29 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Collimators"  
Results: 1 - 24 next
open access

LIQUID XENON MULTIWIRE PROPORTIONAL CHAMBERS FOR NUCLEAR MEDICINEAPPLICATIONS

Description: The need for improved spatial resolution in nuclear medicine has long been recognized. Notable attempts to achieve this goal are the gas-filled wire chambers and solid-state detectors. (1) However, at energies above 100 keV, gas-filled chambers suffer from poor detection efficiency and a long recoil electron range in the gas. While it is advantageous to pressurize these chambers to 10 or more atmospheres, structural design of the thin window presents a formidable task. High-resolution optimal c… more
Date: May 1, 1974
Creator: Zaklad, H.; Derenzo, S.E.; Budinger, T.F. & Alvarez, L.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Beam loss handling at the SSC

Description: A scraper/collimation system is required to localize the beam loss in the Collider of the Superconducting Super Collider to a few predefined locations and by doing so to minimize the irradiation of superconducting magnets, to sustain favorable background conditions in the Interaction Regions (IR), and to reduce the impact of radiation on other equipment, personnel, and the environment. Results of full-scale simulation are presented for various systematic and accidental beam loss.
Date: May 1, 1993
Creator: Baishev, I. S.; Drozhdin, A. I. & Mokhov, N. V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electron Cloud at Collimator and Injection Region of the Spallation Neutron Source Accumulator Ring.

Description: The beam loss along the Spallation Neutron Source's accumulator ring is mainly located at the collimator region and injection region. This paper studied the electron cloud build-up at these two regions with the three-dimension program CLOUDLAND.
Date: May 16, 2005
Creator: Wang, L.; Hseuh, H. C.; Lee, Y. Y.; Raparia, D.; Wei, J. & Cousineau, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

BEAM CONTAINMENT SYSTEM FOR NSLS-II

Description: The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indicatio… more
Date: May 23, 2010
Creator: Kramer, S. L.; Casey, W. & Job, P. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Predicting Image Blur in Proton Radiography: Comparisons Between Measurements and Monte Carlo Simulations

Description: Given the cost and lead-times involved in high-energy proton radiography, it is prudent to model proposed radiographic experiments to see if the images predicted would return useful information. We recently modified our raytracing transmission radiography modeling code HADES to perform simplified Monte Carlo simulations of the transport of protons in a proton radiography beamline. Beamline objects include the initial diffuser, vacuum magnetic fields, windows, angle-selecting collimators, and ob… more
Date: May 7, 2010
Creator: Schach von Wittenau, Alexis E.; Aufderheide, Maurice B., III & Henderson, Gary L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Improving the Fermilab Booster Notching Efficiency, Beam Losses and Radiation Levels

Description: A fast vertical 1.08-m long kicker (notcher) located in the Fermilab Booster Long-05 straight section is currently used to remove 3 out of 84 circulating bunches after injection to generate an abort gap. With the maximum magnetic field of 72.5 Gauss, it removes only 87% of the 3-bunch intensity at 400 MeV, with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-06 collimators, and 1% in the rest of the ring. We propose to improve the notching efficiency and reduce beam loss … more
Date: May 14, 2012
Creator: Rakhno, I. L.; Drozhdin, A. I.; Mokhov, N. V.; Sidorov, V. I. & Tropin, I. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Investigation of the radiation background in the interaction region of the medium-energy electron relativisitic heavy ion collider (MeRHIC)

Description: There are three main sources of the radiation background in MeRHIC: forward synchrotron radiation generated upstream of the detector, the direct backward radiation caused by the photons hitting beampipe downstream of the detector, and the indirect secondary radiation caused by hard photons hitting vacuum systems, masks, collimators, absorbers or any other elements in the interaction region. In this paper, we first calculate the primary radiation distribution by employing electromagnetic theory.… more
Date: May 4, 2009
Creator: Beebe-Wang, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Simple Transition-Free Lattice of an 8 GeV Proton Synchroton

