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Comparison of q anti qg and q anti q. gamma. events in e/sup +/e/sup -/ annihilation at PEP

Description: In comparing the particle flow in the event plane of three-jet (q anti qg) events and of radiative annihilation events (q anti q..gamma..) for similar kinematic configurations, two PEP experiments find a significant decrease in particle density in the angular region opposite to the gluon jet in q anti qg events, relative to the particle density in the region opposite to the photon in q anti q..gamma.. events. The effect is predicted both by QCD and by phenomenological string models. 5 refs., 5 figs.
Date: July 1, 1986
Creator: Hofmann, W.
Partner: UNT Libraries Government Documents Department

Physics of very high energy hadron-hadron colliders

Description: A review is given of the physics accessible at a very high energy hadron-hadron collider. Emphasis is placed on the reliability of the predicted rates, and upon the energy and luminosity required to explore new physics options. 38 refs., 19 figs.
Date: September 1, 1986
Creator: Hinchliffe, I.
Partner: UNT Libraries Government Documents Department

Specialty magnets

Description: A number of basic conceptual designs are explained for magnet systems that use permanent magnet materials. Included are iron free multipoles and hybrid magnets. Also appended is a discussion of the manufacturing process and magnetic properties of some permanent magnet materials. (LEW)
Date: July 1, 1986
Creator: Halbach, K.
Partner: UNT Libraries Government Documents Department

Harmonic superspace formalism and the consistent chiral anomaly

Description: The harmonic superspace formalism has been used to construct the consistent chiral anomaly in N = 1, d = 6 supersymmetric Yang-Mills thoery. The expressions of the gauge anomaly ..delta../sub s//sup phi/ and of the supersymmetric anomaly ..delta../sub SUSY//sup phi/ are given together with the consistent condition. 7 refs.
Date: August 1, 1986
Creator: Li, W.
Partner: UNT Libraries Government Documents Department

Effects of silica redistribution on performance of high-level nuclear waste repositories in saturated geologic formations

Description: Evaluation of the thermohydrological conditions near high-level waste packages is needed for the design of the waste canister and for overall repository design and performance assessment. Most available studies in this area have assumed that the hydrologic properties of the host rock do not change in response to the thermal, mechanical or chemical effects caused by waste emplacement. However, the ramifications of this simplifying assumption have not been substantiated. We have studied dissolution and precipitation of silica in thermally driven flow systems, including changes in formation porosity and permeability. Using numerical simulation, we compare predictions of thermohydrological conditions with and without inclusion of silica redistribution effects. Two cases were studied, namely, a canister-scale problem, a repository-wide thermal convection problem, and different pore models were employed for the permeable medium (fractures with uniform or non-uniform cross sections). We find that silica redistribution generally has insignificant effects on host rock and canister temperatures, pore pressures, or flow velocites.
Date: November 1, 1985
Creator: Verma, A. & Pruess, K.
Partner: UNT Libraries Government Documents Department

Effects of wigglers and undulators on beam dynamics

Description: Synchrotron light facilities are making ever increasing use of wigglers and undulators, to the extent that these devices are becoming a significant part of the beam optical system of the storage ring itself. This paper presents a theoretical formulation for investigating the effect of wigglers and undulators on beam dynamics in the approximation that the wiggler parameter, K, divided by ..gamma.. is a small number and that the number of wiggler periods in one device is large. In addition to the linear forces which must be taken into account when tuning and matching the ring, nonlinear stop bends are created, with even orders more serious than odd orders. Some numerical examples are given for devices similar to those proposed for the 1-2 GeV Synchrotron Radiation Source at Lawrence Berkeley Laboratory.
Date: August 1, 1986
Creator: Smith, L.
Partner: UNT Libraries Government Documents Department

