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Overview of reaction mechanisms for calculating the high energy component of fast-nucleon induced gamma spectra

Description: This presentation reviews the current status of quantum mechanical models for understanding the high-energy component of gamma spectra resulting from radiative capture of fast nucleons; i.e., the part of the spectrum that is not amenable to standard statistical model (Hauser-Feshbach) treatments. These models are based on the direct-semidirect (DSD) model and its variants. Included are recent results on the extension of the DSD model to unbound final states, a discussion of problems and improve… more
Date: February 21, 1995
Creator: Dietrich, F.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spectral gamma-ray logging for the 100-N Area, Hanford, Washington

Description: The objective of this effort was to delineate the vertical distribution and concentration of anthropogenic radionuclides in the subsurface surrounding nine boreholes in the 100-N Area available for geophysical logging with the Radionuclide Logging System (RLS). Cesium was defined in eight boreholes, and the ninth hole was found to not contain any such radionuclides.
Date: October 2, 1996
Creator: Szwartz, G.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Thermal-neutron capture in light nuclei

Description: We have made considerable progress toward the goal of carrying out thermal-neutron capture {gamma}-ray measurements on all stable isotopes below A=60. Information processed till now has significantly augmented the existing knowledge on the detailed nuclear level structure of many light nuclides. Most of this knowledge comes from our {gamma}-ray energies, level placements, and branching ratios of secondary transitions between low-lying states. Spectroscopic information is also contained in the c… more
Date: October 1, 1996
Creator: Raman, S.; Jurney, E. T. & Lynn, J. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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PC/FRAM, Version 3.2 User Manual

Description: This manual describes the use of version 3.2 of the PC/FRAM plutonium isotopic analysis software developed in the Safeguards Science and Technology Group, NE-5, Nonproliferation and International Security Division Los Alamos National Laboratory. The software analyzes the gamma ray spectrum from plutonium-bearing items and determines the isotopic distribution of the plutonium 241Am content and concentration of other isotopes in the item. The software can also determine the isotopic distribution … more
Date: February 23, 1999
Creator: Kelley, T. A. & Sampson, T. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Extended direct semidirect mechanism and the role of multistep processes in fast nucleon radiative capture

Description: We have recently developed an extension of the direct-semidirect (DSD) radiative capture model to unstable final states and have confirmed its utility in explaining the spectrum of rays from capture of polarized 19.6-MeV protons on {sup 89}Y. It was found that the extended DSD model, supplemented by a Hauser-Feshbach contribution, successfully explains the observed spectra, angular distributions, and analyzing powers, without requiring additional mechanisms, such as precompound or multistep emi… more
Date: May 1, 1997
Creator: Dietrich, F.S.; Chadwick, M.B. & Kerman, A.K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The {alpha}-induced thick-target {gamma}-ray yield from light elements

Description: The {alpha}-induced thick-target {gamma}-ray yield from light elements has been measured in the energy range 5.6 MeV {le} E{sub {alpha}} {le} 10 MeV. The {gamma}-ray yield for > 2.1 MeV from thick targets of beryllium, boron nitride, sodium fluoride, magnesium, aluminum and silicon were measured using the {alpha}-particle beam from the Lawrence Berkeley Laboratories 88 in. cyclotron. The elemental yields from this experiment were used to construct the {alpha}-induced direct production {gamma}-r… more
Date: October 1994
Creator: Heaton, R. K.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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A method to improve spectral resolution in planar semiconductor gamma-ray detectors

Description: This paper describes an empirically derived algorithm to compensate for charge trapping in CdTe, CdZnTe, and other planar semiconductor detectors. The method is demonstrated to be an improvement over available systems and application to experimental data is shown.
Date: May 1, 1995
Creator: Keele, B. D.; Addleman, R. S. & Troyer, G. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The quasi-continuum of gamma rays following the decay of superdeformed bands in the Hg region

Description: The quasi-continuum of the spectrum associated with the decay-out of the yrast superdeformed band in {sup 194}Hg has been extracted. It has for the first time been possible to compare the spin and excitation energy determined from the analysis of the quasi-continuum {gamma} rays to the exact result obtained from the on-step linking transitions.
Date: December 31, 1996
Creator: Lauritsen, T.; Khoo, T.L. & Janssens, R.V.F. and others
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Gamma-ray burst spectra and time histories from 2 to 400 keV

