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in subjects: "Beam Transport"

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Survey techniques developed to align stacked beamlines at CEBAF

The Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News, Virginia is a new accelerator designed to produce 4 GeV 200 micro-amp continuous wave beams for nuclear physics research. It consists of two superconducting linacs each accelerating electrons by 400 MeV and linked by arcs allowing five pass recirculation. These linacs form the straight sections in a racetrack shaped accelerator contained in over 1.3 km of tunnel. The beam lines will consist of 42 superconducting accelera… more

Date: April 1, 1994

Creator: Curtis, C. J.; Oren, W. & Tremblay, K. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Intense electron-beam transport in the ion-focused regime through the collision-dominated regime

This paper reviews the transport of the 19-MeV, 700-kA, 25-ns Hermes-III electron beam in long gas cells filled with N{sub 2} gas spanning six decades in pressure from 10{sup 3} to {approximately}10{sup 3} Torr. We show through measurements and theoretical analyses that the beam has two windows of stable transport: a low-pressure window (between {approximately}1 and {approximately}100 mTorr) that is dominated by propagation in the semi-collisionless IFR (ion-focused regime), and a high-pressure… more

Date: December 31, 1993

Creator: Sanford, T. W. L.; Poukey, J. W.; Welch, D. R. & Mock, R. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

CEBAF Beam Transport Magnet Power Supply Control System

The CEBAF beam transport magnet power supplies must satisfy tight repeatability, stability and availability constraints under relatively severe environmental conditions. The control system described allows these constraints to be satisfied in a straight forward fashion by permitting the embedding of all sensitive signals and components in the power supply itself and using a serial interface between the CAMAC based control system and the power supply controller interface.

Date: November 1, 1991

Creator: O'Sullivan, Michael; Dobeck, Nicholas; Flood, Roger & Perry, John

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Bent solenoids for spectrometers and emittance exchange sections.

Bent solenoids can be used to transport low energy beams as they provide both confinement and dispersion of particle orbits. Solenoids are being considered both as emittance exchange sections and spectrometers in the muon cooling system as part of the study of the muon collider. They present the results of a study of bent solenoids which considers the design of coupling sections between bent solenoids to straight solenoids, drift compensation fields, aberrations, and factors relating to the con… more

Date: March 26, 1999

Creator: Norem, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Survey and Alignment of High Energy Physics Accelerators and Transport Lines

This talk summarizes the survey and alignment processes of accelerators and transport lines and discusses the propagation of errors associated with these processes. The major geodetic principles governing the survey and alignment measurement space are revisited and their relationship to a lattice coordinate system shown. The paper continues with a broad overview about the activities involved in the step by step sequence from initial absolute alignment to final smoothing. Emphasis is given to th… more

Date: November 1, 1992

Creator: Ruland, R. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental demonstration of relativistic electron cooling

We report on an experimental demonstration of electron cooling of high-energy antiprotons circulating in a storage ring. In our experiments, electron cooling, a well-established method at low energies (< 500 MeV/nucleon), was carried out in a new region of beam parameters, requiring a multi-MeV dc electron beam and an unusual beam transport line. In this letter we present the results of the longitudinal cooling force measurements and compare them with theoretical predictions.

Date: November 1, 2005

Creator: Nagaitsev, S.; Broemmelsiek, D.; Burov, Alexey V.; Carlson, K.; Gattuso, C.; Hu, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Focusing and matching properties of the ATR transfer line

The AGS to RHIC (AtR) beam transfer line has been constructed and will be used to transfer beam bunches from the AGS machine into the RHIC machine which is presently under construction at BNL. The original design of the AtR line has been modified. This article will present the optics of the various sections of the existing AtR beam line, as well as the matching capabilities of the AtR line to the RHIC machine.