Description: A transition-free lattice is a basic requirement of a high-intensity medium-energy (several GeV) proton synchrotron in order to eliminate beam losses during transition crossing. An 8 GeV synchrotron is proposed as a principal component in an alternative hybrid design of Project-X [1]. This machine would be housed in the Fermilab antiproton source enclosure replacing the present Debuncher. A simple doublet lattice with high transition gamma has been designed. It uses just one type of dipoles and… more
Date: May 1, 2009
Creator: Chou, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Residual activation of thin accelerator components

Description: A method to calculate residual activation of thin accelerator components is presented. A model for residual dose estimation for thick objects made of arbitrary composite materials for arbitrary irradiation and cooling times is employed in this study. A scaling procedure is described to apply the model to thin objects with linear dimensions less than a fraction of a nuclear interaction length. The scaling has been performed for various materials and corresponding factors have been determined for… more
Date: May 1, 2006
Creator: Mokhov, N. V.; Rakhno, E. I. & Rakhno, I. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Test Facility for the International Linear Collider at SLAC End Station A, for Prototypes of Beam Delivery and IR Components

Description: The SLAC Linac can deliver damped bunches with ILC parameters for bunch charge and bunch length to End Station A. A 10Hz beam at 28.5 GeV energy can be delivered there, parasitic with PEP-II operation. We plan to use this facility to test prototype components of the Beam Delivery System and Interaction Region. We discuss our plans for this ILC Test Facility and preparations for carrying out experiments related to collimator wakefields and energy spectrometers. We also plan an interaction region… more
Date: May 23, 2005
Creator: Woods, M.; Erickson, R.; Frisch, J.; Hast, C.; Jobe, R. K.; Keller, L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo (T-980)

Description: The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped a… more
Date: May 1, 2010
Creator: Shiltsev, V.; Annala, G.; Drozhdin, A.; Johnson, T.; Legan, A.; Mokhov, N. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Beam Test of a High Pressure Cavity for a Muon Collider

Description: To demonstrate the feasibility of a high pressure RF cavity for use in the cooling channel of a muon collider, an experimental setup that utilizes 400-MeV Fermilab linac proton beam has been developed. In this paper, we describe the beam diagnostics and the collimator system for the experiment, and report the initial results of the beam commissioning. The transient response of the cavity to the beam is measured by the electric and magnetic pickup probes, and the beam-gas interaction is monitore… more
Date: May 1, 2010
Creator: Chung, M.; Jansson, A.; Moretti, A.; Tollestrup, A.; Yonehara, K.; /Fermilab et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Inline Monitors for the SRS Small Column Ion Exchange Process

Description: A Small Column Ion Exchange (SCIX) system, designed by the Oak Ridge and Savannah River National Laboratories (ORNL and SRNL), is a potential way to reduce Cs-137 concentrations in high-level radioactive waste at the Savannah River Site (SRS). SRNL has developed gamma-ray monitors for six locations within the SCIX system to verify the proper operation of the ion exchange system, detect cesium breakthrough, and confirm the presence of cesium before and after used resin is transferred to a grinde… more
Date: May 16, 2005
Creator: Vito, Casella
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

COLLIMATION EXPERIENCE AT RHIC.

Description: In the Relativistic Heavy Ion Collider (RHIC) the abort kicker magnets are the limiting aperture. Continuous losses at this location could deteriorate the kicker performance. In addition, losses especially in the triplet area cause backgrounds in the experimental detectors. The RHIC one-stage collimation system was used to reduce these backgrounds as well as losses at the abort kickers. Collimation performance and results from various runs with even and uneven species (Au-Au, pp and d-Au) are p… more
Date: May 19, 2003
Creator: DREES,K. A. FLILLER,R. TRBOJEVIC,D. KAIN,V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Aerosol-Assisted Solid Debris Collection for the National Ignition Facility

Description: The National Ignition Facility (NIF) has been completed and has made its first shots on-target. While upcoming experiments will be focused on achieving ignition, a variety of subsequent experiments are planned for the facility, including measurement of cross sections, astrophysical measurements, and investigation of hydrodynamic instability in the target capsule. In order to successfully execute several of these planned experiments, the ability to collect solid debris following a NIF capsule sh… more
Date: May 21, 2010
Creator: Nelson, S. L.; Shaughnessy, D. A.; Moody, K. J.; Ivanov, V. V.; Astanovitskiy, A. L.; Lewis, L. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

BEAM DIFFUSION MEASUREMENTS AT RHIC.