Description: The Gamma-Ray burst detector on Ginga consisted of a proportional counter to observe the x-rays and a scintillation counter to observe the gamma-rays. Both instrument recorded the time histories in phase with each other and with 0.03125 s temporal resolution. The author compares the average of 21 gamma-ray bursts to determine the delay, in any, between the peak of the x-rays and the peak of the gamma-rays. The delay is less than or about equal to 30 msec. Thus, models must content with two aver… more
Date: July 1, 1998
Creator: Fenimore, E.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Spectral measurements of few-electron uranium ions produced and trapped in a high-energy electron beam ion trap

Description: Measurements of 2s{sub l/2}-2p{sub 3/2} electric dipole and 2p{sub 1/2}-2p{sub 3/2} magnetic dipole and electric quadrupole transitions in U{sup 82+} through U{sup 89+} have been made with a high-resolution crystal spectrometer that recorded the line radiation from stationary ions produced and trapped in a high-energy electron beam ion trap. From the measurements we infer {minus}39.21 {plus_minus} 0.23 eV for the QED contribution to the 2s{sub 1/2}-2p{sub 3/2} transition energy of lithiumlike U… more
Date: November 4, 1994
Creator: Beiersdorfer, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RADIOISOTOPE IDENTIFICATION OF SHIELDED AND MASKED SNM RDD MATERIALS

Description: Sonar and speech techniques have been investigated to improve functionality and enable handheld and other man-portable, mobile, and portal systems to positively detect and identify illicit nuclear materials, with minimal data and with minimal false positives and false negatives. RadSonar isotope detection and identification is an algorithm development project funded by NA-22 and employing the resources of Savannah River National Laboratory and three University Laboratories (JHU-APL, UT-ARL, and… more
Date: June 17, 2010
Creator: Salaymeh, S. & Jeffcoat, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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First measurement of the degree of fragmentation of the decay out cascade from the superdeformed yrast band in {sup 192}Hg

Description: The decay spectrum of the yrast superdeformed band in {sup 192}Hg comprises a quasicontinuum with discrete lines ranging from 1 to 3.2 MeV. The intensity fluctuations of this quasicontinuum give information on the degree of fragmentation of the decay cascades and on the effect of pairing correlations on the level density {rho}(U) in the normal deformed well (0 < U < U{sub SD}).
Date: December 1, 1996
Creator: Lopez-Martens, A.; Hannachi, F. & Schueck, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High sensitivity gamma spectrometry of air samples near SRS during 1985-1995

Description: High sensitivity gamma analysis of off-site air samples near the Savannah River Site (SRS) is achieved by collecting large volume air samples for analysis by ultra-low-level gamma spectrometry. A review of the 1985-1995 measurements has highlighted local and distant releases of man-made radionuclides, along with cosmogenic radionuclides which correlate with both solar and seasonal phenomena. Measurements typically involve 2-day air collection of a 70,000 m{sup 3} sample on a 51 cm x 51 cm cellu… more
Date: July 1, 1997
Creator: Winn, W.G. & Cadieux, J.R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Simultaneous neutron and gamma spectrum adjustment

Description: The spectrum adjustment procedure was extended to simultaneous neutron and gamma spectrum adjustment, and the feasibility of this technique is demonstrated in the analysis of HFIR dosimetry experiments. Conditions in which gamma rays may contribute considerably to radiation damage in steels are discussed. Beryllium helium accumulation fluence monitors (HAFMs) were found to be good monitors in gamma fields of intensities high enough to contribute to steel embrittlement. Use of {sup 237}Np, {sup … more
Date: October 1, 1996
Creator: Remec, I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Approximate Public Key Authentication with Information Hiding

Description: This paper describes a solution for the problem of authenticating the shapes of statistically variant gamma spectra while simultaneously concealing the shapes and magnitudes of the sensitive spectra. The shape of a spectrum is given by the relative magnitudes and positions of the individual spectral elements. Class-specific linear orthonormal transformations of the measured spectra are used to produce output that meet both the authentication and concealment requirements. For purposes of conceal… more
Date: October 1, 2000
Creator: Thomas, Edward V. & Draelos, Timothy J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Chemical identity of atoms using core electron annihilations

Description: Positron annihilation spectroscopy is a sensitive probe for studying the electronic structure of defects in solids. The high momentum part of the Doppler-broadened annihilation spectra can be used to distinguish different elements. This is achieved by using a new two-detector coincidence system and by imposing appropriate kinematic cuts to exclude background events. The new setup improves the peak to background ratio in the annihilation spectrum to {approximately}10{sup 5}. As a result, the lin… more
Date: June 27, 1997
Creator: Asoka-Kumar, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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