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Beam loading and cavity compensation for the ground test accelerator

Description: The Ground Test Accelerator (GTA) will be a heavily beam-loaded H/sup minus/ linac with tight tolerances on accelerating field parameters. The methods used in modeling the effects of beam loading in this machine are described. The response of the cavity to both beam and radio-frequency (RF) drive stimulus is derived, including the effects of cavity detuning. This derivation is not restricted to a small-signal approximation. An analytical method for synthesizing a predistortion network that deco… more
Date: January 1, 1989
Creator: Jachim, S.P. & Natter, E.F.
Item Type: Refine your search to only Article
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Beam loading and emittance growth for a disk-loaded structure scaled to 10. mu. m

Description: Beam loading and transverse emittance growth are studied in a disk-loaded accelerating structure which has been scaled to a wavelength of 10 ..mu..m. The resulting limitations on the charge per bunch which can be accelerated in such a scaled structure should provide a crude estimate of the charge per bunch which can be accelerated in a laser driven grating accelerator operating at the same wavelength. For an accelerator 100 m in length delivering an energy of 500 GeV, it is found that the numbe… more
Date: May 1, 1982
Creator: Wilson, Perry B.
Item Type: Refine your search to only Article
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Beam loss by collimation in a neutralizer duct

Description: Beam fractions lost by collimation in a neutralizer duct are computed in x-x' phase space by using three examples of slab beam distributions under a broad range of duct dimensions, beam half-widths, and beam divergences. The results can be used to design compact neutralizers and to specify beam requirements. The computer code ILOST can be used under a broad range of beam conditions to compute the fraction lost by collimation.
Date: April 3, 1980
Creator: Hamilton, G.W. & Willmann, P.A.
Item Type: Refine your search to only Report
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Beam-loss monitors in the SLC Final Focus

Description: Beam-loss monitors in the SLC Final Focus System are used for protection of accelerator and detector components, optimizing adjustment of beam halo collimators, and as diagnostics of beam size and halo. Construction of a variety of monitors based on discrete ion chambers, proportional tubes, continuous ion chambers, and signals from the Mark II detector is reported. The interfaces to the SLC control system, the Mark II detector data acquisition system, and the SLC machine protection system are … more
Date: March 1989
Creator: Jacobsen, R. G. & Mattison, T.
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Beam measurements on Argonne linac for collider injector design

Description: The 20 MeV electron linac at Argonne produces 5 x 10/sup 10/ electrons in a single bunch. This amount of charge per bunch is required for the proposed single pass collider at SLAC. For this reason the characteristics of the beam from this machine are of interest. The longitudinal charge distribution has been measured by a new technique. The technique is a variation on the deduction of bunch shape from a spectrum measurement. Under favorable conditions a resolution of about 1/sup 0/ of phase is … more
Date: July 1, 1980
Creator: James, M. B.; Koontz, R. F. & Miller, R. H.
Item Type: Refine your search to only Article
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Beam model for non-planar orbits in synchrotrons

Description: A framework has been developed for a beam model in the case of synchrotron orbits not confined to a plane. An appropriate moving reference system for the analysis of beam stability has been introduced. As examples of strong perturbations to median plane symmetry, two geometries for the overpass for the Tevatron collider are considered.
Date: March 26, 1984
Creator: Month, M.
Item Type: Refine your search to only Report
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A beam-modification assembly for experimental neutron capture therapy of brain tumors

Description: Recent attempts to treat intracerebral rat gliomas by boron neutron capture therapy (BNCT) have been somewhat disappointing, perhaps in part because of excessive whole-body and nasopharyngeal irradiation. Intracerebral rat gliomas were treated by BNCT with more success using a new beam-modification assembly. 3 refs., 2 figs.
Date: January 1, 1989
Creator: Slatkin, D. N.; Kalef-Ezra, J. A.; Saraf, S. K. & Joel, D. D.
Item Type: Refine your search to only Article
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Beam optical properties of the NSLS dipoles

