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Superdeformations and fermion dynamical symmetries

Description: In this talk, I will present a link between nuclear collective motions and their underlying fermion dynamical symmetries. In particular, I will focus on the microscopic understanding of deformations. It is shown that the SU{sub 3} of the one major shell fermion dynamical symmetry model (FDSM) is responsible for the physics of low and high spins in normal deformation. For the recently observed phenomena of superdeformation, the physics of the problem dictates a generalization to a supershell str… more
Date: January 1, 1990
Creator: Wu, Cheng-Li (Drexel Univ., Philadelphia, PA (USA). Dept. of Physics and Atmospheric Science Tennessee Univ., Knoxville, TN (USA). Dept. of Physics and Astronomy Joint Inst. for Heavy Ion Research, Oak Ridge, TN (USA))
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Partner: UNT Libraries Government Documents Department
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An aerial radiological survey of Technical Areas 2, 21, and 53 and surroundings, Los Alamos National Laboratory, Los Alamos, New Mexico

Description: An aerial radiological survey of the entire Los Alamos National Laboratory was flown in September 1982. The data from a part of the survey, Technical Areas 2, 21, and 53, are presented here along with pertinent data from an October 1975 survey of limited areas of Los Alamos. The data from Technical Area 15, another part of the survey, will be published in another report. Contour maps of the gamma survey data show some Cs-137 activity in Los Alamos Canyon as well as in DP Canyon beside TA-21. So… more
Date: September 1, 1990
Creator: Fritzsche, A.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A technique for shell compression measurements of laser fusion targets by neutron activation of a rubidium tracer

Description: At the Nova Laser, the activation of a rubidium tracer incorporated in the shell of ICF targets has become a standard diagnostic technique for measuring the compressed shell areal density {l angle}{rho}{Delta}R{r angle}. The isotope {sup 85}Rb is activated by 14 MeV implosion neutrons to produce the isomer {sup 84m}Rb(t{sub {1/2}} = 20.5 min) which is used to determine the shell {l angle}{rho}{Delta}R{r angle} while the radioactive isotope {sup 86}Rb(t{sub 1/2} = 18.8 d) is used to determine th… more
Date: December 7, 1990
Creator: Lane, S.M. & Nelson, M.B.
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Partner: UNT Libraries Government Documents Department
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Study of multiparticle jet production using calorimeters, high energy channeling, and other high energy physics research

Description: During this period, work was started on the construction of the backward gamma chambers to be used in experiment E683 at Fermilab. Work also is proceeding on various auxiliary experiments that can be performed with the experimental set-up. Work on the SSC accelerator and experiments began in 1984 with the participation of the principal investigator in the Snomass summer studies and continues with the funding of the accelerator and the location of its site in Texas. We are working with the large… more
Date: October 1, 1990
Creator: Kanofsky, A. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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sup 176 Lu: An unreliable s-process chronometer

Description: A level scheme of {sup 176}Lu up to {approximately}1400 keV excitation energy is deduced from a gamma-gamma coincidence experiment and previously published particle transfer data. 170 gamma-ray transitions are placed between 85 levels, confirming many of the previously established levels and some of the decay scheme. A level at 835.5 keV (J{sup {pi}} = 5{sup {minus}}, t{sub 1/2} < 10 ns) decays with substantial strength to both the ground state (7{sup {minus}}, 4.08 {times} 10{sup 10} yr) and t… more
Date: November 1, 1990
Creator: Lesko, K.T.; Norman, E.B.; Larimer, R.M. & Sur, B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An alpha/beta/gamma health physics instrument with pulse-shape discrimination

Description: A recent breakthrough in alpha scintillation detector design supports the feasibility of extending this new technology to the development of a monolithic alpha/beta/gamma ({alpha}/{beta}/{gamma}) scintillation detector. The new scintillator is physically robust and chemically resistant to environmental conditions encountered in radiation monitoring, and yet inexpensive to manufacture. The use of pulse-shape discrimination electronics allows pulses from each scintillator to be separated for part… more
Date: January 1, 1990
Creator: McElhaney, S. A.; Chiles, M. M. & Ramsey, J. A.
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Partner: UNT Libraries Government Documents Department
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The Gammasphere

