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XTOD to Conventional Facilities Interface Control Document

Description: This document describes the interface between the LCLS X-ray Transport and Diagnostics (XTOD) (WBS 1.5) and the LCLS Conventional Facilities (CF) (WBS 1.1). The interface locations ranging from the beam dump to the far experimental hall are identified. Conventional Facilities provides x-ray, beamline and equipment enclosures, mounting surfaces, conventional utilities, compressed (clean, dry) air, process and purge gases, exhaust systems, power, and environmental conditions for the XTOD components and controls.
Date: September 29, 2005
Creator: McMahon, D
Partner: UNT Libraries Government Documents Department

Notes on dumping gold beam in the AGS

Description: Localized losses of gold beam in the AGS during RHIC Run 8 produced vacuum leaks which required the replacement of several vacuum chambers. A review of what happened and why was given by Leif Ahrens at the Run 8 Retreat. The following notes trace the subsequent development of clean dumping of gold beam on the beam dump in the J10 straight. The novel idea of stripping Au77+ ions in order to put them directly into the upstream face of the dump was introduced by Leif Ahrens and developed by all three of us. George Mahler made the actual stripping device and Dave Gassner developed its control. Leif Ahrens successfully commissioned the device with gold beam during Run 10. The reader may find it helpful to first view the figures herein and then refer to the text for details.
Date: August 1, 2010
Creator: Gardner, C.J.; Ahrens, L. & Thieberger, P.
Partner: UNT Libraries Government Documents Department

The PEP-II abort kicker system

Description: The PEP-II project has two storage rings. The HER (High Energy Ring) has up to 1.48 A of electron beam at 9 GeV, and the LER (Low Energy Ring) has up to 2.14 A of positron beam at 3.1 GeV. To protect the HER and LER beam lines in the event of a ring component failure, each ring has an abort kicker system which directs the beam into a dump when a failure is detected. Due to the high current of the beams, the beam kick is tapered from 100% to 80% in 7.33 uS (the beam transit time around the time). This taper distributes the energy evenly across the window which separates the ring from the beam dump such that the window is not damaged. The abort kicker trigger is synchronized with the ion clearing gap of the beam allowing for the kicker field to rise from 0-80% in 370 nS. This report discusses the design of the system controls, interlocks, power supplies, and modulator.
Date: July 1, 1997
Creator: Lamare, J de; Donaldson, A. & Kulikov, A. Lipari, J.
Partner: UNT Libraries Government Documents Department

The SLAC NLC extraction & diagnostic line

Description: A prototype extraction line for the Next Linear Collider is discussed that has several important functions that include optimizing luminosity, characterizing beam properties at the Interaction Point and transporting beams from the IP to a dump. Beam characterization includes measurements of current, position, profile, energy, polarization and low-order correlations on a bunch-to-bunch basis for feedback and stabilization. Prototype optical and diagnostic layouts are described that provide such functions. The authors also consider possibilities for e, {mu} and {gamma} secondary beam lines and dump experiments as well as energy recovery and local reuse of an assumed 10MW in each 500 GeV beam.
Date: May 1, 1995
Creator: Spencer, J.; Irwin, J.; Walz, D. & Woods, M.
Partner: UNT Libraries Government Documents Department

PLC Support Software at Jefferson Lab

Description: Several Automation Direct (DirectNet) Programmable Logic Controllers (PLCs) have been integrated into the accelerator control system at Jefferson Lab. The integration is based on new software that consists of three main parts: a PLC driver with a state machine control block, a device support module, and a common serial driver. The components of new software and experience gained with the use of this software for beam dump systems at Jefferson Lab are presented.
Date: October 1, 2002
Creator: Chevtsov, P.; Higgins, S.; Schaffner, S. & Seidman, D.
Partner: UNT Libraries Government Documents Department

Performance of the KTeV high-energy neutral kaon beam at Fermilab

Description: The performance of the primary and secondary beams for the KTeV experiments E832 and E799-II is reviewed. The beam was commissioned in the summer of 1996 and initially operated for approximately one year. The report includes results on the primary beam, target station including primary beam dump and muon sweeping system, neutral beam collimation system, and alignment.
Date: June 1, 1998
Creator: Bocean, V.
Partner: UNT Libraries Government Documents Department

Groundwater activation calculations for E872

Description: The E872 beam dump geometry has been modeled in CASIM and calculations have been done to determine the annual limits for protons n target. Results are presented using both the single resident well model (SRWM) and the newly-approved concentration model (CM). The conclusion is that the target/dump design is adequate for the maximum number of protons on target requested by the experiment, which is >1 {times} 10{sup 18} protons per year at 800 GeV.
Date: August 1, 1995
Creator: Freeman, W.S. & Collaboration, E872
Partner: UNT Libraries Government Documents Department