Description: Presently there is much interest in low energy (<1 GeV) electron storage rings as sources of synchrotron radiation and for studies of the free electron laser. The economics and physics of these storage rings favor the use of bending magnets with small radius of curvature and large bend angle. Some general features of such magnets and the results of magnetic measurements of the dipole magnets of the NSLS booster and storage rings are discussed. The magnetic measurements are interpreted in terms … more
Date: January 1, 1981
Creator: Galayda, J. N.; Blumberg, L. N.; Heese, R. N. & Hsieh, H. C. H.
Item Type: Refine your search to only Report
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Beam optics in the FXR 1. 5 MeV, 4 kA injector

Description: The 20 MeV, 4 kA linear induction accelerator (FXR), currently under construction at LLNL, will use a cold cathode injector. The foil cathode consists of a 0.03 mm tantalum ribbon wound in a spiral with successive turns spaced 0.8 mm apart. The emitted current will be 15 to 20 kA but will be reduced to 4 kA by collimating immediately beyond the anode. This will minimize the beam emittance and maintain a good impedance match with the low impedance driving source. Computer simulation was used ext… more
Date: January 1, 1981
Creator: Scarpetti, R.D.; Kuenning, R.W. & Wong, K.C.
Item Type: Refine your search to only Article
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The beam optics of the Argonne Positive-Ion Injector

Description: The beam optics for Phase I of the Argonne Positive-Ion Injector linac system have been studied for a representative set of beams. The results of this study indicate that high charge state beams from an ECR source can be accelerated without significantly increasing the transverse or longitudinal emittance of the initial beam. It is expected that the beam quality from the PII-ATLAS system will be at least as good as presently achieved with the tandem-ATLAS system.
Date: January 1, 1987
Creator: Pardo, R.C.; Shepard, K.W. & Karls, M.
Item Type: Refine your search to only Article
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Beam parametr measurements for the SLAC linear collider

Description: A stable, closely-controlled, high-intensity, single-bunch beam will be required for the SLAC Linear Collider. The characteristics of short-pulse, low-intensity beams in the SLAC linac have been studied. A new, high-intensity thermionic gun, subharmonic buncher and S-band buncher/accelerator section were installed recently at SLAC. With these components, up to 10/sup 11/ electrons in a single S-band bunch are available for injection into the linac. the first 100-m accelerator sector has been mo… more
Date: January 1, 1981
Creator: Clendenin, J. E.; Blocker, C. & Breidenbach, M.
Item Type: Refine your search to only Article
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Beam pipe design, wall-heating, and collective instability constraints for LAMPF II

Description: The rapidly changing magnetic fields of the LAMPF II rapid-cycling synchrotron will induce electric fields that will induce ohmic heating by wall currents in a beam pipe placed within these rapidly changing fields. A conducting beam pipe is required to remove high-frequency collective instabilities. Some compromise in design is required so that a beam pipe with low conductivity at the LAMPF II cycling frequency (f = 30 to 60 Hz) and high conductivity at high frequencies (f greater than or equal… more
Date: August 1, 1984
Creator: Neuffer, David
Item Type: Refine your search to only Report
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Beam-position measurement system at the Argonne Rapid-Cycling Synchrotron

Description: The position measurement system for the Rapid-Cycling Synchrotron (RCS) was originally designed with a four-plate, combined function, capacitive pickup pi electrode situated in each of the six short straight sections. During subsequent operation, it was discovered that these electrodes were limiting the aperture and, therefore, were being activated by the circulating proton beam. In addition, the activation made it difficult to maintain the active electronic components in the RCS tunnel. The ne… more
Date: January 1, 1981
Creator: Rauchas, A. V.; Brumwell, F. R.; Cho, Y. & Czyz, W. S.
Item Type: Refine your search to only Article
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Beam position monitor analysis

