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Euclidean responses of 4He at high momentum transfer

Description: The Euclidean proton and nucleon responses of <sup>4</sup>He at <I>q</I>=10 fm<sup>-1</sup>, evaluated with the correlated Glauber approximation using a realistic nucleon-nucleon interaction and nonrelativistic kinematics, are compared to those obtained from the Green's function Monte Carlo approach. The results show that final state interactions play a crucial role even at this large value of q, and that their effect can be quantitatively accounted for with the correlated Glauber approximation.
Date: July 1, 1995
Creator: Carlson, Joseph; Benhar, Omar; Schiavilla, Rocco & Pandharipande, Vijay
Partner: UNT Libraries Government Documents Department

Soft Contribution to Form Factors of Gamma<sup>*</sup> p -> Delta<sup>+</sup> Transition

Description: The purely nonperturbative soft contribution to the gamma<sup>*</sup> p -> delta<sup>+</sup> transition form factors is estimated using the local quark-hadron duality approach. Our results show that the soft contribution is dominated by the magnetic transition: the ratio G<sup>*</sup> <sub>E</sub> Q<sup>2</sup>/ G<sup>*</sup><sub>M</sub> Q<sup>2</sup> is small for all accessible Q<sup>2</sup>, in contrast to pQCD expectations that G<sup>*</sup><sub>E</sub> (Q<sup>2</sup>) -> -G<sup>*</sup><sub>M</sub> (Q<sup>2</sup>). We also found that the soft contribution to the magnetic form factor is large enough to explain the magnitude of existing experimental data.
Date: September 1, 1995
Creator: Radyushkin, Anatoly & Belyaev, Vladimir
Partner: UNT Libraries Government Documents Department

The Inclusive Muon Neutrino Reaction In 12C

Description: We calculate the charged current inclusive cross section for the reaction, v(sub)u +12C ->u^- + X, from the threshold to 300 MeV.In addition we obtain the average cross section over the spectrum currently being produced at LAMPF.We discuss our results with respect to the current experimental work and consider the possible contributions from higher l states.
Date: November 1, 1995
Creator: Pourkaviani, M. & Mintz, S.
Partner: UNT Libraries Government Documents Department

A Comment on General Formulae for Polarization Observables in Deuteron Electrodisintegration and Linear Relations

Description: We establish a simple, explicit relation between the formalisms employed in the treatments of polarization observables in deuteron two-body electrodisintegration published by Arenhovel, Leidemann, and Tomusiak in Few-Body Systems 15 , 109 (1993) and the results of the present authors published in Phys. Rev. C 40, 2479 (1989). We comment on the overlap between the two sets of results.
Date: July 1, 1995
Creator: Gross, Franz & Dmitrasinovic, Veljko
Partner: UNT Libraries Government Documents Department

Quark-Hadron Duality and Intrinsic Transverse Momentum

Description: It is demonstrated in several exclusive processes involving the pion that a local quark-hadron duality prescription is equivalent to using an effective (bar)qq (two-body) light-cone wave function Psi (sup) (LD) (x, k (sub)perpendicular) for the pion. This wave function models soft dynamics of all higher (bar)qG...Gq Fock components of the standard light-cone approach. Contributions corresponding to higher Fock components in a hard regime appear in this approach as radiative corrections and are suppressed by powers of alpha(sub)s / Pi.
Date: November 1, 1995
Creator: Radyushkin, Anatoly
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Upgrade Piping Loads on Cleanroom Roof