Design status of the NLC beam-delivery system and possible future studies

Description: The authors outline some highlights in the present design of the beam-delivery and removal system for the Next Linear Collider (NLC), and present a long list of possible or desirable future studies. On several of the listed items work has already been started since the Snowmass workshop. Other studies could be conducted, for example, in the framework of a conceptual design report (CDR).
Date: October 1, 1996
Creator: Zimmermann, F.; Bowden, G. & Burke, D.
Partner: UNT Libraries Government Documents Department

Summary of working group g: beam material interaction

Description: For the first time, the workshop on High-Intensity and High-Brightness Hadron Beams (HB2010), held at Morschach, Switzerland and organized by the Paul Scherrer Institute, included a Working group dealing with the interaction between beam and material. Due to the high power beams of existing and future facilities, this topic is already of great relevance for such machines and is expected to become even more important in the future. While more specialized workshops related to topics of radiation damage, activation or thermo-mechanical calculations, already exist, HB2010 provided the occasion to discuss the interplay of these topics, focusing on components like targets, beam dumps and collimators, whose reliability are crucial for a user facility. In addition, a broader community of people working on a variety of issues related to the operation of accelerators could be informed and their interest sparked.
Date: November 1, 2010
Creator: Kiselev, D.; /PSI, Villigen; Mokhov, N.V.; /Fermilab; Schmidt, R. & /CERN
Partner: UNT Libraries Government Documents Department

The beamline for the second axis of the dual axis radiographic hydrodynamic test facility

Description: During normal DARHT II operation, the beam exiting the accelerator will be well characterized by its nominal design parameters of 20-MeV, 2000-Amperes, 2-{micro}sec-pulse length, and 3 cm-mr unnormalized emittance. Normal operation will have the beam delivered to a beam dump via several DC magnets. A 2-way kicker magnet is used to deflect portions of the beam into the straight ahead beamline leading to either a diagnostic beamline or to the converter target beamline. During start up and or beam development periods, the beam exiting the accelerator may have parameters outside the acceptable range of values for normal operation. The Enge beamline must accommodate this range of unacceptable beam parameters, delivering the entire 80 KiloJoule of beam to the dump even though the energy, emittance, and/or match is outside the nominal design range.
Date: March 23, 1999
Creator: Caporaso, G J; Chen, Y J; Fawley, W M; Lee, E P; Paul, A C & Westenkow, G
Partner: UNT Libraries Government Documents Department

RHIC beam permit and quench detection communications system

Description: A beam permit module has been developed to concentrate RHIC, subsystem sensor outputs, permit beam, and initiate emergency shutdowns. The modules accept inputs from the vacuum, cryogenic, power supply, beam loss, and superconducting magnet quench detection systems. Modules are located at equipment locations around the RHIC ring. The modules are connected by three fiberoptic communications links; a beam permit link, and two magnet power supply interlock links. During operation, carrier presence allows beam. If a RHIC subsystem detects a fault, the beam permit carrier terminates - initiating a beam dump. If the fault was a superconducting magnet quench, a power supply interlock carrier terminates - initiating an emergency magnet power dump. In addition, the master module triggers an event to cause remote sensors to log and hold data at the time-of-failure.
Date: July 1, 1997
Creator: Conkling, C.R. Jr.
Partner: UNT Libraries Government Documents Department


Description: During the RHIC Au-run in 2001 the 200 MHz storage cavity system was used for the first time. The rebucketing procedure caused significant beam debunching in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam could account for approximately 30%-40% of the total beam intensity. Some of it will be in the abort gap. In order to minimize the risk of magnet quenching due to uncontrolled beam losses at the time of a beam dump, a combination of a fast transverse kicker and copper collimators were used to clean the abort gap. This report gives an overview of the gap cleaning procedure and the achieved performance.
Date: June 3, 2002
Partner: UNT Libraries Government Documents Department


Description: This report details the efforts by engineers at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory (BNL) to evaluate the reliability of water-cooled radiation absorbers used in the NSLS X-ray ring. These absorbers are part of the 16 dipole vacuum chambers which comprise the arc sections of the ring. They are located at the intersections (crotch) of the beamline exit ports with the electron beam chamber, and are commonly referred to as "crotches". The purpose of these efforts was to demonstrate the reliability of the crotches under operating conditions that the crotches will be subjected to over the entire expected life of the ring. The efforts described include engineering calculations, finite element analysis, conceptual design for a reliability test, test implementation and descriptions, results and conclusions related to these analyses and tests.
Date: April 9, 1999
Creator: Lynch, D. R.
Partner: UNT Libraries Government Documents Department

