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Electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole channel

Description: This work studies the electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole field for a free-electron laser (FEL) that will be operated in the VUV or XUV wavelength region. The quadrupole field is assumed to vary continuously along the symmetry axis. The linearized equations of electron motion are solved analytically by using the two-scale perturbation method for a plane polarized wiggler. The electron-beam envelopes and the envelope equations, as well … more
Date: January 1, 1985
Creator: Wang, T. F. & Cooper, R. K.
Partner: UNT Libraries Government Documents Department
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Energy conservation potential of surface modification technologies

Description: This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.
Date: September 1, 1985
Creator: Le, H.K.; Horne, D.M. & Silberglitt, R.S.
Partner: UNT Libraries Government Documents Department
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Observation of high-power millimeter wave emission from a virtual cathode

Description: Intense bursts of mm wave power have been observed in microwave generation experiments with a relativistic electron beam (REB) virtual cathode oscillator. In this device an electron beam is injected into a drift space at a current above the space-charge-limit, and a potential develops downstream which is large enough to reflect electrons back to the source region. Two mechanisms can give rise to microwave oscillations in a virtual cathode device: electrons reflexing between the real and virtual… more
Date: January 1, 1985
Creator: Davis, H. A.; Bartsch, R. R.; Sherwood, E. G.; Stringfield, R. M. & Thode, L. E.
Partner: UNT Libraries Government Documents Department
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Summary of the working group on the construction and demonstration of a Siberian Snake

Description: It was recognized as long ago as the 1977 Ann Arbor Meeting on Higher Energy Polarized Proton Beams that a ''Siberian Snake'' should be built and tested in an operating accelerator. A program to accomplish this at Argonne National Laboratory (ANL) was part of a proposal to DOE to construct a small R and D accelerator at ANL. This was never implemented and between then and now many theory papers have been written but no Proof of Principle Experiment (POPE) has been done. The present Ann Arbor wo… more
Date: January 1, 1985
Creator: Ratner, L. G. & Raylman, R. R.
Partner: UNT Libraries Government Documents Department
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Damage-rate gradient effects on radiation-induced segregation and phase stability in irradiated alloys

Description: Recent studies have shown that significant compositional redistribution in irradiated alloys can be induced by the gradients in the atomic displacement rates resulting from nonuniform defect production, in addition to the commonly-observed solute segregation at defect sinks. This process gives rise to complex local phase transformations during light-ion bombardment or irradiation with focused electron beams in the high-voltage electron microscope. Results of our theoretical and experimental inv… more
Date: July 1, 1985
Creator: Lam, N.Q. & Okamoto, P.R.
Partner: UNT Libraries Government Documents Department
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Neutron diffraction studies of thin film multilayer structures

Description: The application of neutron diffraction methods to the study of the microscopic chemical and magnetic structures of thin film multilayers is reviewed. Multilayer diffraction phenomena are described in general and in particular for the case in which one of the materials of a bilayer is ferromagnetic and the neutron beam polarized. Recent neutron diffraction measurements performed on some interesting multilayer systems are discussed. 70 refs., 5 figs.
Date: January 1, 1985
Creator: Majkrzak, C.F.
Partner: UNT Libraries Government Documents Department
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Electromagnetic Effects in Relativistic Electron Beam Plasma Interactions

Description: Electromagnetic effects excited by intense relativistic electron beams in plasmas are investigated using a two-dimensional particle code. The simulations with dense beams show large magnetic fields excited by the Weibel instability as well as sizeable electromagnetic radiation over a significant range of frequencies. The possible relevance of beam plasma instabilities to the laser acceleration of particles is briefly discussed. 6 refs., 4 figs.
Date: February 13, 1985
Creator: Kruer, W. L. & Langdon, A. B.
Partner: UNT Libraries Government Documents Department
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Coherent instability and ion trapping considerations for Aladdin lattices

Description: This paper presents the results of an investigation of the effects of ions and coherent collective instabilities on bunched electron beams circulating in the various Aladdin lattices considered in the Aladdin Upgrade Study. It is aimed particularly at identifying those collective and ion phenomena that may be limiting the performance of the present Aladdin with low energy (100 MeV) injection, at ascertaining which of these phenomena would still remain and limit the performance with a full energ… more
Date: May 1, 1985
Creator: Chattopadhyay, S.
Partner: UNT Libraries Government Documents Department
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Crossing simple resonances

Description: A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances.
Date: August 1, 1985
Creator: Collins, T.
Partner: UNT Libraries Government Documents Department
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Effects of space charge on the acceptance of brightness measuring devices

Description: Attempts to measure high electron beam brightness at low values of beam energy are plagued by the effects of space charge forces. These forces can substantially lower the phase space acceptance of various brightness measuring devices. This report considers several models for the effects of space charge upon the acceptance of both the field free, double aperture system and the magnetic ''emittance selector'' and compares them for some recent experiments on ATA and the High Brightness Test Stand.… more
Date: August 14, 1985
Creator: Caporaso, G.J.
Partner: UNT Libraries Government Documents Department
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Determination of sin/sup 2/THETA/sub w/ and rho in deep inelastic neutrino-nucleon scattering

Description: We have determined the electroweak parameters sin/sup 2/THETA/sub w/ and rho by a measurement of deep inelastic neutrino-nucleon scattering using a fine grained neutrino detector exposed to a narrow band neutrino beam at Fermilab. The unique sampling properties of our detector have permitted neutral current and charged current events to be unambiguously identified over a wide kinematic range, thereby allowing a determination of sin/sup 2/THETA/sub w/ and rho to be made with good statistics and … more
Date: June 1, 1985
Creator: Bogert, D.; Burnstein, R.; Fisk, R.; Fuess, S.; Morfin, J.; Ohska, T. et al.
Partner: UNT Libraries Government Documents Department
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Remote recovery of irradiated tensile samples incapsulated in Pb-Bi

Description: The Swiss Institute for Nuclear Research (SIN) is upgrading their proton accelerator to 1 to 2 mA Beam current at 600 MeV. Molten Pb-Bi is being considered as a beam stop. The materials in the beam stop must be chemically compatible with molten Pb-Bi, retain ductility and strength, and have a lifetime of at least six months. In a joint venture between the United States and SIN, four capsules were designed and loaded with eight tensile samples. The tensile samples were Ta, Cr (Fe-2 1/4% Cr-1% Mo… more
Date: January 1, 1985
Creator: Nicol, A. G.; Brown, R. D. & Cook, J. H.
Partner: UNT Libraries Government Documents Department
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Importance of high order momentum terms in SLC optics

Description: The evaluation of background levels at the SLC relies, in several cases, on the proper representation of how low momentum electrons propagate through the Arcs and the Final Focus System (FFS). For example, beam - gas bremsstrahlung in the arcs causes electrons of up to 6% energy loss to be transported through to the IP; secondary showers on edges of masks and collimators yield debris with a very wide momentum spectrum. This note is a naive attempt at checking the validity of TRANSPORT and TURTL… more
Date: July 10, 1985
Creator: Kozanecki, W.
Partner: UNT Libraries Government Documents Department
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CBEAM. 2-D: a two-dimensional beam field code

Description: CBEAM.2-D is a two-dimensional solution of Maxwell's equations for the case of an electron beam propagating through an air medium. Solutions are performed in the beam-retarded time frame. Conductivity is calculated self-consistently with field equations, allowing sophisticated dependence of plasma parameters to be handled. A unique feature of the code is that it is implemented on an IBM PC microcomputer in the BASIC language. Consequently, it should be available to a wide audience.
Date: May 1, 1985
Creator: Dreyer, K. A.
Partner: UNT Libraries Government Documents Department
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Report of the workshop on low-temperature neutron irradiation

Description: This Workshop was held at Oak Ridge National Laboratory May 29-31, 1985, to aid in preparing for the use of the National Low-Temperature Neutron Irradiation Facility (NLTNIF), which is being built at the Bulk Shielding Reactor at Oak Ridge National Laboratory and is scheduled to be ready for experiments late in 1985. NLTNIF will be operated as a user facility, with no cost to users for the irradiations for approved experiments. Purposes of the Workshop were to review research areas for which NL… more
Date: January 1, 1985
Partner: UNT Libraries Government Documents Department
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Numerical simulation of an accelerator injector

Description: Accelerator injector designs have been evaluated using two computer codes. The first code self consistently follows relativistic particles in two dimensions. Fields are obtained in the Darwin model which includes inductive effects. This code is used to study cathode emission and acceleration to full injector voltage. The second code transports a fixed segment of a beam along the remainder of the beam line. Using these two codes the effects of electrode configuration on emittance, beam quality a… more
Date: May 9, 1985
Creator: Boyd, J.K.; Caporaso, G.J. & Cole, A.G.
Partner: UNT Libraries Government Documents Department
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Initial measurements of beam breakup instability in the advanced test accelerator