Description: GAMMASPHERE is one of a new generation of gamma ray detector arrays. It consists of 110 Compton-suppressed large volume Ge detectors. The design goal is to achieve high efficiency and peak-to-total value for four to five fold coincidence experiments. Such highfold coincidence capability will provide new physics opportunities in areas such as high spins, transfer reactions, giant resonances, and astrophysics. The design of the detector and shield has been developed through extensive simulation c… more
Date: January 1, 1990
Creator: Lee, I-Yang.
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Partner: UNT Libraries Government Documents Department
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Status of soft photons in experiment E855

Description: Experiment E855 was carried out at the AGS at Brookhaven National Laboratory to study soft photon production near center of mass rapidity Y{sub cm} {approximately} 0 in proton-nucleus collisions at 10 at 18 GeV/c. This was the first dedicated experiment to study this phenomenon at these lower energies. It is important to note that the related process of low mass dilepton pair production has been studied extensively at these energies and an excess signal of dileptons above known hadronic backgro… more
Date: January 1, 1990
Creator: Woody, C.; Lissauer, D. (Brookhaven National Lab., Upton, NY (USA)); Gomez del Campo, J.; Ray, A.; Shapira, D.; Tincknell, M. (Oak Ridge National Lab., TN (USA)) et al.
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Partner: UNT Libraries Government Documents Department
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High resolution inelastic gamma-ray measurements with a white neutron source from 1 to 200 MeV

Description: Measurements of prompt gamma rays following neutron-induced reactions have recently been made at the spallation neutron source at the WNR target area of LAMPF using germanium detectors. These experiments provide extensive excitation function data for inelastic neutron scattering as well as for other reactions such as (n,{alpha}), (n,n{alpha}), (n,p), (n,np), (n,nnp) and (n,xn) for 1 {le} {times} {le} 11. The continuous energy coverage available from 1 MeV to over 200 MeV is ideal for excitation… more
Date: January 1, 1990
Creator: Nelson, R. O.; Laymon, C. M. & Wender, S. A.
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Partner: UNT Libraries Government Documents Department
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JASA: A prototype water- C erenkov air-shower detector

Description: A small pilot experiment to examine the use of the water-Cerenkov technique for air shower detection was installed near the center of the CYGNUS air shower array. Preliminary results showing general agreement with simulations are presented. Thus, the technique promises to offer significant advances for VHE-UHE {gamma}-ray astronomy. 5 refs., 4 figs.
Date: January 1, 1990
Creator: Berley, D.; Dion, C.; Goodman, J. A.; Haines, T. J.; Kwok, P. W.; Stark, M. J. et al.
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Partner: UNT Libraries Government Documents Department
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The design and installation of a core discharge monitor for CANDU-type reactors

Description: A new type of surveillance systems that monitors neutron and gamma radiation in a reactor containment is being installed at the Ontario Hydro Darlington Nuclear Generating Station A, Unit 2. Unlike video or film surveillance that monitors mechanical motion, this system measures fuel-specific radiation emanating from irradiated fuel as it is pushed from the core of CANDU-type reactors. Proof-of-principle measurements have been carried out at Bruce Nuclear Generating Station A, Unit 3. The system… more
Date: January 1, 1990
Creator: Halbig, J.K. (Los Alamos National Lab., NM (USA)); Monticone, A.C.; Ksiezak, L. (International Atomic Energy Agency, Vienna (Austria)) & Smiltnieks, V. (International Atomic Energy Agency, Toronto, ON (Canada). Regional Office)
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Partner: UNT Libraries Government Documents Department
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Criticality assessment of TRU burial ground culverts

Description: An effort to assess the criticality risks of {sup 239}Pu in TRU Burial Ground Culverts has been underway for several years. The concern arose from discrepancies in two types of monitors that have been used to assay the {sup 239}Pu waste prior to storage in 55-gallon drums that are placed in the culverts. One type is the solid waste monitor (SWM), which is based on gamma-ray measurements; the other is the neutron coincidence monitor, which is based on neutron measurements. The NCC was put into r… more
Date: September 26, 1990
Creator: Winn, W. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Gamma-ray production cross section measurements using a white neutron source from 1 to 400 MeV