Development of an array of cooled large area Si(Li) detectors

Description: A system containing six cooled, 34 mm diam by 7 mm thick, high-resolution Si(Li) detectors designed to maximize the sensitivity for counting x rays in the 10-30 keV range to measure trace radionuclides in soil samples has been successfully fabricated. The detectors were mounted in a paddle-shaped cryostat with a single large beryllium window on each side. This configuration provides for efficient anticoincidence background suppression and effectively doubles the sensitive detector area because x rays can impinge on the detectors from both sides. To maximize detection efficiency, the thickness of the cryostat was held to a bare minimum (25 mm); this caused severe difficulties during fabrication of the system. Cutting down the rim of the detectors reduced to an acceptable level the microphony caused by movement of the beryllium window that faces the lithium-diffused contact of the detectors. Since this system will be used for low level counting. careful testing was performed to select materials having the lowest radioactivity.
Date: October 1, 1985
Creator: Pehl, R.H.; Madden, N.W.; Walton, J.T.; Malone, D.F.; Landis, D.A.; Goulding, F.S. et al.
Partner: UNT Libraries Government Documents Department

Design and characterization for absolute x-ray spectrometry in the 100-10,000 eV region

Description: Reviewed here are the design and characterization procedures used in our program for developing absolute x-ray spectrometry in the 100 to 10,000 eV region. Described are the selection and experimental calibration of the x-ray filters, mirror momochromators, crystal/multilayer analyzers, and the photographic (time integrating) and photoelectric (time resolving) position-sensitive detectors. Analytical response functions have been derived that characterize the energy dependence of the mirror and crystal/multilayer reflectivities and of the photographic film and photocathode sensitivities. These response functions permit rapid, small-computer reduction of the experimental spectra to absolute spectra (measured in photons per stearadian from the source for radiative transitions at indicated photon energies). Our x-ray spectrographic systems are being applied to the diagnostics of pulsed, high temperature plasma sources in laser fusion and x-ray laser research. 15 refs., 27 figs.
Date: August 1, 1986
Creator: Henke, B.L.
Partner: UNT Libraries Government Documents Department

Advanced concepts for acceleration

Description: Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)
Date: July 1, 1986
Creator: Keefe, D.
Partner: UNT Libraries Government Documents Department

Lie algebraic methods for particle tracking calculations

Description: A study of the nonlinear stability of an accelerator or storage ring lattice typically includes particle tracking simulations. Such simulations trace rays through linear and nonlinear lattice elements by numerically evaluating linear matrix or impulsive nonlinear transformations. Using the mathematical tools of Lie groups and algebras, one may construct a formalism which makes explicit use of Hamilton's equations and which allows the description of groups of linear and nonlinear lattice elements by a single transformation. Such a transformation will be exactly canonical and will describe finite length linear and nonlinear elements through third (octupole) order. It is presently possible to include effects such as fringing fields and potentially possible to extend the formalism to include nonlinearities of higher order, multipole errors, and magnet misalignments. We outline this Lie algebraic formalism and its use in particle tracking calculations. A computer code, MARYLIE, has been constructed on the basis of this formalism. We describe the use of this program for tracking and provide examples of its application. 6 references, 3 figures.
Date: August 1, 1983
Creator: Douglas, D.R. & Dragt, A.J.
Partner: UNT Libraries Government Documents Department

Gluon bremstrahlung effects in large P/sub perpendicular/ hadron-hadron scattering

Description: We consider effects of parton (primarily gluon) bremstrahlung in the initial and final states of high transverse momentum hadron-hadron scattering. Monte Carlo calculations based on conventional QCD parton branching and scattering processes are presented. The calculations are carried only to the parton level in the final state. We apply the model to the Drell-Yan process and to high transverse momentum hadron-hadron scattering triggered with a large aperture calorimeter. We show that the latter triggers are biased in that they select events with unusually large bremstrahlung effects. We suggest that this trigger bias explains the large cross section and non-coplanar events observed in the NA5 experiment at the SPS.
Date: February 1, 1982
Creator: Fox, G.C. & Kelly, R.L.
Partner: UNT Libraries Government Documents Department

3-body final states in peripheral heavy-ion collisions: nuclear clustering structure and projectile excitation revisited

