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in subjects: "Cross Sections"

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/sup 16/O + /sup 40/Ca inelastic scattering and the elastic scattering wave function

The /sup 16/O + /sup 40/Ca inelastic scattering has been measured at 60-MeV incident energy, and evidence has been found in support of an explicit coupling between direct and elastic channels. The measurements were extended over a large angular range and in particular to very forward angles. The ratio of cross sections between extreme forward and backward angles proved very useful in studying the underlying reaction mechanism.

Date: January 1, 1977

Creator: Rehm, K.E.; Henning, W.; Erskine, J.R. & Kovar, D.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Di-leptons at the Bevalac

Recent results on the production of di-leptons measured by the Di-Lepton-Spectrometer (DLS) collaboration are discussed. Results are reported from observations made on p /plus/ Be collisions with proton beams from 1.0 to 4.9 GeV and on Ca collisions with calcium beams of 1.0 to 2.0 GeV/A. The shape of the distributions are similar to that at higher energies. The low mass cross section appears to be explained by ..pi..-..pi.. annihilation, but detailed calculations are needed to substantiate tha… more

Date: March 1, 1988

Creator: Matis, H.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Structure functions: Their status and implications

I discuss the current status of structure functions. Attention is given to the uncertainties in them and the implications of these uncertainties for experimental predictions. I indicate which experiments are capable of removing these uncertainties. 17 refs., 17 figs., 1 tab.

Date: September 29, 1988

Creator: Hinchliffe, I.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A benchmark-problem specification and calculation using SENSIBL, a one- and two-dimensional sensitivity and uncertainty analysis code of the AARE system

The lack of suitable benchmark problems makes it difficult to test sensitivity codes with a covariance library. A benchmark problem has therefore been defined for one- and two-dimensional sensitivity and uncertainity analysis codes and code systems. The problem, representative of a fusion reactor blanket, has a simple, three-zone )tau)-z geometry containing a D-T fusion neutron source distributed in a central void region surrounded by a thick /sup 6/LiH annulus. The response of interest is the … more

Date: January 1, 1988

Creator: Muir, D. W.; Davidson, J. W.; Dudziak, D. J.; Davierwalla, D. M.; Higgs, C. E. & Stepanek, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fast-neutron total and scattering cross sections of elemental palladium

Neutron total cross sections of palladium are measured from approx. = 0.6 to 4.5 MeV with resolutions of approx. = 30 to 70 keV at intervals of less than or equal to 50 keV. Differential neutron elastic- and inelastic-scattering cross sections are measured from 1.4 to 3.85 MeV at intervals of 50 to 100 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160/sup 0/. The experimental results are compared with respective quantities given in ENDF/B-V and used to deduce an opt… more

Date: June 1, 1982

Creator: Smith, A. B.; Guenther, P. T. & Whalen, J. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Total hadron cross section, new particles, and muon electron events in e/sup +/e/sup -/ annihilation at SPEAR

The review of total hadron electroproduction cross sections, the new states, and the muon--electron events includes large amount of information on hadron structure, nine states with width ranging from 10's of keV to many MeV, the principal decay modes and quantum numbers of some of the states, and limits on charm particle production. 13 references. (JFP)

Date: January 1, 1976

Creator: Richter, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Physics of antimatter-matter reactions for interstellar propulsion

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) … more

Date: August 22, 1986

Creator: Morgan, D.L. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron scattering from solutions: the hydration of lanthanide and actinide ions

The neutron scattering difference method is described and applied to investigations of the aqua rare-earth ions, Nd/sup 3 +/ and Dy/sup 3 +/. Metal-water distances and hydration numbers have been unambiguously determined for these ions' inner coordination spheres. The values of the hydration number, n, of 8.5 +- 0.2 for Nd/sup 3 +/ and 7.4 +- 0.5 for Dy/sup 3 +/, directly support the claim of Spedding et al. that n decreases by one unit across the lanthanide series. The possible application of … more