Description: The proposed piping layout for the DO upgrade will run along the south wall of DAB. The cryogenic service pipe runs above the upper and lower cleanroom roofs and will need to be supported by the roofs beams. Calculations were done to determine the stresses in the I-beams created by the existing and additional loads due to the upgrade. Refer to drawing no. 3823.115-ME-317283 for drawings of the piping layout. Figure 1 shows the 'plan view' portion of this drawing. The weight of the individual lines were calculated in figure 2 assuming a pipe density of O.28 lbm/in{sup 3} for stainless steel (0.12% C) and a fluid density (assuming LN2 at 1 atm) of 0.03 lbm/in{sup 3}. The weights of the corrugated steel flooring, assembly hall feed cans, support beams, and roof hatch were also included in the analysis. These loads are calculated on pgs. 5-6. A floor load of 50 lbf/ft{sup 2} was also added in order to maintain the existing floor load limit in addition to the added piping loads. Measurements of the dimensions of the I-beams determined that the nominal sizes of the beams were W8 x 21 for the lower roof and W14 x 26 for the upper roof. Pipe lengths were determined from the drawing for each of the lines on pgs. 1-2 of the calculations (refer to all piping by line numbers according to figure 2). A total weight was calculated for lines 3-9 along the south wall and lines 1-2 running along the north wall of the lower cleanroom roof. To simplify the calculations these weights were assumed to be evenly distributed on the 5 I-beam supports of the lower cleanroom roof 2.5 feet in from the south wall. The stress analysis was done using FrameMac, a 2-D finite element program for the ...
Date: August 28, 1995
Creator: Sakla, Steve
Partner: UNT Libraries Government Documents Department

The production of {pi}{sup {+-}}, K{sup {+-}}, p, k{sup 0} and {Lambda}{sup 0} in hadronic Z{sup 0} decays

Description: The authors have measured production fractions and spectra for {pi}{sup {+-}}, K{sup {+-}} and p, and production spectra for K{sup 0} and {Lambda}{sup 0} in both hadronic Z{sup 0} decays and a Z{sup 0} {yields} light quark (uds) subset at SLD. The SLD Cherenkov Ring Imaging Detector was used to identify charged hadrons. The CCD vertex detector was used to select the enriched uds sample. For the global sample, the results are consistent with previous experiments. The authors observe a clear flavor dependence in production spectra, but only a small effect in hadron fractions and {xi} = ln(1/x{sub p}) peak positions.
Date: August 1, 1995
Creator: Baird, K.
Partner: UNT Libraries Government Documents Department

Measuring sticking and stripping in muon catalyzed dt fusion with multilayer thin films

Description: The authors propose a direct measurement of muon sticking to alpha particles in muon catalyzed dt fusion at a high density. Exploiting the features of a multilayer thin film target developed at TRIUMF, the sticking is determined directly by detection of charged fusion products. Experimental separation of initial ticking and stripping may become possible for the first time. Monte Carlo simulations, as well as preliminary results of test measurements are described.
Date: December 1, 1995
Creator: Fujiwara, M.C.; Bailey, J.M. & Beer, G.A.
Partner: UNT Libraries Government Documents Department

Ion cyclotron emission due to the newly-born fusion products induced fast Alfven wave radiative instabilities in tokamaks

Description: The velocity distribution functions of the newly born (t = 0) charged fusion products of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v{sub {parallel}} such that v{sub {perpendicular}} {approx} v{sub {parallel}} {approx} v{sub j} where (M{sub j}V{sub j}{sup 2}/2) = E{sub j}, the directed birth energy of the charged fusion product species j of mass M{sub j}. As the time t progresses these distribution functions will evolve into a Gaussian in velocity with thermal spreadings given by the perpendicular and parallel temperatures T{sub {perpendicular}j}(t) = T{sub {parallel}j}(t) with T{sub j}(t) increasing as t increases and finally reaches an isotropic saturation value of T{sub {perpendicular}j}(t {approx} {tau}{sub j}) = T{sub {parallel}j}(t {approx} {tau}{sub j}) = T{sub j}(t {approx} {tau}{sub j}) {approx} [M{sub j}T{sub d}E{sub j}/(M{sub j} + M)]{sup 1/2}, where T{sub d} is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j = protons and alpha particles, respectively, and {tau}{sub j} {approx} {tau}{sub sj}/4 is the thermalization time of the fusion product species j in the background deuterium plasma and {tau}{sub sj} is the slowing-down time. For times t of the order of {tau}{sub j} their distributions can be approximated by a Gaussian in their total energy. Then for times t {ge} {tau}{sub sj} the velocity distributions of these fusion products will relax towards their appropriate slowing-down distributions. Here the authors will examine the radiative stability of all these distributions. The ion cyclotron emission from energetic ion produced by fusion reactions or neutral beam injection promises to be a useful diagnostic tool.
Date: August 1, 1995
Creator: Arunasalam, V.
Partner: UNT Libraries Government Documents Department