Description: During a store, particles from the beam core continually diffuse outwards into the halo through a variety of mechanisms. Understanding the diffusion rate as a function of particle amplitude can help discover which processes are important to halo growth. A collimator can be used to measure the amplitude growth rate as a function of the particle amplitude. In this paper we present results of diffusion measurements performed at the Relativistic Heavy Ion Collider (RHIC) with fully stripped gold io… more
Date: May 12, 2003
Creator: FLILLER,R. P.,IIIDREES,A. GASSNER,D. MCINTYRE,G. PEGGS,S. TRBOJEVIC,D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Beam collimation and machine detector interface at the International Linear Collider

Description: Synchrotron radiation, beam-gas scattering and beam halo interactions with collimators and other components in the ILC beam delivery system (BDS) would create fluxes of muons and other secondaries which could exceed the tolerable levels at a detector by a few orders of magnitude. It is shown that with a multi-stage collimation system, magnetized iron spoilers which fill the tunnel and a set of masks in the detector, one can hopefully meet the design goals. Results of modeling with the STRUCT an… more
Date: May 1, 2005
Creator: Mokhov, N. V.; Drozhdin, A. I. & Kostin, M. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

NEW RESULTS FROM CRYSTAL COLLIMATION AT RHIC.

Description: In this paper, we discuss new results from the use of the crystal collimator from the 2003 run. The yellow ring of the Relativistic Heavy Ion Collider (RHIC) has a bent crystal collimator. By properly aligning the crystal to the beam halo, particles entering the crystal are deflected away from the beam and intercepted downstream in a copper scraper. The purpose of a bent crystal is to improve the collimation efficiency as compared to a scraper alone. We compare these results to previous data, s… more
Date: May 12, 2003
Creator: FLILLER,R. P.,IIIDREES,A. GASSNER,D. HAMMONS,L. MCINTYRE,G. PEGGS,S. TRBOJEVIC,D. BIRYUKOV,V. CHESNOKOV,Y. TEREKHOV,V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Energy deposition issues at 8 GeV H- beam collimation and injection to the Fermilab Main Injector

Description: The energy deposition and radiation issues at 8 GeV h{sup -} beam collimation in the beam transfer line and at stripping injection to the Fermilab Main Injector (MI) are analyzed. Detailed calculations with the STRUCT [1] and MARS15 [2] codes are performed on heating of collimators and stripping foils, as well as on accelerator elements radioactivation at normal operation. Extraction of the unstripped part of the beam to the external beam dump and loss of the excited-state H{sup 0} atoms in MI … more
Date: May 1, 2005
Creator: Drozhdin, A. I.; Kostin, M. A.; Mokhov, N. V. & /Fermilab
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The trajectory control in the SLC linac

Description: Due to wake field effects, the trajectories of accelerated beams in the Linac should be well maintained to avoid severe beam breakup. In order to maintain a small emittance at the end of the Linac, the tolerance on the trajectory deviations become tighter when the beam intensities increase. The existing two beam trajectory correction method works well when the theoretical model agrees with the real machine lattice. Unknown energy deviations along the linac as well as wake field effects can caus… more
Date: May 1, 1991
Creator: Hsu, I. C.; Adolphsen, C. E.; Himel, T. M. & Seeman, J. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Optimizing a nonlinear collimation system for future linear colliders

Description: Experience indicates that beam collimation will be an essential element of the next generation e{sup +}e{sup {minus}} linear colliders. A proposal for using nonlinear lenses to drive beam tails to large amplitudes was presented in a previous paper. Here we study the optimization of such systems including effects of wakefields and optical aberrations. Protection and design of the scrapers in these systems are discussed. 9 refs., 3 figs.
Date: May 1, 1991
Creator: Merminga, N.; Irwin, J.; Helm, R. & Ruth, R. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen