclear Reaction, JINR, Dubna (Russian Federation); Greiner, Walter [Frankfurt Institute for Advanced Studies, J.W. Goethe-Universitaet, Frankfurt (Germany)

2006-03-15T23:59:59.000Z

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.


461

Upper bounds on parity-violating ?-ray asymmetries in compound nuclei from polarized cold neutron capture  

Science Journals Connector (OSTI)

Parity-odd asymmetries in the electromagnetic decays of compound nuclei can sometimes be amplified above values expected from simple dimensional estimates by the complexity of compound nuclear states. Using a statistical approach, we estimate the root-mean-square of the distribution of expected parity-odd correlations s?n·k??, where s?n is the neutron spin and k?? is the momentum of the ?, in the integrated ? spectrum from the capture of cold polarized neutrons on Al, Cu, and In. We present measurements of the asymmetries in these and other nuclei. Based on our calculations, large enhancements of asymmetries were not predicted for the studied nuclei and the statistical estimates are consistent with our measured upper bounds on the asymmetries.

M. T. Gericke et al. (NPDGamma Collaboration)

2006-12-19T23:59:59.000Z

462

Building relativistic mean field models for finite nuclei and neutron stars  

E-Print Network (OSTI)

Background: Theoretical approaches based on density functional theory provide the only tractable method to incorporate the wide range of densities and isospin asymmetries required to describe finite nuclei, infinite nuclear matter, and neutron stars. Purpose: A relativistic energy density functional (EDF) is developed to address the complexity of such diverse nuclear systems. Moreover, a statistical perspective is adopted to describe the information content of various physical observables. Methods: We implement the model optimization by minimizing a suitably constructed chi-square objective function using various properties of finite nuclei and neutron stars. The minimization is then supplemented by a covariance analysis that includes both uncertainty estimates and correlation coefficients. Results: A new model, FSUGold2, is created that can well reproduce the ground-state properties of finite nuclei, their monopole response, and that accounts for the maximum neutron star mass observed up to date. In particul...

Chen, Wei-Chia

2014-01-01T23:59:59.000Z

463

Scaling of the F_2 structure function in nuclei and quark distributions at x>1  

E-Print Network (OSTI)

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for $x>1$, which is sensitive to short range contributions to the nuclear wave-function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the `super-fast' quarks probed at x>1. The falloff at x>1 is noticeably stronger in ^2H and ^3He, but nearly identical for all heavier nuclei.

N. Fomin; J. Arrington; D. B. Day; D. Gaskell; A. Daniel; J. Seely; R. Asaturyan; F. Benmokhtar; W. Boeglin; B. Boillat; P. Bosted; A. Bruell; M. H. S. Bukhari; M. E. Christy; E. Chudakov; B. Clasie; S. H. Connell; M. M. Dalton; D. Dutta; R. Ent; L. El Fassi; H. Fenker; B. W. Filippone; K. Garrow; 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; T. Miyoshi; H. Mkrtchyan; T. Navasardyan; G. Niculescu; Y. Okayasu; A. K. Opper; C. Perdrisat; D. H. Potterveld; V. Punjabi; X. Qian; P. E. Reimer; J. Roche; V. M. Rodriguez; O. Rondon; E. Schulte; 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

2010-08-16T23:59:59.000Z

464

Superdeformed structures and low $?$ parity doublet in Ne$-$S nuclei near neutron drip-line  

E-Print Network (OSTI)

The structure of Ne, Na, Mg, Al, Si, P and S nuclei near the neutron drip-line region is investigated in the frame-work of relativistic mean field theory and non-relativistic Skyrme Hartree-Fock formalism. The recently discovered nuclei $^{40}$Mg and $^{42}$Al, which are beyond the drip-line predicted by various mass formulae are located within these models. We find many largely deformed neutron-rich nuclei, whose structures are analyzed. From the structure anatomy, we find that at large deformation, low $\\Omega$ orbits of opposite parities (e.g. $\\frac{1}{2}^+$ and $\\frac{1}{2}^-$) occur close to each other in energy.

Shailesh K. Singh; S. K. Patra; C. R. Praharaj

2014-01-24T23:59:59.000Z

465

The structural evolution in transitional nuclei of mass 80 $\\leq$ A $\\leq$ 132  

E-Print Network (OSTI)

In this theoretical study, we report an investigation on the behavior of two neutron separation energy, differential variation of the separation energy and the abnormality in nuclear charge radius along the isotopic and isotonic chains of transition nuclei. We have used relativistic mean field formalism with NL3 and NL3$^*$ forces for this present analysis. The study refers to {\\it even-even} nuclei such as Zr, Mo, Ru and Pd with $N$ = 40$-$ 86, where a rich collective phenomena such as proton radioactivity, cluster or nucleus radioactivity, exotic shapes, {\\it Island of Inversion} and etc. are observed. These non-monotonic aspects over the isotopic chain are mainly correlated with the structural properties like shell/sub-shell closures, shape transition, clustering and magicity etc. In addition to these, we have shown the internal configuration of these nuclei to get a further insight into the reason for these discrepancies.

Bhuyan, M

2015-01-01T23:59:59.000Z

466

Janus and Multiblock Colloidal Particles  

Science Journals Connector (OSTI)

(5) Although Janus particles are named after the Roman god Janus with two faces, other ancient cultures also imagined two incompatible properties within a single unity. ... Our use of micrometer-size particles causes the range of interparticle forces, relative to particle size, to be much less than in some computer simulations;(40) this is considered to be a key aspect of the resulting self-assembly. ...

Qian Chen; Jing Yan; Jie Zhang; Sung Chul Bae; Steve Granick

2012-07-06T23:59:59.000Z

467

LINER/H II "Transition" Nuclei and the Nature of NGC 4569  

E-Print Network (OSTI)

Motivated by the discovery of young, massive stars in the nuclei of some LINER/H II ``transition'' nuclei such as NGC 4569, we have computed photoionization models to determine whether some of these objects may be powered solely by young star clusters rather than by accretion-powered active nuclei. The models were calculated with the photoionization code CLOUDY, using evolving starburst continua generated by the the STARBURST99 code of Leitherer et al. (1999). We find that the models are able to reproduce the emission-line spectra of transition nuclei, but only for instantaneous bursts of solar or higher metallicity, and only for ages of ~3-5 Myr, the period when the extreme-ultraviolet continuum is dominated by emission from Wolf-Rayet stars. For clusters younger than 3 Myr or older than 6 Myr, and for models with a constant star-formation rate, the softer ionizing continuum results in an emission spectrum more typical of H II regions. This model predicts that Wolf-Rayet emission features should appear in the spectra of transition nuclei. While such features have not generally been detected to date, they could be revealed in observations having higher spatial resolution. Demographic arguments suggest that this starburst model may not apply to the majority of transition nuclei, particularly those in early-type host galaxies, but it could account for some members of the transition class in hosts of type Sa and later. The starburst models during the Wolf-Rayet-dominated phase can also reproduce the narrow-line spectra of some LINERs, but only under conditions of above-solar metallicity and only if high-density gas is present (n_e >~ 10^5 cm^{-3}). This scenario could be applicable to some ``Type 2'' LINERs which do not show any clear signs of nonstellar activity.

A. J. Barth; J. C. Shields

2000-03-20T23:59:59.000Z

468

EMSL - Single Particle Laser Ablation  

NLE Websites -- All DOE Office Websites (Extended Search)

single-particle-laser-ablation en Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon http:...

469

High field gradient particle accelerator  

DOE Patents (OSTI)

A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications is disclosed. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle. 10 figs.

Nation, J.A.; Greenwald, S.

