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Neutron Nonelastic Cross-Section Measurements from 7 to 29 Mev

Description: Abstract: "Neutron nonelastic cross sections have been measured for 23 elements at 14 Mev, and for a selected set of these elements over the energy ranges 7 to 14 Mev and 21 to 29 Mev. Conventional sphere transmission techniques were used for the measurements. A comparison with optical model calculations of Bjorklund and Fernbach shows excellent agreement."
Date: May 19, 1958
Creator: MacGregor, Malcolm H.
Partner: UNT Libraries Government Documents Department

Triple Differential Cross sections and Nuclear Recoil in Two-Photon Double Ionization of Helium

Description: Triple differential cross sections (TDCS) for two-photon double ionization of helium are calculated using the method of exterior complex scaling both above and below the threshold for sequential ionization (54.4 eV). It is found that sequential ionization produces characteristic behavior in the TDCS that identifies that process when it is in competition with nonsequential ionization. Moreover we see the signature in the TDCS and nuclear recoil cross sections of"virtual sequential ionization" below the threshold for the sequential process.
Date: April 29, 2008
Creator: Horner, Daniel A.; McCurdy, C. William & Rescigno, Thomas N
Partner: UNT Libraries Government Documents Department

L- and M-Shell X-Ray Production Cross Sections of Neodymium Gadolinium, Holmium, Ytterbium, Gold and Lead by 25-MeV Carbon and 32-MeV Oxygen Ions

Description: L- and M-shell x-ray production cross sections have been measured for thin solid targets of neodymium, gadolinium, holmium, ytterbium, gold, and lead by 25 MeV 12/6C^q+ (q=4,5,6) and by 32 MeV 16/8O^q+ (q=5,7,8). The cross sections were determined from measurements made with thin targets (< 2.5 μg/cm2). For projectiles with one or two K-shell vacancies, the target x-ray production cross sections were found to be enhanced over those for projectiles without a K-shell vacancy. The sum of direct ionization to the continuum (DI) plus electron capture (EC) to the L, M, N... shells and EC to the K-shell of the projectile have been extracted from the data. The results are compared to the predictions of first Born theories, i.e., plane wave Born approximation for DI and Oppenheimer-Brinkman-Kramers formula of Nikolaev for EC and to the ECPSSR approach that accounts for Energy loss and Coulomb deflection of the projectile as well as for Relativistic and Perturbed Stationary States of inner shell electrons.
Date: August 1987
Creator: Andrews, Mike C., 1949-
Partner: UNT Libraries

Pre-Processing of Cross-Sections Using Dimensionality Reduction Techniques

Description: Reactor physics codes rely on cross-section data to determine, for example, flux profiles or burn-up calculations. This data contains cross section values for different neutron-atom interactions (e.g., absorption, fission and scattering) for a large number of isotopes as function of energy and it is tabulated for a specific set of parameters (e.g., moderator temperature, fuel temperature, moderator density). In order to perform such neutronic calculations, the amount of this data that needs to be stored is very large due to the high number of isotopes and many tabulation points are needed. This data needs to be retrieved at each time iteration of the code from the machine memory which negatively affects the computational time of the code itself.
Date: November 1, 2012
Creator: Mandelli, D.; Rabiti, C. & Alfonsi, A.
Partner: UNT Libraries Government Documents Department

