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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.
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Partner: UNT Libraries Government Documents Department
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A METHOD TO MEASURE THE FOCUSING PROPERTIES (R-MATRIX) OF A MAGNET.

Description: In this paper we discuss, and study the feasibility of a method that may be used to measure the focusing properties of a magnet. This method may prove valuable when applied to ''non-conventional'' magnets that deviate from the usual dipole magnets or other multipole magnets (quadrupoles/sextupoles etc.) which are commonly used in a synchrotron or a beam line. In this category of ''non-conventional'' magnets, fall special magnets, which come under the name ''Snakes'', which are being used in syn… more
Date: July 5, 2004
Creator: TSOUPAS,N. THIEBERGER,P. BROWN,K. GASSNER,D. GLENN,W. AHRENS,L. ROSER,T. LEE,Y. Y. WEI,J.
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Partner: UNT Libraries Government Documents Department
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A split-electrode for clearing scattered electrons in the RHIC e-lens

Description: We are designing two electron lenses that will be installed at RHIC IR10 to compensate for the head-on beam-beam effect. To clear accumulated scattered electrons from 100 GeV proton-electron head-on collisions in the e-lens, a clearing split electrode may be constructed. The feasibility of this proposed electrode was demonstrated via the CST Particle Studio and Opera program simulations. By splitting one of the drift tubes in the e-lens and applying {approx} 380 V across the two parts, the scat… more
Date: May 20, 2012
Creator: X., Gu; Pikin, A.; Thieberger, P.; Fischer, W.; Hock, J.; Hamdi, K. et al.
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Partner: UNT Libraries Government Documents Department
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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.
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Partner: UNT Libraries Government Documents Department
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CRYSTAL COLLIMATION AT RHIC.

Description: Crystal Channeling occurs when an ion enters a crystal with a small angle with respect to the crystal planes. The electrostatic interaction between the incoming ion and the lattice causes the ion to follow the crystal planes. By mechanically bending a crystal, it is possible to use a crystal to deflect ions. One novel use of a bent crystal is to use it to channel beam halo particles into a collimator downstream. By deflecting the halo particles into a collimator with a crystal it may be possibl… more
Date: June 19, 2003
Creator: FLILLER,R. P.,III. DREES,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
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R&D ERL: Diagnostics

Description: The Energy Recovery Linac (ERL) prototype project is currently under development at the Brookhaven National Laboratory. The ERL is expected to demonstrate energy recovery of high intensity beams with a current of up to a few hundred milliamps, while preserving the emittance of bunches with a charge of a few nanocoulombs produced by a high current SRF gun. To successfully accomplish this task the machine will include beam diagnostics that will be used for accurate characterization of the three d… more
Date: January 1, 2010
Creator: Gassner, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ELECTRON DETECTORS FOR VACUUM PRESSURE RISE DIAGNOSTICS AT RHIC.

Description: In the RHIC 2001 run, an unexpected vacuum pressure rise versus bunch increasing currents was observed in both gold and proton operations. This pressure increase due to molecular desorption is suspected to be induced mainly by electron multipacting, but other causes may coexist, such as ion desorption due to halo scraping. In order to get a reliable diagnostic of the phenomenon electron detectors have been installed along the RHIC ring. In this report we describe results measured by the electro… more
Date: May 12, 2003
Creator: IRISO-ARIZ,U. DREES,A. FISCHER,W. GASSNER,D. GOULD,O. GULLOTTA,J. LEE,R. PONNAIYAN,V. TRBOJEVIC,D. ZENO,K. ZHANG,S. Y.
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Partner: UNT Libraries Government Documents Department
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Preliminary Design of the Beam Loss Monitoring System for the SNS

Description: The SNS to be built at Oak Ridge National Laboratory will provide a high average intensity 1 GeV beam to produce spallation neutrons. Loss of a even small percentage of this intense beam would result in high radiation. The Beam Loss Monitor (ELM) system must detect such small, long term losses yet be capable of measuring infrequent short high losses. The large dynamic range presents special problems for the system design. Ion chambers will be used as the detectors. A detector originally designe… more
Date: May 6, 2002
Creator: Witkover, R. & Gassner, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Closing plenary summary of working group 4 instrumentation and controls for ERL2011

Description: Working group 4 was charged with presentations and discussions on instrumentation and controls with regards to Energy Recovery Linacs (ERL). There were 4 sessions spanning 3.5 hours in which 7 talks were delivered, the first being an invited plenary presentation. The time allotted for each talk was limited to 20-25 minutes in order to allow 5-10 minutes for discussion. Most of the talks were held in joint session with working group 5 (Unwanted Beam Loss). This format was effective for the purpo… more
Date: October 16, 2011
Creator: Gassner, D. & Obina, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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DESIGN OF AN IMPROVED ION CHAMBER FOR THE SNS.