Date: July 1, 1997

Creator: Tsoupas, N.; Fischer, W.; Kewisch, J.; MacKay, W. W.; Peggs, S.; Pilat, F. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Overview of the ATR power supplies

The AGS to RHIC transfer line (ATR) transports a variety of beams from the Alternating Gradient Synchrotron (AGS) which gets its input from the Booster Synchrotron. In turn, the Booster receives input beams from either a Tandem Van de Graaff (heavy ions) or a Linac (protons). The AGS extracts beam bunches, up to a rate of 30 Hertz, to the ATR which feeds the Relativistic Heavy Ion Collider (RHIC) starting with the sextant test in January of 1997. The ATR is made up of the upgraded U line and th… more

Date: July 1, 1997

Creator: Bruno, D.; Soukas, A.; Toldo, F. & Lambiase, R.F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Hybrid permanent quadrupoles for the 8 GeV transfer line at Fermilab

Hybrid Permanent Magnet Quadrupoles for specialized portions of the 8 GeV transfer line from the Fermilab Booster to the new Main Injector have been built, tested and installed. These magnets use a 0.635 m long iron shell and provide an integrated gradient of 1.48 T-m/m with an iron pole tip radius of 0.0416 m. and pole length of 0.508 m. Bricks of 0.0254 m thick strontium ferrite supply the flux to the back of the pole to produce the desired 2.91 T/m gradient. For temperature compensation, Ni-… more

Date: June 1, 1997

Creator: Pruss, S. M.; Foster, G. W.; Glass, H. D.; Harding, D. J.; Jackson, G. P.; May, M. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Unexpected matching insensitivity in DTL of GTA accelerator

The Intertank Matching Section (IMS) of the Ground Test Accelerator (GTA) contains four variable-field quadrupoles (VFQs) and is designed to match beam exiting the Radio-Frequency Quadrupole to the first tank of the Drift-tube LINAC (DTL-1). By varying the VFQ field strengths to create a range of beam mismatches at the entrance to DTL-1, one can test the sensitivity of the DTL-1 output beam to variations in the DTL-1 input beam. Experimental studies made during commissioning of the GTA indicate… more

Date: May 1995

Creator: Yuan, V. W.; Gilpatrick, J. D.; Johnson, K. F.; Lysenko, W. P.; Rusthoi, D. P.; Sander, O. R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Optics measurement resolution and BPM errors

We study the impact of BPM resolution on optics measurements at various levels of complexity: (1) Formula linking a given distribution of BPM resolutions to the degree of precision to which any beam trajectory can be determined based on these BPM`s. (2) Formula for the precision achievable in a generalized experimental scheme measuring transfer matrices in the presence of (potentially coupled) orbit errors. (3) Formula constructed from results of (1) and (2) to relate the precision of the trans… more

Date: August 1, 1997

Creator: Chao, Yu-Chiu

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Studies of space-charge effects in ultrashort electron bunches

Laser-driven plasma-based accelerators are capable of producing ultrashort electron bunches in which the longitudinal size is much smaller than the transverse size. We present theoretical studies of the transport of such electron bunches in vacuum. Space charge forces acting on the bunch are calculated using an ellipsoidal bunch shape model. The effects of space charge forces and energy spread on longitudinal and transverse bunch properties are evaluated for various bunch lengths energies and a… more

Date: June 1, 2000

Creator: Fubiani, Gwenael; Leemans, Wim & Esarey, Eric

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Survey techniques developed to align stacked beamlines at CEBAF

Date: January 1, 1994

Creator: Curtis, C. J.; Oren, W. & Tremblay, K. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoret… more

Date: June 4, 2007

Creator: Molvik, A. W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radio-Frequency Beam Conditioner for Fast-Wave Free-Electron Generators of Coherent Radiation

A method for conditioning electron beams is proposed, making use of the TM{sub 210} mode of microwave cavities, to reduce the axial velocity spread within the beam, in order to enhance gain in resonant electron beam devices, such as the free-electron laser (FEL). Effectively, a conditioner removes the restriction on beam emittance. The conditioner is analyzed using a simple model for beam transport and ideal RF cavities. Analysis of an FEL is employed to evaluate performance with reduced axial … more

Date: July 1, 1991

Creator: Sessler, Andrew M.; Whittum, D.H. & Yu, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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AGS Experiments: 1989, 1990, 1991

This report contains: Experimental areas layout; table of beam parameters and fluxes; experiment schedule ``as run``; proposed 1992 schedule; a listing of experiments by number; two-page summaries of each experiment begin here, also ordered by number; publications of AGS Experiments begin here; and list of AGS Experimenters begins here.