Date: January 1, 1985

Creator: Hahn, R.L.; Narten, A.H. & Annis, B.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fractional processes and nuclear disassembly in very-heavy-ion collisions in the Fermi energy regime

Exclusive measurements of charged products and neutrons were performed for the reactions {sup 197}Au + (29 MeV/u) {sup 208}Pb and {sup 209}Bi + (28.2 MeV/u) {sup 136}Xe. The multiplicities of neutrons and charged particles are found to indicate collision impact parameters with different sensitivities. Characteristic correlations observed between massive products and light particles suggest the dominance of the damped-reaction mechanism in the Fermi energy domain. For central collisions, massive… more

Date: January 1, 1991

Creator: Schroeder, W.U.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cross Sections for X-Ray Photoelectron-Induced Desorption of Hydrogen Ions From Metal Surfaces

We have measured the cross sections for x-ray photoelectron-induced desorption of hydrogen ions from beryllium, carbon, aluminum, tantalum, and gold surfaces. This report describes the results of the cross-section measurements, and discusses a time-of-flight technique that allows the determination of ionic-desorption cross sections as small as 10/sup -25/ cm/sup 2/ per photoelectron. 19 refs., 7 figs.

Date: September 20, 1985

Creator: Kinney, J. H.; Siekhaus, W. J. & Anderson, R. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Sensitivity of primary knock-on atom spectra and displacement per atom cross sections to different secondary neutron energy and angular distributions and ''in-group'' weighting schemes

The sensitivity of primary knock-on atom (PKA) spectra and displacement per atom (DPA) cross sections to different secondary neutron energy and angular distributions and ''in-group'' weighting schemes is investigated. It is shown that the sensitivity of the PKA spectra and DPA cross sections for the (n,n' unresolved) and (n,2n) reactions in Fe to different angular distributions and the same secondary neutron spectrum is reasonably large (approximately 15%), whereas the … more

Date: January 1, 1978

Creator: Gabriel, T. A. & Bishop, B. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Mechanism of (n,. gamma. ) reaction at low neutron energies

We discuss the interplay between direct capture, valence capture, and compound-nuclear capture in attempting to explain the vast amount of capture data for light-mass nuclei. 13 refs.

Date: January 1, 1991

Creator: Raman, S. (Oak Ridge National Lab., TN (United States)) & Lynn, J.E. (Los Alamos National Lab., NM (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Collisionally excited few-electron systems: theoretical introduction and survey. [2-200 keV]

We consider excitation, ionization, and charge transfer in collisions of protons (and antiprotons) with the single-electron targets H, He/sup +/, and Li/sup 2 +/. These collisions are first compared to other types of ion-atom collisions. A brief review of our own theoretical method is given; in particular we describe how we allow for both large charge transfer and ionization probabilities while retaining the computational efficiency that allows us to consider a variety of collision partners and… more

Date: January 1, 1982

Creator: Ford, A.L.; Reading, J.F. & Becker, R.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Ab initio calculations on collisions of low energy electrons with polyatomic molecules

The Kohn variational method is one of simplest, and oldest, techniques for performing scattering calculations. Nevertheless, a number of formal problems, as well as practical difficulties associated with the computation of certain required matrix elements, delayed its application to electron--molecule scattering problems for many years. This paper will describe the recent theoretical and computational developments that have made the complex'' Kohn variational method a practical tool for carryin… more

Date: August 1, 1991

Creator: Rescigno, T. N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Particle production and spectra in E802 at BNL-AGS

The production of {pi}, K, and protons measured in the E802 spectrometer are studied for p+A and Si+A collisions. Systematic properties of particle spectra and rapidity density distributions are discussed in terms of centrality and reaction system. A detailed comparison of the data to the RQMD model, which employs the experimental acceptance and cuts are presented. 8 refs., 6 figs.