Description: Ion chambers are in common use as beam loss monitors at many accelerators. A unit designed and used at FNAL and later at BNL was proposed for the SNS. Concerns about the ion collection times and low collection efficiency at high loss rates led to improvements to this unit and the design of an alternate chamber with better characteristics. Prototypes have been tested with pulsed beams. The design and test results for both detectors will be presented.
Date: May 6, 2002
Creator: Witkover, R. L. & Gassner, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Crystalline Chromium Doped Aluminum Oxide (Ruby) Use as a Luminescent Screen for Proton Beams.

Description: In our search for a better luminescent screen material, we tested pieces of mono-crystalline chromium doped aluminum oxide (more commonly known as a ruby) using a 24 GeV proton beam. Due to the large variations in beam intensity and species which are run at the Alternating Gradient Synchrotron (AGS), we hope to find a material which can sufficiently luminesce, is compatible in vacuum, and maintain its performance level over extended use. Results from frame grabbed video camera images using a va… more
Date: March 29, 1999
Creator: Brown, K. A. & Gassner, D. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Using an IIDC/DCAM camera for beam display and analysis

Description: An IIDC/DCAM camera is used to the RHIC beams as they pass through a hydrogen jet. The data is transferred over a 1394 bus to a computer with a Linux operating system. A software process on that computer collects the individual frames and packages them into parameters within the RHIC control system's framework. This information is packaged to continuously update two primary types of clients: One type is responsible for near-real-time display of the images; useful in comfort displays, etc. The s… more
Date: October 12, 2009
Creator: Olsen,R.H.; Gassner, D. & Hoff, L. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Data Acquisition for Sns Beam Loss Monitor System

Description: The Spallation Neutron Source (SNS) beam loss monitor system uses VME based electronics to measure the radiation produced by lost beam. Beam loss signals from cylindrical argon-filled ion chambers and neutron detectors will be conditioned in analog front-end (AFE) circuitry. These signals will be digitized and further processed in a dedicated VME crate. Fast beam inhibit and low-level, long-term loss warnings will be generated to provide machine protection. The fast loss data will have a bandwi… more
Date: October 13, 2003
Creator: Yeng, Y.; Gassner, D.; Hoff, L. & Witkover, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A scanning target profile monitor for the slow extracted beam at the AGS

Description: The purpose of this new instrument is for probing beam halo and obtaining beam profiles of the resonant extracted beam at the AGS. The device described here is a prototype version, to obtain data and prepare for a more permanent device. The goals of the permanent device are to allow emittances of low current, but high intensity slowly extracted beams to be accurately measured and to have a diagnostic for probing the wings of the beam distribution. The device works on secondary emission from thi… more
Date: July 1, 1997
Creator: Brown, K. A.; Chiang, I. H. & Gassner, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Baseline suppression problems for high precision measurements using optical beam profile monitors

Description: The use of fluorescent screens (e.g. YAG screens) and Optical Transition Radiation (OTR) screens for beam profile monitors provides a simple and widely used way to obtain detailed two dimensional intensity maps. What makes this possible is the availability of relatively inexpensive CCD cameras. For high precision measurements many possible error contributions need to be considered that have to do with properties of the fluorescent screens and of the CCDs. Saturation effects, reflections within … more
Date: March 28, 2011
Creator: Thieberger, P.; Gassner, D.; Glenn, J.; Minty, M. & Zimmer, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Optimizing the beam-beam alignment in an electron lens using bremsstrahlung

Description: Installation of electron lenses for the purpose of head-on beam-beam compensation is foreseen at RHIC. To optimize the relative alignment of the electron lens beam with the circulating proton (or ion) beam, photon detectors will be installed to measure the bremsstrahlung generated by momentum transfer from protons to electrons. We present the detector layout and simulations of the bremsstrahlung signal as function of beam offset and crossing angle.
Date: May 23, 2010
Creator: Montag, C.; Fischer, W.; Gassner, D.; Thieberger, P. & Haug, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ELECTRON BEAM ION SOURCE PREINJECTOR PROJECT (EBIS) CONCEPTUAL DESIGN REPORT.

Description: This report describes a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC) based on a high charge state Electron Beam Ion Source (EBIS), a Radio Frequency Quadrupole (RFQ) accelerator, and a short Linac. The highly successful development of an EBIS at BNL now makes it possible to replace the present pre-injector that is based on an electrostatic Tandem with a reliable, low maintenance Linac-based pre-injector. Linac-based pre-injectors are presently used at most accelerat… more
Date: February 28, 2005
Creator: ALESSI, J.; BARTON, D.; BEEBE, E.; GASSNER, D. & AL., ET
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Quick setup of unit test for accelerator controls system

Description: Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first i… more
Date: March 28, 2011
Creator: Fu, W.; D'Ottavio, T.; Gassner, D.; Nemesure, S. & Morris, J.
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Partner: UNT Libraries Government Documents Department
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