Thermal-neutron capture for A=26-35

Description: The prompt gamma-ray data of thermal- neutron captures fornuclear mass number A=26-35 had been evaluated and published in "ATOMICDATA AND NUCLEAR DATA TABLES, 26, 511 (1981)". Since that time themanyexperimental data of the thermal-neutron captures have been measuredand published. The update of the evaluated prompt gamma-ray data is verynecessary for use in PGAA of high-resolution analytical prompt gamma-rayspectroscopy. Besides, the evaluation is also very needed in theEvaluated Nuclear Structure Data File, ENSDF, because there are no promptgamma-ray data in ENSDF. The levels, prompt gamma-rays and decay schemesof thermal-neutron captures for nuclides (26Mg, 27Al, 28Si, 29Si, 30Si,31P, 32S, 33S, 34S, and 35Cl) with nuclear mass number A=26-35 have beenevaluated on the basis of all experimental data. The normalizationfactors, from which absolute prompt gamma-ray intensity can be obtained,and necessary comments are given in the text. The ENSDF format has beenadopted in this evaluation. The physical check (intensity balance andenergy balance) of evaluated thermal-neutron capture data has been done.The evaluated data have been put into Evaluated Nuclear Structure DataFile, ENSDF. This evaluation may be considered as an update of the promptgamma-ray from thermal-neutron capture data tables as published in"ATOMIC DATA AND NUCLEAR DATA TABLES, 26, 511 (1981)".
Date: June 1, 2001
Creator: Chunmei, Z. & Firestone, R.B.
Partner: UNT Libraries Government Documents Department

Nuclear Recoil Cross Sections from Time-dependent Studies of Two-Photon Double Ionization of Helium

Description: We examine the sensitivity of nuclear recoil cross sections produced by two-photon double ionization of helium to the underlying triple differential cross sections (TDCS) used in their computation. We show that this sensitivity is greatest in the energy region just below the threshold for sequential double ionization. Accurate TDCS, extracted from non-perturbative solutions of the time-dependent Schroedinger equation, are used here in new computations of the nuclear recoil cross section.
Date: December 21, 2009
Creator: Horner, Daniel A.; Rescigno, Thomas N. & McCurdy, C. William
Partner: UNT Libraries Government Documents Department

Initial Estimate of the 237U(n,f) Cross Section for 0.1 (less than) En (MeV) (less than or equal to) 20

Description: In response to a request for a {sup 237}U(n,f) cross section evaluation up to E{sub n} = 20 MeV, they have married a data set from the previous reliable estimate [1-3] of the cross section up to E{sub n} = 2.5 MeV, to an estimate of the remaining cross section up to E{sub n} = 20 MeV, deduced from simple physics arguments. This straw-man, work-in-progress estimate of the {sup 237}U(n,f) cross section is intended to be used in sensitivity-test comparisons to other evaluations of the cross section (e.g., ENDF/B-VI [4] and ENDL [5]). The simple approach used in this work to generate a consistent cross section up to E{sub n} = 20 MeV is validated using the well-known {sup 235}U(n,f) cross section as a test case (see Fig. 1). The corresponding estimate of the {sup 237}U(n,f) cross section is plotted in Fig. 2 and listed in Table I.
Date: June 27, 2003
Creator: Younes, W; Britt, H C; Becker, J A & Wilhelmy, J B
Partner: UNT Libraries Government Documents Department

Summary Report: First Research Coordination Meeting on ReferenceDatabase for Neutron Activation Analysis

Description: Potential problems associated with nuclear data for neutronactivation analysis were identified, the scope of the work to beundertaken was defined together with its priorities, and tasks wereassigned to participants. Data testing and measurements refer to gammaspectrum peak evaluations, detector efficiency calibration, neutronspectrum characteristics and reference materials analysis.
Date: October 31, 2005
Creator: Firestone, Richard B. & Trkov, Andrej
Partner: UNT Libraries Government Documents Department

Status of experimental data base development relevant to spaceradiation transport and protection

Description: This report describes the highlights and progress made in aprogram of measurements studying radiation transport through materials ofinterest to NASA. All measurements were preformed at acceleratorfacilities, primarily using GCR-like heavy-ion beams incident uponvarious elemental and composite targets. Both primary and secondaryparticles exiting the target were measured. The secondary particlesinclude both charged particles and neutrons. These measurements serve asuseful benchmarks and input to transport model calculations.
Date: April 1, 2004
Creator: Heilbronn, Lawrence H.; Guetersloh, Stephen; Zeitlin, Cary & Miller, Jack
Partner: UNT Libraries Government Documents Department

K-Shell Ionization Cross Sections of Selected Elements from Ag to La for Proton Bombardment from 0.6 to 2.0 MeV