1989-05-30T23:59:59.000Z

470

High field gradient particle accelerator  

DOE Patents (OSTI)

A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

Nation, John A. (Ithaca, NY); Greenwald, Shlomo (Haifa, IL)

1989-01-01T23:59:59.000Z

471

Particle Physics at Discovery's Horizon  

NLE Websites -- All DOE Office Websites (Extended Search)

ideas and technologies of particle physics have entered the mainstream of society to transform the way we live. The production of superconducting magnets at the heart of MRI...

472

Vacuum friction in rotating particles  

E-Print Network (OSTI)

We study the frictional torque acting on particles rotating in empty space. At zero temperature, vacuum friction transforms mechanical energy into light emission and produces particle heating. However, particle cooling relative to the environment occurs at finite temperatures and low rotation velocities. Radiation emission is boosted and its spectrum significantly departed from a hot-body emission profile as the velocity increases. Stopping times ranging from hours to billions of years are predicted for materials, particle sizes, and temperatures accessible to experiment. Implications for the behavior of cosmic dust are discussed.

A. Manjavacas; F. J. García de Abajo

2010-09-21T23:59:59.000Z

473

High Temperature Falling Particle Receiver  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

(SNL) 8 Evaluate use of air recirculation in falling particle receiver to reduce heat loss and impacts of external wind - Prototype system constructed and modeled - Blower...

474

Stochastic pump of interacting particles  

E-Print Network (OSTI)

We consider the overdamped motion of Brownian particles, interacting via particle exclusion, in an external potential that varies with time and space. We show that periodic potentials that maintain specific position-dependent phase relations generate time-averaged directed current of particles. We obtain analytic results for a lattice version of the model using a recently developed perturbative approach. Many interesting features like particle-hole symmetry, current reversal with changing density, and system-size dependence of current are obtained. We propose possible experiments to test our predictions.

Debasish Chaudhuri; Abhishek Dhar

2010-12-28T23:59:59.000Z

475

CALIBRATION OF THE HB LINE ACTIVE WELL NEUTRON COINCIDENCE COUNTER FOR MEASUREMENT OF LANL 3013 HIGHLY ENRICHED URANIUM PRODUCT SPLITS  

SciTech Connect

In this paper we describe set-up, calibration, and testing of the F-Area Analytical Labs active well neutron coincidence counter(HV-221000-NDA-X-1-DK-AWCC-1)in SRNL for use in HB-Line to enable assay of 3013EU/Pu metal product. The instrument was required within a three-month window for availability upon receipt of LANL Category IV uranium oxide samples into the SRS HB-Line facility. We describe calibration of the instrument in the SRNL nuclear nondestructive assay facility in the range 10-400 g HEU for qualification and installation in HB-Line for assay of the initial suite of product samples.

Dewberry, R; Donald02 Williams, D; Rstephen Lee, R; David-W Roberts, D; Leah Arrigo, L

2008-01-22T23:59:59.000Z

476

Apparatus And Method For Reducing Drag Of A Bluff Body In Ground Effect Using Counter-Rotating Vortex Pairs  

DOE Patents (OSTI)

An aerodynamic base drag reduction apparatus and method for bluff bodies, such as tractor-trailer trucks, utilizing a pair of lift surfaces extending to lift surface tips and located alongside the bluff body such as on opposing left and right side surfaces. In a flowstream substantially parallel to the longitudinal centerline of the bluff body, the pair of lift surfaces generate a pair of counter-rotating trailing vortices which confluence together in the wake of the bluff body in a direction orthogonal to the flowstream. The confluence draws or otherwise turns the flowstream, such as the flowstream passing over a top surface of the bluff body, in and around behind a trailing end of the bluff body to raise the pressure on a base surface at the trailing end and thereby reduce the aerodynamic base drag.