Plans for a 750 MeV electron beam test facility at Fermilab

Description: A 750 MeV electron beam test facility at Fermilab is in the planning and early construction phase. An existing building is being converted for this facility. The photoinjector currently in use at the Fermilab NICADD Photoinjector Laboratory (FNPL) will be moved to the new facility and upgraded to serve as an injector for a beam acceleration section consisting of three TTF or ILC-type RF cryomodules. A low energy off-axis beamline will be constructed to test ILC crab cavity designs and provide opportunities for other tests. Downstream beamlines will consist of a diagnostic section, a beam test area for additional beam experiments, and high power beam dumps. The initial program for this facility will concentrate on testing ILC-type cryomodules and RF control with full ILC beam intensity. A future building expansion will open up further possibilities for beam physics and beam technology experiments.
Date: June 1, 2007
Creator: Church, M.; Nagaitsev, S.; /Fermilab; Piot, P. & U., /Fermilab /Northern Illinois
Partner: UNT Libraries Government Documents Department

LEDA beam operations milestone and observed beam transmission characteristics

Description: Recently, the Low-Energy Demonstration Accelerator (LEDA) portion of the Accelerator Production of Tritium (APT) project reached its 100-mA, 8-hr CW beam operation milestone. LEDA consists of a 75-keV proton injector, 6.7-MeV, 350-MHz CW radio-frequency quadruple (RFQ) with associated high-power and low-level rf systems, a short high-energy beam transport (HEBT) and high-power (670-kW CW) beam dump. During the commissioning phase it was discovered that the RFQ field level needs to be approximately 5-10% higher than design in order to accelerate the full 100-mA beam with low losses. Upon further investigation, we have observed that the beam transmission for the 100-mA low-duty-factor beam is unexpectedly low for RFQ field levels between 90 and 105% of design. This paper will describe some aspects of LEDA operations critical to achieving the above milestone. Measurement and simulation results focused on understanding this reduced beam transmission for the RFQ operating at design conditions are also presented.
Date: September 1, 2000
Creator: Rybarcyk, L.
Partner: UNT Libraries Government Documents Department

BNL 703 MHz SRF cryomodule demonstration

Description: This paper will present the preliminary results of the testing of the 703 MHz SRF cryomodule designed for use in the ampere class ERL under construction at Brookhaven National Laboratory. The preliminary cavity tests, carried out at Thomas Jefferson Laboratory, demonstrated cavity performance of 20 MV/m with a Qo of 1 x 10{sup 10}, results we expect to reproduce in the horizontal configuration. This test of the entire string assembly will allow us to evaluate all of the additional cryomodule components not previously tested in the VTA and will prepare us for our next milestone test which will be delivery of electrons from our injector through the cryomodule to the beam dump. This will also be the first demonstration of an accelerating cavity designed for use in an ampere class ERL, a key development which holds great promise for future machines.
Date: May 4, 2009
Creator: Burrill,A.; Ben-Zvi, I.; Calaga, R.; Dalesio, L.; Dottavio, T.; Gassner, D. et al.
Partner: UNT Libraries Government Documents Department

Design of the ILC RTML extraction lines

Description: The ILC [1] Damping Ring to the Main Linac beamline (RTML) contains three extraction lines (EL). Each EL can be used both for an emergency abort dumping of the beam and tune-up continual train-by-train extraction. Two of the extraction lines are located downstream of the first and second stages of the RTML bunch compressor, and must accept both compressed and uncompressed beam with energy spreads of 2.5% and 0.15%, respectively. In this paper we report on an optics design that allowed minimizing the length of the extraction lines while offsetting the beam dumps from the main line by the distance required for acceptable radiation levels in the service tunnel. The proposed extraction lines can accommodate beams with different energy spreads while at the same time providing the beam size acceptable for the aluminum dump window.
Date: June 1, 2008
Creator: Seletskiy, S.; Tenenbaum, P.; Walz, D.; /SLAC; Solyak, N. & /Fermilab
Partner: UNT Libraries Government Documents Department