Description: The continuous energy (white) neutron source at the Los Alamos Meson Physics Facility (LAMPF) is used to measure photon-production cross sections over a wide range of neutron energies. Detector systems have been or are being developed to measure gamma rays in the energy range from hundreds of keV up to several hundreds of MeV. In particular a high resolution Ge detector system is used to detect gamma rays from several hundred keV to over 6 MeV. A 5 crystal BGO detector system is used for measur… more
Date: January 1, 1990
Creator: Wender, S. A.; Nelson, R. O. & Laymon, C. M.
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Partner: UNT Libraries Government Documents Department
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Recent experiences of scrap and waste assay using neutron coincidence counting of materials from F B-Line at the Savannah River Site

Description: The heterogeneous nature of scrap and waste poses unique problems for quantitative measurement. This is particularly true when the sample to be measured can have significant amounts of plutonium in addition to a variety of matrix components. One approach to addressing these difficulties is to combine gamma-ray and neutron counting techniques. A system combining a segmented gamma-ray scanner and neutron coincidence counter has recently been developed for the non-destructive assay of plutonium-be… more
Date: January 1, 1990
Creator: Baker, L.; MacMurdo, K. (Westinghouse Savannah River Co., Aiken, SC (USA)); Miller, M. C. & Bosler, G. E. (Los Alamos National Lab., NM (USA))
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Partner: UNT Libraries Government Documents Department
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Cross sections for production of 70 discrete-energy gamma rays created by neutron interactions with sup 56 Fe for E sub n to 40 MeV: Tabulated data

Description: Inelastic and nonelastic neutron interactions with {sup 56}Fe have been studied for incident neutron energies between 0.8 and 41 MeV. An iron sample isotopically enriched in the mass 56 isotope was used. Gamma rays representing 70 transitions among levels in residual nuclei were identified, and production cross sections were deduced. The reactions studied were {sup 56}Fe(n,n{prime}){sup 56}Fe, {sup 56}Fe(n,p){sup 56}Mn, {sup 56}Fe(n,2n){sup 55}Fe, {sup 56}Fe(n,d + n,np){sup 55}Mn, {sup 56}Fe(n,… more
Date: September 1, 1990
Creator: Dickens, J.K.; Todd, J.H. & Larson, D.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The initiation of excess power and possible products of nuclear interactions during the electrolysis of heavy water

Description: The electrolysis of heavy water is being investigated with an insulated flow calorimetric system. The electrolyte was 0.1 to 1.0 N LiOD in D{sub 2}O and cylindrical palladium cathodes surrounded by wire-wound platinum anodes have been used at cathode current densities of 100 to 800 mA/cm{sup 2}. The most recent test has been made with a closed system'' without off-gal in which the electrolysis gases were internally recombined. Fast neutrons and gamma rays were measured continuously during the t… more
Date: January 1, 1990
Creator: Scott, C. D.; Mrochek, J. E.; Scott, T. C.; Michaels, G. E.; Newman, E. & Petek, M.
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Partner: UNT Libraries Government Documents Department
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Measurements of 1/f noise in A-Si:H pin diodes and thin-film-transistors

Description: We measured the equivalent noise charge of a-Si:H pin diodes (5 {approximately} 45{mu}m i-layer) with a pulse shaping time of 2.5 {mu}sec under reverse biases up to 30 V/{mu}m and analyzed it as a four component noise source. The frequency spectra of 1/f noise on the soft-breakdown region and of the Nyquist noise from contact resistance of diodes were measured. Using the conversion equations for a CR-RC shaper, we identified the contact resistance noise and the 1/f noise as the main noise sourc… more
Date: May 1, 1990
Creator: Cho, Gyuseong; Drewery, J. S.; Fujieda, I.; Jing, T.; Kaplan, S. N.; Perez-Mendez, V. et al.
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Partner: UNT Libraries Government Documents Department
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1990 yearly calibration of Pacific Northwest Laboratory's gross-gamma borehole geophysical logging system

Description: This report describes the 1990 yearly calibration of a gross-gamma geophysical pulse logging system owned by the US Department of Energy (DOE) and operated by Pacific Northwest Laboratory (PNL). The calibration was conducted to permit the continued use of this system for geological and hydrologic studies associated with remedial investigation at the Hanford Site. Primary calibrations to equivalent uranium units were conducted in borehole model standards that were recently moved to the Hanford S… more
Date: August 1, 1990
Creator: Arthur, R.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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(Test, calibrate, and prepare a BGO photon detector system)