Ortega, Jason M. (Pacifica, CA); Salari, Kambiz (Livermore, CA)

2005-08-09T23:59:59.000Z

477

Apparatus And Method For Reducing Drag Of A Bluff Body In Ground Effect Using Counter-Rotating Vortex Pairs  

DOE Patents (OSTI)

An aerodynamic base drag reduction apparatus and method for bluff bodies, such as tractor-trailer trucks, utilizing a pair of lift surfaces extending to lift surface tips and located alongside the bluff body such as on opposing left and right side surfaces. In a flowstream substantially parallel to the longitudinal centerline of the bluff body, the pair of lift surfaces generate a pair of counter-rotating trailing vortices which confluence together in the wake of the bluff body in a direction orthogonal to the flowstream. The confluence draws or otherwise turns the flowstream, such as the flowstream passing over a top surface of the bluff body, in and around behind a trailing end of the bluff body to raise the pressure on a base surface at the trailing end and thereby reduce the aerodynamic base drag.

Ortega, Jason M. (Pacifica, CA); Sabari, Kambiz (Livermore, CA)

2005-12-27T23:59:59.000Z

478

Symmetry-dictated trucation: Solutions of the spherical shell model for heavy nuclei  

SciTech Connect

Principles of dynamical symmetry are used to simplify the spherical shell model. The resulting symmetry-dictated truncation leads to dynamical symmetry solutions that are often in quantitative agreement with a variety of observables. Numerical calculations, including terms that break the dynamical symmetries, are shown that correspond to shell model calculations for heavy deformed nuclei. The effective residual interaction is simple, well-behaved, and can be determined from basic observables. With this approach, we intend to apply the shell model in systematic fashion to all nuclei. The implications for nuclear structure far from stability and for nuclear masses and other quantities of interest in astrophysics are discussed.

Guidry, M.W. [Tennessee Univ., Knoxville, TN (United States). Dept. of Physics]|[Oak Ridge National Lab., TN (United States)

1992-12-31T23:59:59.000Z

479

Searches for proton radioactivity in odd Z drip-line nuclei from Z=61 to 67  

Science Journals Connector (OSTI)

Beams of 185–204 MeV Ca40 ions have been used to bombard Mo92, Ru96, Pd102, and Cd106 targets in order to produce the proton-decay candidate nuclei Pm128, Eu132, Tb138, and Ho142 via the 1p3n fusion evaporation channel. In each case no evidence for proton radioactivity was found. On the basis of mass model systematics it was concluded that the odd proton is not sufficiently unbound in these nuclei for proton emission to compete successfully with ? decay.

K. Livingston; P. J. Woods; T. Davinson; N. J. Davis; A. N. James; R. D. Page; P. J. Sellin; A. C. Shotter

1993-12-01T23:59:59.000Z

480

Isolation and partial characterization of the nuclei of the unicellular marine alga Olisthodiscus luteus  

E-Print Network (OSTI)

) Sherri Sutton Symank, B. S. , Texas AQf University Chariman of Advisory Committee: Dr. P. J. Rizzo The development of a nuclear isolation procedure for nuclei from Olisthodiscus luteus is described. Several parameters of the isola-' tion medium were... varied in order to obtain maximum purity and yield of nuclei. Selection of optimal conditions was made on the basis of nuclear yield, RNA/DNA ratios, and light microscopy. The final iso- lation medium contained 1. 0 M hexylene glycol, 1. 0 mM CaC12, 1...

Symank, Sherri Sutton

2012-06-07T23:59:59.000Z

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.


481

Symmetry energy of hot nuclei in the relativistic Thomas-Fermi approximation  

E-Print Network (OSTI)

We develop a self-consistent description of hot nuclei within the relativistic Thomas--Fermi approximation using the relativistic mean-field model for nuclear interactions. The temperature dependence of the symmetry energy and other physical quantities of a nucleus are calculated by employing the subtraction procedure in order to isolate the nucleus from the surrounding nucleon gas. It is found that the symmetry energy coefficient of finite nuclei is significantly affected by the Coulomb polarization effect. We also examine the dependence of the results on nuclear interactions and make a comparison between the results obtained from relativistic and nonrelativistic Thomas-Fermi calculations.