TAE modes and MHD activity in TFTR DT plasmas

Description: The high power deuterium and tritium experiments on TFTR have produced fusion a parameters similar to those expected on ITER. The achieved {beta}{sub {alpha}}/{beta} and the R{triangledown}{beta}{sub {alpha}} in TFRR D-T shots are 1/2 to 1/3 those predicted in the ITER EDA. Studies of the initial TFTR D-T plasmas find no evidence that the presence of the fast fusion {alpha} population has affected the stability of MHD, with the possible exception of Toroidal Alfven Eigenmodes (TAE`s). The initial TFTR DT plasmas had MHD activity similar to that commonly seen in deuterium plasmas. Operation of TFTR at plasma currents of 2.0--2.5 MA has greatly reduced the deleterious effects of MHD commonly observed at lower currents. Even at these higher currents, the performance of TFTR is limited by {beta}-limit disruptions. The effects of MHD on D-T fusion {alpha}`s was similar to effects observed on other fusion products in D only plasmas.
Date: March 1, 1995
Creator: Fredrickson, E.; Batha, S. & Bell, M.
Partner: UNT Libraries Government Documents Department

Decontamination of surfaces by blasting with crystals of H{sub 2}O and CO{sub 2}

Description: A major mission of the US Department of Energy during the 1990s is site and environmental cleanup. In pursuit of this mission, numerous remediation projects are under way and many others are being planned at Oak Ridge National Laboratory (ORNL). In this report, tests using two proposed methods for decontaminating surfaces one using water ice crystals [Crystalline Ice Blast (CIB)], the other using dry ice crystals (CO{sub 2} Cleanblast{trademark}) -- are described. Both methods are adaptations of the commonly used sand blasting technology. The two methods tested differ from sand blasting in that the particles are not particularly abrasive and do not accumulate as particles in the wastes. They differ from each other in that the CO{sub 2} particles sublime during and after impact and the ice particles melt. Thus, the two demonstrations provide important information about two strong candidate decontamination methodologies. Each process was tested at ORNL using contaminated lead bricks and contaminated tools and equipment. Demonstrations with the prototype Crystalline Ice Blast and the CO{sub 2} Cleanblast systems showed that paint, grease, and oil can be removed from metal, plastic, asphalt, and concrete surfaces. Furthermore, removal of contamination from lead bricks was highly effective. Both processes were found to be less effective, under the conditions tested, with contaminated tools and equipment that had chemically bonded contamination or contamination located in crevices since neither technology abrades the substrates or penetrates deeply into crevices to remove particulates. Some process improvements are recommended.
Date: February 1, 1995
Creator: Benson, C.E.; Parfitt, J.E. & Patton, B.D.
Partner: UNT Libraries Government Documents Department

Electro symmetry breaking and beyond the standard model

Description: The development of the Standard Model of particle physics is a remarkable success story. Its many facets have been tested at present day accelerators; no significant unambiguous deviations have yet been found. In some cases, the model has been verified at an accuracy of better than one part in a thousand. This state of affairs presents our field with a challenge. Where do we go from here? What is our vision for future developments in particle physics? Are particle physicists` recent successes a signal of the field`s impending demise, or do real long-term prospects exist for further progress? We assert that the long-term health and intellectual vitality of particle physics depends crucially on the development of a new generation of particle colliders that push the energy frontier by an order of magnitude beyond present capabilities. In this report, we address the scientific issues underlying this assertion.
Date: May 1, 1995
Creator: Barklow, T.; Dawson, S.; Haber, H.E. & Siegrist, J.
Partner: UNT Libraries Government Documents Department

Observation of the top quark

Description: The DO collaboration reports on a search for the Standard Model top quark in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50 pb{sup {minus}1}. We have searched for t{bar t} production in the dilepton and single-lepton decay channels, with and without tagging of b quark jets. We observe 17 events with an expected background of 3.8 {plus_minus} 0.6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2 {times} 10{sup {minus}6} (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199{sub {minus}21}{sup +19} (stat.) {plus_minus}22 (syst.) GeV/c{sup 2} and its production cross section to be 6.4 {plus_minus} 2.2 pb.
Date: May 1, 1995
Creator: Greenlee, H.
Partner: UNT Libraries Government Documents Department

High energy physics research. Final report, October 1, 1969--December 31, 1990

Description: The goal of this research was to understand the fundamental constituents of matter and their interactions. First, a brief history of the high energy research at Princeton University is presented. Next, the extensive research covered in this 21 year period is summarized. Finally, a list of all publications issued during this period is presented.
Date: May 1995
Partner: UNT Libraries Government Documents Department

First evidence of collective alpha particle effect on TAE modes in the TFTR D-T experiment

Description: The alpha particle effect on the excitation of toroidal Alfven eigenmodes (TAE) was investigated in deuterium-tritium (d-t) plasmas in the Tokamak Fusion Test Reactor (TFTR). RF power was used to position the plasma near the instability threshold, and the alpha particle effect was inferred from the reduction of RF power threshold for TAE instability in d-t plasmas. Initial calculations indicate that the alpha particles contribute 10--30% of the total drive in a d-t plasma with 3 MW of peak fusion power.
Date: August 1, 1995
Creator: Wong, K.L.; Schmidt, G. & Batha, S.H.
Partner: UNT Libraries Government Documents Department

Postirradiation evaluations of capsules HANS-1 and HANS-2 irradiated in the HFIR target region in support of fuel development for the advanced neutron source

Description: This report describes the design, fabrication, irradiation, and evaluation of two capsule tests containing U{sub 3}Si{sub 2} fuel particles in contact with aluminum. The tests were in support of fuel qualification for the Advanced Neutron Source (ANS) reactor, a high-powered research reactor that was planned for the Oak Ridge National Laboratory. At the time of these tests, the fuel consisted of U{sub 3}Si{sub 2}, containing highly enriched uranium dispersed in aluminum at a volume fraction of {approximately}0.15. The extremely high thermal flux in the target region of the High Flux Isotope Reactor provided up to 90% burnup in one 23-d cycle. Temperatures up to 450{degrees}C were maintained by gamma heating. Passive SiC temperature monitors were employed. The very small specimen size allowed only microstructural examination of the fuel particles but also allowed many specimens to be tested at a range of temperatures. The determination of fission gas bubble morphology by microstructural examination has been beneficial in developing a fuel performance model that allows prediction of fuel performance under these extreme conditions. The results indicate that performance of the reference fuel would be satisfactory under the ANS conditions. In addition to U{sub 3}Si{sub 2}, particles of U{sub 3}Si, UAl{sub 2}, UAl{sub x}, and U{sub 3}O{sub 8} were tested.
Date: August 1, 1995
Creator: Hofman, G.L.; Snelgrove, J.L. & Copeland, G.L.
Partner: UNT Libraries Government Documents Department

An update on (n,charged particle) research at WNR

Description: Neutron-induced reactions producing light charged particles continue to be investigated at the spallation fast-neutron source at the Los Alamos Neutron Science Center (LANSCE). New data on the cross sections for alpha-particle production for neutrons on {sup 58}Ni and {sup 60}Ni are presented from threshold to 50 MeV. Recent changes in the experiment now allow protons, deuterons, tritons, {sup 3}He and alpha particles to be identified.
Date: December 31, 1995
Creator: Haight, R.C.; Bateman, F.B.; Sterbenz, S.M.; Grimes, S.M.; Wasson, O.A.; Maier-Komor, P. et al.
Partner: UNT Libraries Government Documents Department

Search for {Sigma}{sub c} {yields} {Lambda}{sub c}{pi} using {Lambda}{sub c} {yields} {Sigma}{sub s}{pi}{pi} in 250 GeV {pi}{sup {minus}}-nucleon interactions

Description: Combined cross section times branching fraction limits are given for {Sigma}{sub c}{sup +}{sup +} {r_arrow} {Lambda}{sub c}{sup +}{pi}{sup +} and {Sigma}{sub c}{sup 0} {r_arrow} {Lambda}{sub c}{sup +}{pi}{sup {minus}} where {Lambda}{sub c}{sup +} {r_arrow} {Sigma}{sub s}{sup {plus_minus}}{pi}{sup {plus_minus}}{pi}{sup +}. The {Lambda}{sub c}{sup +} is reconstructed with partial information on the {Sigma}{sub s}; the missing {Sigma}{sub s} momentum is established through momentum conservation imposed by a constrained fit. The data are of {pi}{sup {minus}} beam interactions at 250 GeV from Fermilab experiment E769.
Date: October 10, 1995
Creator: Passmore, D.A.
Partner: UNT Libraries Government Documents Department