Description: The K-shell x-ray and ionization cross sections are measured for protons on Ag, Cd, Sn, Sb, Te, Ba, and La over the ion energy range of 0.6 to 2.0 MeV. The data are compared to the predictions of the PWBA, the PWBA with corrections for binding energy and/or Coulomb deflection, the BEA, and the constrained BEA predictions. In general, the non-relativistic PWBA with binding energy correction gives the best overall agreement with the measurements of proton-induced x-ray processes for the K-shell of the elements studied in this work. The data further suggest the need for relativistic PWBA treatment of the interactions in the K-shell for the range of binding energies represented by the elements investigated in this work.
Date: May 1974
Creator: Khelil, Najat Arafat
Partner: UNT Libraries

K-Shell Ionization Cross Sections For Elements Se To Pd: 0.4 To 2.0 MeV

Description: K-Shell ionization cross section for protons over the energy range of 0.4 to 2.0 MeV have been measured on thin targets of the elements Se, Br, Rb, Sr, Y, Mo and Pd. Total x-ray and ionization cross sections for the K-shell are reported. The experimental values of the ionization cross sections are compared to the non-relativistic plane-wave Born approximation, the binary-encounter approximation, the constrained binary-encounter approximation, and the plane-wave Born approximation with corrections for Coulomb-deflection and binding energy effects.
Date: December 1974
Creator: Criswell, Tommy L.
Partner: UNT Libraries

Measurement of gamma-ray total absorption cross sections using a [sup 56]Co source

Description: We have used a 150 MBq [sup 56]Co source to perform gamma-ray total absorption cross section measurements with very high precision. The use of [sup 56]Co allowed us to simultaneously measure the total cross section at 15 energies ranging from 0.847 MeV to 3.451 MeV. Seven sample materials were measured: Be, C, Cu, Ta, W, Pb, and U. In general, the measurement precision is better than 0.5% and in all cases better than 1.3%.
Date: December 1, 2008
Creator: Frankle, Christen M. & Moss, Calvin E.
Partner: UNT Libraries Government Documents Department

Two-photon double ionization of H2 at 30 eV using Exterior Complex Scaling

Description: Calculations of fully differential cross sections for two-photon double ionization of the hydrogen molecule with photons of 30 eV are reported. The results have been obtained by using the method of exterior complex scaling, which allows one to construct essentially exact wave functions that describe thedouble continuum on a large, but finite, volume. The calculated cross sections are compared with those previously obtained by Colgan et al., and discrepancies are found for specific molecular orientations and electron ejection directions.
Date: January 20, 2009
Creator: Morales, Felipe; Martin, Fernando; Horner, Daniel; Rescigno, Thomas N. & McCurdy, C. William
Partner: UNT Libraries Government Documents Department

Inelastic-Collision Cross Sections for Ne

Description: Cross sections for inelastic collisions of slow electrons and the dipole oscillator-strength distribution for the neon atom are given in tabular form. The results are based on experimental data that were checked and adjusted for internal consistency.
Date: 1976
Creator: Soong, S. C. & Kim, Yong-Ki
Partner: UNT Libraries Government Documents Department

Longitudinal double-spin asymmetry and cross section for inclusivejet production in polarized proton collisions at sqrt(s) = 200 GeV

Description: We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5<pT<50GeV/c and agree with next-to-leading order perturbative QCD evaluations.The A_LL data cover 5<pT<17 GeV/c and disfavor at 98 percentC.L. maximal positive gluon polarization in the polarizednucleon.
Date: August 10, 2006
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Partner: UNT Libraries Government Documents Department

CHARGE TRANSFER BETWEEN POSITIVE ALKALI IONS AND ATOMS

Description: The total cross sections for resonant charge exchange have been measured as a function of energy in the range from 10 to 500 eV for the Cs{sup +}-Cs, Rb{sup +}-Rb, and K{sup +}-K systems. The agreement with certain data obtained at higher energies for these systems, and with theoretical cross sections of Smirnov is satisfactory.
Date: April 1, 1968
Creator: Gentry, W.R.; Lee, Yuan-tseh & Mahan, Bruce H.
Partner: UNT Libraries Government Documents Department