Description: Even though peripheral heavy-ion collisions are less violent than their central counterparts, the large energy exchange between the reactants often leaves the primary products in excited particle-unstable states whose subsequent decay leads to 3 or more nuclei emerging in the final exit channel. These post-reaction, predominantly sequential de-excitation processes can sometimes provide interesting structural information about the parent nuclei. In fact, provided these processes are well understood, one can employ them as probes for studying initial properties of the fragments. This report discusses results of two experiments that deal with (1) nonstatistical, rare decay modes of the projectile, and (2) internal excitation energy of the projectile- and target-like fragments in peripheral collisions. The physics addressed in each is different, but the experimental and data-analysis techniques are so similar that it is relevant to join them together.
Date: February 1, 1986
Creator: Chan, Y.; Chavez, E.; Gazes, S.B.; Kamermans, R.; Schmidt, H.R.; Siwek-Wilczynska, J. et al.
Partner: UNT Libraries Government Documents Department

Measurements of cross sections relevant to. gamma. -ray line astronomy

Description: Gamma-ray production cross sections have been measured for the ..gamma..-ray lines which are mostly strongly excited in the proton bombardment of C, O, Mg, Si, and Fe targets of natural isotopic composition. High resolution germanium detectors were used to collect ..gamma..-ray spectra at proton bombarding energies of 20, 30, 33, 40 and 50 MeV. 6 refs., 6 figs.
Date: June 1, 1986
Creator: Lesko, K.T.; Norman, E.B.; Larimer, R.M. & Crane, S.G.
Partner: UNT Libraries Government Documents Department

Annealing of interstitial loops in arsenic implanted silicon

Description: The annealing effect of different gas ambient (N/sub 2/ or O/sub 2/) on high dose (5 x 10/sup 15/) As-ion-implanted Si wafer has been investigated by using transmission electronic microscope. A two-layer defect structure is observed. The lower layer defects are interstitial type and attributed to the amorphous island below original crystalline-amorphous interface. The upper layer loops are As precipitation in the form of stacking fault. By comparing the growth/shrinkage rate of interstitial loops during neutral and oxygen annealing, it is proved that interstitial silicons are injected into bulk silicon during oxidation.
Date: May 1, 1983
Creator: Wu, N.R.; Ling, P.; Sadana, D.K.; Washburn, J. & Current, M.I.
Partner: UNT Libraries Government Documents Department

Transfer and breakup reactions at intermediate energies

Description: The origin of the quasi-elastic peak in peripheral heavy-ion reactions is discussed in terms of inelastic scattering and transfer reactions to unbound states of the primary projectile-like fragment. The situation is analogous to the use of reverse kinematics in fusion reactions, a technique in which the object of study is moving with nearly the beam velocity. It appears that several important features of the quasi-elastic peak may be explained by this approach. Projectile-breakup reactions have attractive features for the study of nuclear structure. They may also be used to determine the partition of excitation energy in peripheral reactions. At intermediate energies, neutron-pickup reactions leading to four-body final states become important. Examples of experiments are presented that illustrate these points. 15 refs., 14 figs.
Date: April 1, 1986
Creator: Stokstad, R.G.
Partner: UNT Libraries Government Documents Department

Fracture mapping in the ventilation drift at Stripa: procedures and results

Description: Detail maps of the fracture system in the ventilation drift at the Stripa mine have been prepared. The procedures used in preparing the maps of the floor and walls of the ventilation drift are documented in this report. The fracture data presented in the detailed maps are heavily supplemented by a coded data file. Each discrete fracture, vein, or fracture zone has been identified by a number on the map and this number has been used to link the map to the data file. This approach permits maximum use of the fracture data by other researchers interpreting completed and on-going experiments or as an aid in planning and interpreting future experiments. 9 refs., 7 figs., 2 tabs.
Date: March 1, 1981
Creator: Rouleau, A.; Gale, J.E. & Baleshta, J.
Partner: UNT Libraries Government Documents Department

Hadron production in e/sup +/e/sup -/ annihilation. QCD and hadronization

Description: Recent results on hadron production in e/sup +/e/sup -/ annihilation are summarized. The topics included are: (1) inclusive hadron production, (2) comparison of light (u,d,s) and heavy (c,b) quark jets; (3) p - anti p correlations; (4) gluon vs. quark jets; (5) analysis of 3 jet events; (6) measurement of the strong coupling constant ..cap alpha../sub s/; and (7) forward-backward asymmetries of quarks and leptons. Experimental data are compared with predictions of several models to reveal underlying physics. 62 refs., 22 figs.
Date: December 1, 1985
Creator: Yamamoto, H.
Partner: UNT Libraries Government Documents Department