The ILC Beam Delivery System - Conceptual Design and RD Plans

Description: The Beam Delivery System of the ILC has many stringent and sometimes conflicting requirements. To produce luminosity, the beams must be focused to nanometer size. To provide acceptable detector backgrounds, particles far from the beam core must be collimated. Unique beam diagnostics and instrumentation are required to monitor parameters of the colliding beams such as the energy spectrum and polarization. The detector and beamline components must be protected against errant beams. After collision, the beams must also be transported to the beam dumps safely and with acceptable losses. An international team is actively working on the design of the ILC Beam Delivery System in close collaboration. Details of the design, recent progress and remaining challenges will be summarized in this paper.
Date: May 27, 2005
Creator: Seryi, Andrei
Partner: UNT Libraries Government Documents Department

A 200-A, 500-Hz, triangle current-wave modulator and magnet used for particle beam rastering

Description: This paper describes a simple 2D beam-rastering system to uniformly spread a 100-mA 6.7-MeV cw proton beam over a 50-cm by 50-cm beam stop. The basic circuit uses a 20-mF capacitor bank, a IGBT (insulated gate bipolar transistor) full-wave inverter, and a 1-mH ferrite dipole magnet to produce a {+-} 500-Gauss peak triangular-waveform deflection field at 500 Hz. A dc input voltage of 200 volts at 2.6 amps (520 watts) produces a 160-ampere peak-to-peak triangular current waveform in the ferrite magnet at 500 Hz. For dual-axis rastering, two ferrite dipoles are used, one at 500 Hz, and the other at 575 Hz, to produce a uniform 2D beam distribution at the beam stop. The paper will discuss the IGBT modulator and ferrite deflector in detail, including current and voltage waveforms, and the ferrite magnet B-dot (dB/dt) signal.
Date: October 1, 1997
Creator: Rose, C.R. & Shafer, R.E.
Partner: UNT Libraries Government Documents Department

Heat transfer and thermal stress analysis of a glass beam dump

Description: Today`s new generation lasers require durable beam dumps which can absorb large amounts of energy remaining structurally sound. This report analyzes a full scale model of one particular laser glass beam dump which tends to fail in small scale experiments. In these small scale experiments, the laser causes plasma formation on the front face of the beam dump, material spalling off of the back face, and cracking and cloudiness within the glass. This damage is more prevalent when the beam dump has been shot a number of times with the laser. While many phenomena are taking place within this beam dump, this report focuses solely on thermal effects - whether the thermal effects of laser deposition on the full-scale glass beam dump will cause failure within the glass.
Date: September 1, 1995
Creator: Garcia, V.C.
Partner: UNT Libraries Government Documents Department

Photoneutron production in electron beam stop for dual-axis radiographic hydrotest facility (DARHT)

Description: A beam stop design for an electron linear accelerator was analyzed from the perspective of photoneutron production and subsequent dose. Sophisticated nuclear data modeling codes were used to generate the photoneutron production cross sections and spectra that were then used in MCNP transport calculations. The resulting neutron dose exceeded limits for workers present in the experimental area while the accelerators are producing electron beam pulses. Therefore, the beam stop was redesigned to limit doses to acceptable values, consistent with the ALARA philosophy.
Date: March 1, 1998
Creator: Chadwick, M.B.; Brown, T.H. & Little, R.C.
Partner: UNT Libraries Government Documents Department

Design of the MI40 beam-abort dump

Description: A beam-abort dump for the Fermilab Main Injector to handle 3E13 protons per pulse at 150 Gev has been designed. A 120 GeV beam line goes through the beam-dump off-set by 27cm from its center. The design and the environmental safety aspects of the beam-dump are described here.
Date: May 1, 1995
Creator: Bhat, C.M.; Martin, P.S. & Russell, A.D.
Partner: UNT Libraries Government Documents Department

Design of an ogive-shaped beamstop

Description: This paper addresses the evolution, design, and development of a novel approach for topping cw (continuous-wave), non-rastered proton beams. Capturing the beam in vacuo within a long, axisymmetric surface of revolution has the advantages of spreading the deposited energy over a large area while minimizing prompt neutron backstreaming and reducing shield size and mass. Evolving from a cylinder/cone concept, the ogive shape avoids abrupt changes in geometry that produce sharp thermal transitions, allowing the beam energy to be deposited gracefully along its surface. Thermal management at modest temperature levels is provided with a simple, one-pass countercurrent forced-convection water passage outside the ogive. Hydrophone boiling sensors provide overtemperature protection. The concept has been demonstrated under beam conditions in the CRITS (Chalk River Injector Test Stand) facility.
Date: December 31, 1998
Creator: Hagan, T.H. van; Doll, D.W.; Schneider, J.D. & Spinos, F.R.
Partner: UNT Libraries Government Documents Department