Date: January 1, 1991

Creator: Videbaek, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Some effects on the kinetics of muon-catalyzed fusion

Two important stages in the kinetics of muon-catalyzed d-t fusion are discussed: (1) atomic thermalization and hyperfine-state relaxation preceding molecular formation and (2) muon stripping and x-ray production if sticking occurs after nuclear fusion. Thermalization is accurately treated by Monte Carlo simulation. It is shown that thermalization and triplet quenching of the ..cap alpha mu.. atom may not finish before dt..mu.. formation in low-tritium targets, but that epithermal transients are… more

Date: January 1, 1986

Creator: Cohen, J.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Two-photon interactions from Mark II at SPEAR

Results on the two-photon production of the eta', f(1270), A/sub 2/(1310), and f'(1515) mesons at SPEAR energies are presented using data taken with the Mark II detector. The radiative width of the eta' has been determined to be GAMMA/sub ..gamma gamma../(eta') = 5.8 +- 1.1 keV (20% systematic uncertainty). Upper limits for the radiative widths of the f, A/sub 2/, and f' have been determined.

Date: May 1, 1980

Creator: Hollebeek, Robert

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Jet rates from deep inelastic muon scattering in the W range of 15 to 35 GeV

Production rates of forward jets in deep inelastic muon scattering are studied using the JADE jet finding algorithm. The evolution of di-jet rates with W is compared to QCD first order predictions in the W range of 15 to 25 GeV. 7 refs., 3 figs.

Date: August 1, 1991

Creator: Salgado, C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Vacuum considerations summary

The vacuum system for Heavy Ion Fusion machines can be divided according to pressure into 4 parts: (a) Ion Sources; (b) Linear Accelerators; (c) Circular Accelerators, Accumulators and Storage Rings; and (d) Reactors. Since ion sources will need rather conventional pumping arrangements and reactors will operate with greater pressures, depending on their mode of operation, only items b and c will be treated in this report. In particular, the vacuum system design will be suggested for the machine… more

Date: January 1, 1977

Item Type: Article

Partner: UNT Libraries Government Documents Department

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HIFI: a computer code for projectile fragmentation accompanied by incomplete fusion

A brief summary of a model proposed to describe projectile fragmentation accompanied by incomplete fusion and the instructions for the use of the computer code HIFI are given. The code HIFI calculates single inclusive spectra, coincident spectra and excitation functions resulting from particle-induced reactions. It is a multipurpose program which can calculate any type of coincident spectra as long as the reaction is assumed to take place in two steps.

Date: July 1, 1980

Creator: Wu, J.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Quarks and gluons in hadrons and nuclei

These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of th… more

Date: December 1, 1989

Creator: Close, F. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Cross sections for the /sup 7/Li(n,xn) and /sup 7/Li(n,n'. gamma. ) reactions between 1 and 20 MeV

Differential cross sections for the production of secondary neutrons and gamma rays from neutron interactions in /sup 7/Li have been measured at 50/sup 0/ and 126/sup 0/ (lab) for incident neutron energies in the range 1 to 20 MeV. An electron linac was used as a white neutron source. Incident neutron energies were determined using time-of-flight techniques for a source-to-sample distance of 48 m. Secondary spectra were determined by analysis of the pulse-height distributions observed in a NE-2… more

Date: March 1, 1978

Creator: Morgan, G. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Measuring the mass and width of the Z sup 0 : The status of the energy spectrometers

The Stanford Linear Collider (SLC) located at the Stanford Linear Accelerator Center (SLAC) collides electrons and positrons produced in the linear accelerator pulse by pulse. The object is to produce collisions energetic enough to produce the heavy intermediate vector boson, the Z{sup 0}. An essential component of the SLC physics program is the precise knowledge of the center-of-mass energy of each interaction. We measure the energy of each collision by using two energy spectrometers. The spec… more

Date: May 1, 1989

Creator: Rouse, F.; Levi, M. (Lawrence Berkeley Lab., CA (United States)); Kent, J.; King, M.; Von Zanthier, C.; Watson, S. (California Univ., Santa Cruz, CA (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

(Theoretical studies in elementary particle physics)

This report discusses research in: spin physics; transverse polarization and jet production; fundamental QCD; intermediate vector boson production; and hadron collisions. (LSP)

Date: January 1, 1991

Creator: Collins, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department