Date: February 1, 1992

Creator: Depken, J. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Accelerator and beam transport design information

This report contains viewgraphs on accelerator design and physics.

Date: April 1, 1993

Creator: Lawrence, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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RHIC survey and alignment

The Relativistic Heavy Ion Collider consists of two interlaced plane rings, a pair of mirror-symmetric beam injection arcs, a spatially curved beam transfer line from the Alternating Gradient Synchrotron, and a collection of precisely positioned and aligned magnets, on appropriately positioned support stands, threaded on those arcs. RHIC geometry is defined by six beam crossing points exactly in a plane, lying precising at the vertices of a regular hexagon of specified size position and orienta… more

Date: July 1, 1993

Creator: Karl, F. X.; Anderson, R. R.; Goldman, M. A.; Hemmer, F. M.; Kazmark, D., Jr.; Mroczkowski, T. T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Beam Instrumentation for the Spallation Neutron Source Ring.

The Spallation Neutron Source (SNS) will be constructed by a multi-laboratory collaboration with BNL responsible for the transfer lines and ring. [1] The 1 MW beam power necessitates careful monitoring to minimize un-controlled loss. This high beam power will influence the design of the monitors in the high energy beam transport line (HEBT) from linac to ring, in the ring, and in the ring-to-target transfer line (RTBT). The ring instrumentation must cover a 3-decade range of beam intensity duri… more

Date: March 29, 1999

Creator: Witkover, R. L.; Cameron, P. R.; Shea, T. J.; Connolly, R. C. & Kesselman, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Spectrometer beam tube dimensional optimization

This project examined the optimization of the design of a beam tube. An ANSYS model was used to find the minimum tube thickness and the best camber in a beam tube under vacuum and preloaded by a pair of magnet poles. After the tube was modeled one version of it was built for use in the accelerator. This beam tube was put under a vacuum and the dimensional changes were recorded and compared to the ANSYS predictions. These deflection results were quite close to the predicted numbers and would sug… more

Date: January 4, 1993

Creator: Dye, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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A Fast Optics Orbit Correction Program

No Description Available.

Date: August 1, 1990

Creator: Rossmanith, Robert; Bowling, Bruce; Kewisch, Jorg & Kloeppel, Peter

Item Type: Article

Partner: UNT Libraries Government Documents Department

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INJECTOR PARTICLE SIMULATION AND BEAM TRANSPORT IN A COMPACT LINEAR PROTON ACCELERATOR

A compact Dielectric Wall Accelerator (DWA), with field gradient up to 100 MW/m is being developed to accelerate proton bunches for use in cancer therapy treatment. The injector must create a proton pulse up to several hundred picoseconds, which is then shaped and accelerated with energies up to 250 MeV. The Particle-In-Cell (PIC) code LSP is used to model several aspects of this design. First, we use LSP to obtain the voltage waveform in the A-K gap that will produce a proton bunch with the re… more

Date: June 18, 2007

Creator: Blackfield, D. T.; Chen, Y. J.; Harris, J.; Nelson, S.; Paul, A. & Poole, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A 3-year plan for beam science in the heavy-ion fusion virtual national laboratory

In December 1998, LBNL Director Charles Shank and LLNL Director Bruce Tarter signed a Memorandum of Agreement to create the Heavy-Ion Fusion Virtual National Laboratory (HIF-VNL) with the purpose of improving the efficiency and productivity of heavy ion research through coordination of the two laboratories' efforts under one technical director. In 1999, PPPL Director Robert Goldston signed the VNL MOA for PPPL's heavy-ion fusion group to join the VNL. LBNL and LLNL each contribute about 45% of … more

Date: September 10, 2001

Creator: Logan, B. Grant

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Physics Design Considerations for Diagnostic X Beam Transport System

Diagnostic X (D-X) transport system would extract the beam from the downstream transport line of the second axis of the Dual Axis Radiographic Hydrodynamic Test facility (DARHT-II[1]) and transport this beam to the D-X firing point via four branches of the beamline in order to provide four lines of sight for x-ray radiography. The design goal is to generate four DARHT-II-like x-ray pulses on each line of sight. In this paper, we discuss several potential beam quality degradation processes in th… more

Date: August 1, 2000

Creator: Chen, Y. J. & Paul, A. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department