Zhang, Z W; Hu, J N; Shen, H

2014-01-01T23:59:59.000Z

482

The energy dependence of the electric dipole strength in heavy nuclei  

E-Print Network (OSTI)

On the basis of new photon scattering measurements and a reevaluation of average neutron resonance capture data we investigate how well Lorentzians adjusted to photo-neutron data in the giant dipole resonances give a good description of the photon strength also below the neutron threshold. If deformation effects are properly taken into account this is verified down to about 5 MeV for various nuclei with A>80 such that the previously employed differentiation between deformed and non-deformed nuclei is no longer necessary.

Eckart Grosse; Frantisek Becvar; Arnd R. Junghans; Gencho Rusev; Ronald Schwengner; Andreas Wagner

2008-10-10T23:59:59.000Z

483

A description of the paraventricular and supraoptic nuclei of the bovine hypothalamus  

E-Print Network (OSTI)

. Brettscbneider (19S4) observed the eccentric lecatioa of the nucleus vithin ths supreoptic and paraventriculsr nuclei of the horse. He casqssred tbe cells to those of Clsrhe's col~ of the spinel cord snd to cells undergoing degeneration. Vcn Vier ling (1956.... Brettscbneider (19S4) observed the eccentric lecatioa of the nucleus vithin ths supreoptic and paraventriculsr nuclei of the horse. He casqssred tbe cells to those of Clsrhe's col~ of the spinel cord snd to cells undergoing degeneration. Vcn Vier ling (1956...

Talukdar, Amir Hussain

2012-06-07T23:59:59.000Z

484

Short Range Correlations in Nuclei at Large xbj through Inclusive Quasi-Elastic Electron Scattering  

SciTech Connect

The experiment, E08-014, in Hall-A at Jefferson Lab aims to study the short-range correlations (SRC) which are necessary to explain the nuclear strength absent in the mean field theory. The cross sections for 2H, 3He, 4He, 12C, 40Ca and 48Ca, were measured via inclusive quasi-elastic electron scattering from these nuclei in a Q2 range between 0.8 and 2.8 (GeV/c)^2 for x>1. The cross section ratios of heavy nuclei to 2H were extracted to study two-nucleon SRC for 1

Ye, Zhihong [UVA

2013-12-01T23:59:59.000Z

485

Parametrization of light nuclei quasiparticle energy shifts and composition of warm and dense nuclear matter  

E-Print Network (OSTI)

Correlations and the formation of bound states (nuclei) are essential for the properties of nuclear matter in equilibrium as well as in nonequilibrium. In a quantum statistical approach, quasiparticle energies are obtained for the light elements that reflect the influence of the medium. We present analytical fits for the quasiparticle energy shifts of light nuclei that can be used in various applications. This is a prerequisite for the investigation of warm and dense matter that reproduces the nuclear statistical equilibrium and virial expansions in the low-density limit as well as relativistic mean field and Brueckner Hartree-Fock approaches near saturation density.

G. Röpke

2011-01-24T23:59:59.000Z

486

Unlike-particle collision operator for gyrokinetic particle simulations  

Science Journals Connector (OSTI)

Plasmas in modern tokamak experiments contain a significant fraction of impurity ion species in addition to main deuterium background. A new unlike-particle collision operator for @df particle simulation has been developed to self-consistently study ... Keywords: Gyrokinetics, Magnetized plasmas, Plasma kinetic equations

R. A. Kolesnikov; W. X. Wang; F. L. Hinton

2010-08-01T23:59:59.000Z

487

Section of Particle Physics http://www.particle.kth.se  

E-Print Network (OSTI)

outstanding educational value ­ nature has provided us with a free source of high energy subatomic particles! Already at SCFAB there is a student laboratory exercise in which cosmic ray muons are brought to rest cosmic ray detectors in order to study showers of particles produced when high energy primary cosmic rays

Haviland, David