3D Fokker-Planck modeling of axisymmetric collisional losses of fusion products in TFTR

Description: Results of a 3D (in constants of motion space) Fokker-Planck simulation of collisional losses of fusion products in axisymmetric DT and DD discharges on TFTR are presented. The distributions of escaped ions over poloidal angle, pitch angle, and their energy spectra are obtained. Axisymmetric collisional losses of fusion products are found to be less than (2--5)%. The distribution of confined fusion products is shown to be strongly anisotropic and nonuniform in the radial coordinate mainly for slowed-down fusion products with small longitudinal energy. Comparison of these results of modeling and experimental data is done.
Date: October 1995
Creator: Goloborod`ko, V. Ya.; Reznik, S. N.; Yavorskij, V. A. & Zweben, S. J.
Partner: UNT Libraries Government Documents Department

Alpha-physics and measurement requirements for ITER

Description: This paper reviews alpha particle physics issues in ITER and their implications for alpha particle measurements. A comparison is made between alpha heating in ITER and NBI and ICRH heating systems in present tokamaks, and alpha particle issues in ITER are discussed in three physics areas: `single particle` alpha effects, `collective` alpha effects, and RF interactions with alpha particles. 29 refs., 4 figs., 4 tabs.
Date: December 31, 1995
Creator: Zweben, S.J.; Young, K.M.; Putvinski, S.; Petrov, M.P.; Sadler, G. & Tobita, K.
Partner: UNT Libraries Government Documents Department

Foil deposition alpha collector probe for TFTR`s D-T phase

Description: A new foil deposition alpha collector sample probe has been developed for TFTR`s D-T phase. D-T fusion produced alpha particles escaping from the plasma are implanted in nickel foils located in a series of collimating ports on the detector. The nickel foils are removed from the tokamak after exposure to one or more plasma discharges and analyzed for helium content. This detector is intended to provide improved alpha particle energy resolution and pitch angle coverage over existing lost alpha detectors, and to provide an absolutely calibrated cross-check with these detectors. The ability to resolve between separate energy components of alpha particle loss is estimated to be {approx} 20%. A full 360{degree} of pitch angle coverage is provided for by 8 channels having an acceptance range of {approx} 53{degree} per channel. These detectors will be useful in characterizing classical and anomalous alpha losses and any collective alpha instabilities that may be excited during the D-T campaign of TFTR.
Date: March 1, 1995
Creator: Hermann, H.W.; Darrow, D.S.; Timberlake, J.; Zweben, S.J.; Chong, G.P.; Pitcher, C.S. et al.
Partner: UNT Libraries Government Documents Department

Measurement of loss of DT fusion products using scintillator detectors in TFTR

Description: A poloidal array of MeV ion loss probes previously used to measure DD fusion product loss has been upgraded to measure the loss of alpha particles from DT plasmas in TFTR. The following improvements to the system have been made in preparation for the use of tritium in TFTR: (1) relocation of detectors to a neutronshielded enclosure in the basement to reduce neutron-induced background signals; (2) replacement of ZnS:Cu (P31) scintillators in the probes with the Y{sub 3}Al{sub 5}0{sub 12}:Ce(P46) variety to minimize damage and assure linearity at the fluxes anticipated from DT plasmas; and (3) shielding of the fiber optic bundles which carry the fight from the probes to the detectors to reduce neutron- and gamma-induced light within them. In addition to the above preparations, the probes have been absolutely calibrated for alpha particles by using the Van de Graaf accelerator at Los Alamos National Laboratory. Alpha particle losses from DT plasmas have been observed, and losses at the detector 901 below the midplane are consistent with first orbit loss.
Date: March 1, 1995
Creator: Darrow, D.S.; Herrmann, H.W.; Johnson, D.W.; Marsala, R.J.; Palladino, R.W.; Zweben, S.J. et al.
Partner: UNT Libraries Government Documents Department