Description: The traveler spent the year at CERN primarily to test, calibrate, and prepare a BGO photon detector system for use in the August 1990 run of WA80 with sulfur beams and for use in future planned runs with an expanded BGO detector. The BGO was used in test-beam runs in December 1989 and April--May 1990 and in the August data-taking run. The Midrapidity Calorimeters (MIRAC) were also prepared in a new geometry for the August run with a new transverse energy trigger. The traveler also continued to … more
Date: October 19, 1990
Creator: Awes, T.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Neutron-proton bremsstrahlung studies using the white neutron source at the LAMPF/WNR

Description: Nucleon-nucleon bremsstrahlung is a few-body radiative process that provides insight into several areas of nuclear physics. It is one of the simplest systems for studying the off-shell behavior of the nucleon-nucleon potential. The physics involved in neutron-proton bremsstrahlung (NPB) is significantly different from that of proton-proton bremsstrahlung (PPB). In particular, NPB cross sections are much larger than PPB cross sections because NPB allows E1 radiation, and the contribution to the … more
Date: January 1, 1990
Creator: Wender, S. A.; Nelson, R. O.; Schillaci, M. E. (Los Alamos National Lab., NM (USA)) & Blann, M. (Lawrence Livermore National Lab., CA (USA))
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Partner: UNT Libraries Government Documents Department
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Proof-of-principle measurements for an NDA-based core discharge monitor

Description: The feasibility of using nondestructive assay instruments as a core discharge monitor for CANDU reactors was investigated at the Ontario Hydro Bruce Nuclear Generating Station A, Unit 3, in Ontario, Canada. The measurements were made to determine if radiation signatures from discharged irradiated fuel could be measured unambiguously and used to count the number of fuel pushes from a reactor face. Detectors using the ({gamma},n) reaction thresholds of beryllium and deuterium collected the data, … more
Date: January 1, 1990
Creator: Halbig, J. K. (Los Alamos National Lab., NM (USA)) & Monticone, A. C. (International Atomic Energy Agency, Vienna (Austria))
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Partner: UNT Libraries Government Documents Department
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Monte Carlo simulation of gamma ray scanning gauge

Description: A gamma ray scanning gauge was simulated with Monte Carlo to study the properties of gamma scanning gauges and to resolve the counts coming from a {sup 235}U source from those coming from a contaminant ({sup 232}U) whose daughters emit high energy gamma rays. The simulation has been used to infer the amount of the {sup 232}U contaminant in a {sup 235}U source to select the best size for the NaI(Tl) detector crystal to minimize the effect of the contaminant. The results demonstrate that Monte Ca… more
Date: December 31, 1990
Creator: Hartfield, G. L.; Freeman, L. B.; Dei, D. E.; Emert, C. J.; Glickstein, S. S.; Kahler, A. C. et al.
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Partner: UNT Libraries Government Documents Department
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A low threshold EAS (extensive-air-shower) array for gamma-ray astronomy at Los Alamos

Description: A new type of extensive-air-shower (EAS) array is described that achieves a low energy threshold, large area, high duty factor and large muon coverage. By placing a regularly-spaced grid of phototubes just below the surface of a shallow pond, the Cherenkov light of particles in an air shower striking the water can be detected, resulting in a primary energy threshold of less than 1 TeV. This highly sensitive array can thus be used to span the gap of information between the existing air Cherenkov… more
Date: January 1, 1990
Creator: Burman, R. L.; Hoffman, C. M.; Nagle, D. E.; Potter, M. E.; Sandberg, V.; Berley, D. et al.
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Partner: UNT Libraries Government Documents Department
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Radioactive targets for nuclear astrophysics research at LANSCE

Description: During the past few years we have made measurements of (n,p) and (n,{alpha}) cross sections on several radioactive nuclei of importance to nuclear astrophysics. The measurements were made at the Manuel Lujan, Jr., Neutron Scattering Center (LANSCE) from thermal neutron energy to approximately 100 keV. Successful measurements have been completed on the radioisotopes {sup 7}Be, {sup 22}Na and {sup 36}Cl while preliminary data have been taken on targets of {sup 54}Mn and {sup 55}Fe. Similar measur… more
Date: January 1, 1990
Creator: Koehler, Paul E.; O'Brien, Hal A. & Gursky, Judy C.
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Partner: UNT Libraries Government Documents Department
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