The energy dependence of the total charm cross section

Description: We discuss the energy dependence of the total charm cross section and some of its theoretical uncertainties including the quark mass, scale choice and the parton densities. We compare the next-to-leading order calculation of the total cross section with results obtained using PYTHIA.
Date: October 18, 2007
Creator: Vogt, R
Partner: UNT Libraries Government Documents Department

Proceedings of the NEANDC/NEACRP Specialists Meeting on Fast Neutron Fission Cross Sections of U-233, U-235, U-238, and Pu-239, June 28-30, 1976, at Argonne National Laboratory

Description: Compilation of papers presented during the meeting of NEANDC/NEACRP specialists to discuss fast neutron fission cross sections of U-233, U-235, U-238, and Pu-239.
Date: 1976?
Creator: Poenitz, W. P. & Smith, A. B.
Partner: UNT Libraries Government Documents Department

Bottom Production from Fixed-Target to Large Hadron Collider Energies

Description: We present a state-of-the-art compilation of the existing bottom production cross sections in elementary collisions, from fixed-target to collider experiments. We then discuss the theoretical uncertainties on the total and differential bottom cross sections in the FONLL approach. In particular, we show total cross sections and kinematical distributions of the bottom hadrons and their decays: B {yields} e/{mu}X, B {yields} D {yields} e/{mu}, and B {yields} J/{psi}X. After seeing that the calculations give a good description of the existing measurements, we present detailed predictions for the LHC experiments in their specific phase space windows. Recent improvements in heavy quark production theory and experimental measurements at colliders, especially for bottom production, have shown that the perturbative QCD framework seems to work rather well, see Refs. [1, 2]. It is important to continue to validate this theoretical framework and its phenomenological inputs, extracted from other measurements, with new data such as that obtained by the CMS collaboration in pp collisions at {radical}s = 7 TeV. We validate the FONLL approach with lower energy data and also compare the results with preliminary LHC data. By showing good agreement between the calculations and the data, we demonstrate we can confidently extrapolate our results to energies appropriate for heavy-ion measurements. Total cross section calculations using the FONLL approach for pp {yields} B{bar B} show excellent agreement across a wide range of {radical}s at both full phase space and CDF phase space. This provides confidence that extrapolating to LHC energies will also show good agreement. Differential cross section FONLL calculations (d{sigma}/dp{sub T} and d{sigma}/d{eta}) at 7 TeV have been compared to preliminary CMS results. The agreement is quite striking. In addition, B fraction calculations have been made that also compare well to the CMS data. This should allow us to expect good agreement between further FONLL …
Date: November 30, 2010
Creator: Nelson, R. E.; Vogt, R.; Lourenco, C. & Wohri, H. K.
Partner: UNT Libraries Government Documents Department

Measurement of \nu_\mu and \bar\nu_\mu Induced Neutral Current Single $\pi^0$ Production Cross Sections on Mineral Oil at E_\nu~O(1 GeV)

Description: MiniBooNE reports the first absolute cross sections for neutral current single {pi}{sup 0} production on CH{sub 2} induced by neutrino and antineutrino interactions measured from the largest sets of NC {pi}{sup 0} events collected to date. The principal result consists of differential cross sections measured as functions of {pi}{sup 0} momentum and {pi}{sup 0} angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76 {+-} 0.05{sub stat} {+-} 0.40{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of &lt;E{sub {nu}}&gt; = 808 MeV and (1.48 {+-} 0.05{sub stat} {+-} 0.14{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of &lt;E{sub {nu}}&gt; = 664 MeV for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} induced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1{pi}{sup 0} production corrected for the effects of final state interactions to compare to prior results.
Date: November 1, 2009
Creator: Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L. et al.
Partner: UNT Libraries Government Documents Department
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