Description: A large proportion of devices used to interact with charged-particle beams in accelerator or storage rings can be classified as pick-ups or kickers. These devices extract information about the particle motion or affect a change in the motion. One device used frequently as pick-up or kicker is made with two little plates with one or more terminations per plate. In this paper the structure with one termination per plate is examined. The azimuthal dependence is taken into account in circular geome… more
Date: March 1, 1989
Creator: Di Massa, G. & Ruggiero, A. G.
Item Type: Refine your search to only Report
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Beam position monitor readout and control in the SLC linac

Description: A beam position monitoring system has been implemented in the first third of the SLC linac which provides a complete scan of the trajectory on a single beam pulse. The data is collected from the local micro-computers and viewed with an updating display at a console or passed on to application programs. The system must operate with interlaced beams so the scans are also interlaced, providing each user with the ability to select the beam, the update rate, and the attenuation level in the digitizi… more
Date: April 1, 1985
Creator: Bogart, J.; Phinney, N.; Ross, M. & Yaffe, D.
Item Type: Refine your search to only Article
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Beam position monitor system for storage rings

Description: Beam position monitors (BPM) for synchrotron light storage rings usually consist of beam pickup electrodes, coaxial relays and a narrowband receiver. While accurate, these systems are slow and of limited use in the commissioning of an accelerator. A beam position monitor is described which is intended to be a principal diagnostic during debug and routine running of a storage ring. It is capable of measuring the position of a single bunch on the first or nth orbit to an accuracy of a few percent… more
Date: May 1, 1985
Creator: Nakamura, M. & Hinkson, J.A.
Item Type: Refine your search to only Article
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Beam position monitor system for the proton storage ring at LAMPF

Description: A high-current Proton Storage Ring (PSR) is being constructed at Los Alamos to accumulate intense pulses of 800-MeV protons from LAMPF for delivery to neutron production targets. The beam's transverse location in the injection channel, ring, and extraction channel will be determined by a beam position monitor (BPM) system. The beam will be detected by stripline sensors that generate 4-quadrant position signals from the spectral components of the beam. Sixty sensors are planned for the installat… more
Date: January 1, 1981
Creator: Higgins, E. F. & Wells, F. D.
Item Type: Refine your search to only Article
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Beam position monitor upgrade for the Los Alamos Proton Storage Ring

Description: The beam diagnostics for the Los Alamos Proton Storage Ring (PSR) are being upgraded in several areas, including the closed-orbit beam position system, the high-frequency longitudinal and transverse beam diagnostics, and the extraction-line beam-position monitoring system. This paper describes the basic design of these new systems. 4 refs., 3 figs.
Date: January 1, 1989
Creator: Shafer, R. E.; Swain, G.; Thiessen, H. A.; Macek, R.; Mackenzie, G. & Rawnsley, W.
Item Type: Refine your search to only Article
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Beam-Profile Measurement of Laser Pulses Using a Spatial Filter to Sample the Hermite Modes of a String of Pulses

Description: Abstract: As a first step in the development of a beam-profile measuring instrument for laser sources that is capable of determining the distribution of low-order (less than 25) Hermitian modes in a series of laser pulses, I designed and evaluated the three key parts of such an instrument. First, there is the telescope system which allows the incident laser beam to be phase, beamwidth, and beam center matched to the optical spatial filter. Second, there is a brief error analysis of the structur… more
Date: September 1982
Creator: Johnson, Eric Gunnar, Jr.
Item Type: Refine your search to only Report
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Beam-profile measurement on the magnetoelastic microscope

Description: A proof-of-principle magnetoelastic lens has been shown to behave much as expected. Calibration of its behavior has been achieved in a relatively simple and repeatable way. The relatively good agreement with the magnetoelastic optics model gives rise to the hope that focusing of the internal field will ultimately give rise to diffraction limited operation; that is, to about 4 ..mu..m for shear wave operation at 1.0 GHz. (MOW)
Date: January 1, 1981
Creator: Bongianni, W.L.
Item Type: Refine your search to only Article
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