Hadron production at PEP/PETRA

Description: Recent results on hadron production in e/sup +/e/sup -/ annihilation at PEP and PETRA are summarized. The topics included are: (1) inclusive hadron production, (2) gluon vs quark jet, (3) analysis of 3 jet events and (4) p - anti p correlations. Experimental data are compared with predictions of several models to reveal underlying physics. 47 refs., 18 figs.
Date: December 1, 1985
Creator: Yamamoto, H.
Partner: UNT Libraries Government Documents Department

Generation of oxygen, carbon and metallic ion beams by a compact microwave source

Description: A small microwave ion source fabricated from a quartz tube and enclosed externally by a cavity has been operated with different geometries and for various gases in a cw mode. This source has been used to generate oxygen ion beams with energy as low as 5.5 eV. Beam energy spread has been measured to be less than 1 eV. By installing different metal plates on the front extraction electrode, metallic ion beams such as (Be, Cu, Al, etc.) can be produced.
Date: July 1, 1986
Creator: Walther, S.R.; Leung, K.N.; Ehlers, K.W. & Kunkel, W.B.
Partner: UNT Libraries Government Documents Department

Formation of H/sup -/ by charge transfer in alkaline-earth vapors

Description: Progress on the study of H/sup -/ formation by charge transfer in alkaline-earth vapors is reported. The H/sup -/ equilibrium yield in strontium vapor reaches a maximum of 50% at an energy of 250 eV/amu, which is the highest H/sup -/ yield reported to date.
Date: October 1, 1983
Creator: Schlachter, A.S. & Morgan, T.J.
Partner: UNT Libraries Government Documents Department

Impedance of a beam tube with antechamber

Description: A beam vacuum chamber was proposed to allow synchrotron light to radiate from a circulating electron beam into an antechamber containing photon targets, pumps, etc. To determine the impedance such a geometry would present to the beam, electromagnetic measurements were carried out on a section of chamber using for low frequencies a current-carrying wire and for up to 16 GHz, a resonance perturbation method. Because the response of such a chamber would depend on upstream and downstream restrictions of aperture yet to be determined, the resonance studies were analyzed in some generality. The favorable conclusion of these studies is that the antechamber makes practically no contribution to either the longitudinal or the transverse impedances.
Date: August 1, 1986
Creator: Barry, W.; Lambertson, G.R. & Voelker, F.
Partner: UNT Libraries Government Documents Department

LBL/UCSB /sup 76/Ge double beta decay experiment: first results

Description: A paper given at the IEEE Nuclear Science Symposium last year presented the scientific justification for this experiment and discussed the design of the detector system. At the present time two of the dual detector systems (i.e., four out of a final total of eight detectors) are operating in the complete active/passive shield in the low background laboratory at LBL. Early results (1620 h) of an experiment using two detectors yield a limit of 4 x 10/sup 22/ years (68% confidence) for the half life of the neutrinoless double beta decay (..beta beta../sub o nu/) of /sup 76/Ge. Although this experiment was carried out above ground, the result approaches those achieved by other groups in deep underground laboratories. Based on studies of the origins of background in our system, we hope to reach a limit of 3 x 10/sup 23/ years (or more) in a two month/four detector experiment to be carried out soon in an underground facility.
Date: October 1, 1984
Creator: Goulding, F.S.; Cork, C.P.; Landis, D.A.; Luke, P.N.; Madden, N.W.; Malone, D.F. et al.
Partner: UNT Libraries Government Documents Department

Reinjection into geothermal reservoirs

Description: Reinjection of geothermal wastewater is practiced as a means of disposal and for reservoir pressure support. Various aspects of reinjection are discussed, both in terms of theoretical studies as well as specific field examples. The discussion focuses on the major effects of reinjection, including pressure maintenance and chemical and thermal effects. (ACR)
Date: August 1, 1987
Creator: Bodvarsson, G.S. & Stefansson, V.
Partner: UNT Libraries Government Documents Department