Description: This paper reports the measurements of beam breakup (BBU) instability performed on the Advanced Test Accelerator (ATA) up to the end of February, 1984. The main objective was to produce a high current usable electron beam at the ATA output. A well-known instability is BBU which arises from the accelerator cavity modes interacting with the electron beam. The dominant mode is TM/sub 130/ at a frequency of approximately 785 MHz. It couples most strongly to the beam motion and has been observed to … more
Date: May 13, 1985
Creator: Chong, Y.P.; Caporaso, G.J. & Struve, K.W.
Partner: UNT Libraries Government Documents Department
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Time-resolved current, current-density, and emittance measurements of the PHERMEX electron beam

Description: The PHERMEX electron-beam pulse is a burst of ten 3.3-ns micropulses separated by 20 ns. Typical accelerator operating parameters produce a mean beam micropulse energy of 26 MeV with peak current of 300-500 A. The purpose of this work is to present experimental measurements of the current, current density, and emittance of a single PHERMEX micropulse. This experiment is part of an effort to completely characterize the PHERMEX electron beam. Understanding the electron-beam parameters is necessar… more
Date: January 1, 1985
Creator: Moir, D.C.; Builta, L.A. & Starke, T.P.
Partner: UNT Libraries Government Documents Department
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Effects of slots/holes in disks on frequencies of TM/sub 01/ and EH/sub 11/ waves in the disk-loaded waveguide

Description: The increase in the BBU threshold current is very important for the high and medium energy electron linacs because of a larger operating current attainable or a smaller emittance available at certain operating current. For this purpose, many means can be used, among which the improvement in the accelerating structure itself is always fundamental. SLAC's three-meter long section is unique with truly constant gradient performance. The theoretical analyses and operating experiences at SLAC have in… more
Date: March 1, 1985
Creator: Yao, C.G.
Partner: UNT Libraries Government Documents Department
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Interaction of the ATA beam with the TM/sub 030/ mode of the accelerating cells

Description: The interaction of the electron beam in the Advanced Test Accelerator with an azimuthally symmetric mode of the accelerating cells is investigated theoretically. The interaction possibly could cause modulation of the beam current at the resonant frequency of the mode. Values of the shunt impedance and Q value of the mode were obtained from previous measurement and analysis. Lagranian hydrodynamics is employed and a WKB solution to the equation of motion is obtained. Results indicate that the in… more
Date: February 14, 1985
Creator: Neil, V.K.
Partner: UNT Libraries Government Documents Department
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Determination of the nucleon structure using the weak neutral current

Description: An experimental determination of the neutral current structure functions of the nucleon is obtained by measuring the ratio of the neutral current x distribution to the charged current x distribution. The analysis is based on deep inelastic neutrino nucleon scattering data gathered in a massive fine-grained neutrino detector exposed to a narrow band neutrino beam at Fermilab. 12 refs., 2 figs., 2 tabs.
Date: July 1, 1985
Creator: Bogert, D.; Burnstein, R.; Fisk, R.; Fuess, S.; Morfin, J. G.; Ohska, T. et al.
Partner: UNT Libraries Government Documents Department
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IPNS Chopper Control and Accelerator Interface Systems

Description: Several of the instruments at the Intense Pulsed Neutron Source (IPNS) at Argonne use rotating Fermi choppers. The techniques used to control the speed and phase of these rotating devices are discussed.
Date: January 1, 1985
Creator: Ostrowski, G. E.; Donley, L. I.; Rauchas, A. V.; Volk, G. J.; Jung, E. A.; Haumann, J. R. et al.
Partner: UNT Libraries Government Documents Department
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Brightness measurements on the Livermore high brightness test stand

Description: Several techniques using small radius collimating pipes with and without axial magnetic fields to measure the brightness of an extracted 1 - 2 kA, 1 - 1.5 MeV electron beam will be described. The output beam of the High Brightness Test Stand as measured by one of these techniques is in excess of 2 x 10/sup 5/ amp/cm/sup 2//steradian. 5 refs., 4 figs.
Date: May 9, 1985
Creator: Caporaso, G.J. & Birx, D.L.
Partner: UNT Libraries Government Documents Department
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