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Quadrupole Beam-Based Alignment in the RHIC Interaction Regions

Description: Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements.
Date: March 1, 2011
Creator: Satogata, T.
Partner: UNT Libraries Government Documents Department

Quadrupole beam-based alignment in the RHIC interaction regions

Description: Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements. BBA data has been collected over the past two runs for all three of the active experimental IRs at RHIC, updating results from the 2005 run which were taken with incorrectly installed offsets. The technique was successfully applied to expose a systematic misuse of the BPM survey offsets in the control system. This is likely to benefit polarized proton operations as polarization transmission through acceleration ramps depends on RMS orbit control in the arcs, but a quantitative understanding of its impact is still under active investigation. Data taking is ongoing as are refinements to the BBA technique aimed at reducing systematic errors and properly accounting for dispersive effects. Further development may focus on non-triplet BPMs such as those located near snakes, or arc quadrupoles that do not have individually shunted power supplies (a prerequisite for the current method) and as such, will require a modified procedure.
Date: March 28, 2011
Creator: Ziegler, J. & Satogata, T.
Partner: UNT Libraries Government Documents Department

RHIC RF Harmonic Numbers for Low Energy Operations

Description: There have been several test runs of RHIC operations to explore the feasibility of luminosity production at low energies. There is considerable international interest in the possible existence of a QCD phase diagram critical point in the RHIC gold-gold collision energy range of {radical}s{sub NN} = 5-50 GeV[l, 2, 3]. This paper reviews the RF harmonic number constraints for RHIC gold-gold collisions in this energy range, and concludes that optimal simultaneous collisions at both experiments are only feasible when the harmonic number is divisible by 9.
Date: May 1, 2008
Creator: Satogata,T.
Partner: UNT Libraries Government Documents Department

RHIC local orbit control and power supply resolution

Description: Slow global orbit correction at store, running every 30-60 minutes, has been in place since RHIC Run-8. This correction should include tight orbit drift tolerances at the interaction point and collimators, as these are locations where orbit drift of a few hundred microns is observable in backgrounds and luminosity. Future improvements in low beta optics will only lower these tolerances. runfy09 attempts to control the collimator orbit with local three-bumps after global orbit corrections appeared to be limited by corrector power supply resolution. This paper evaluates orbit control in the context of existing corrector power supply resolution, and makes recommendations for planned RHIC operations scenarios.
Date: December 1, 2009
Creator: Satogata, T.
Partner: UNT Libraries Government Documents Department

RHIC low energy beam loss projections

Description: For RHIC low-energy operations, we plan to collide Au beams with energies of E = 2:5-10 GeV/u in RHIC. Beams are injected into collision optics, and RHIC runs as a storage ring with no acceleration. At these low energies, observed beam lifetimes are minutes, with measured beam lifetimes of 3.5 min (fast) and 50 min (slow) at E=4.6 GeV/u in the March 2008 test run. With these lifetimes we can operate RHIC as a storage ring to produce reasonable integrated luminosity. This note estimates beam losses and collimator/dump energy deposition in normal injection modes of low energy operation. The main question is whether a normal injection run is feasible for an FY10 10-15 week operations run from a radiation safety perspective. A peripheral question is whether continuous injection operations is feasible from a radiation safety perspective. In continuous injection mode, we fill both rings, then continuously extract and reinject the oldest bunches that have suffered the most beam loss to increase the overall integrated luminosity. We expect to gain a factor of 2-3 in integrated luminosity from continuous injection at lowest energies if implemented[1]. Continuous injection is feasible by FY11 from an engineering perspective given enough effort, but the required extra safety controls and hardware dose risk make it unappealing for the projected luminosity improvement. Low-energy electron cooling will reduce beam losses by at least an order of magnitude vs normal low-energy operations, but low energy cooling is only feasible in the FY13 timescale and therefore beyond the scope of this note. For normal injection low energy estimates we assume the following: (1) RHIC beam total energies are E=2.5-10 GeV/u. (Continuous injection mode is probably unnecessary above total energies of E=7-8 GeV/u.); (2) RHIC operates only as a storage ring, with no acceleration; (3) 110 bunches of about 0.5-1.0 x ...
Date: August 1, 2009
Creator: Satogata,T.
Partner: UNT Libraries Government Documents Department

The RHIC transfer line cable database

Description: A cable database was created to facilitate and document installation of cables and wiring in the RHIC project, as well as to provide a data source to track possible wiring and signal problems. The eight tables of this relational database, currently implemented in Sybase, contain information ranging from cable routing to attenuation of individual wires. This database was created in a hierarchical scheme under the assumption that cables contain wires -- each instance of a cable has one to many wires associated with it. This scheme allows entry of information pertinent to individual wires while only requiring single entries for each cable. Relationships to other RHIC databases are also discussed.
Date: May 1, 1995
Creator: Scholl, E.H. & Satogata, T.
Partner: UNT Libraries Government Documents Department

Modulational effects in accelerators

Description: We discuss effects of field modulations in accelerators, specifically those that can be used for operational beam diagnostics and beam halo control. In transverse beam dynamics, combined effects of nonlinear resonances and tune modulations influence diffusion rates with applied tune modulation has been demonstrated. In the longitudinal domain, applied RF phase and voltage modulations provide mechanisms for parasitic halo transport, useful in slow crystal extraction. Experimental experiences with transverse tune and RF modulations are also discussed.
Date: December 1, 1997
Creator: Satogata, T.
Partner: UNT Libraries Government Documents Department

HADRON BEAM-BEAM DIFFUSION IN 2.5-D*.

Description: The standard analysis of modulational diffusion for general nonlinearities is qualitatively summarized, and compared to the particular case of a beam-beam simulation with two kicks per turn, plus tune modulation. A simulation with realistic Tevatron parameters shows amplitude growth over long timescales of order 10{sup 4} synchrotrons periods. The simulated amplitude growth is qualitatively similar to the predictions of modulational diffusion, showing large discrete steps in the evolution speed as the tune distance from the nearest 2-D weak coupling resonance is varied. However, the simulation shows a fundamental difference is that the observed amplitude growth is approximately exponential in time, and not approximately root time as predicted in the standard analysis. Possible reasons for this and other discrepancies are briefly discussed.
Date: April 12, 1999
Creator: SATOGATA,T.
Partner: UNT Libraries Government Documents Department

A Survey of Hadron Therapy Accelerator Technologies.

Description: Hadron therapy has entered a new age [1]. The number of facilities grows steadily, and 'consumer' interest is high. Some groups are working on new accelerator technology, while others optimize existing designs by reducing capital and operating costs, and improving performance. This paper surveys the current requirements and directions in accelerator technology for hadron therapy.
Date: June 25, 2007
Creator: PEGGS,S.; SATOGATA, T. & FLANZ, J.
Partner: UNT Libraries Government Documents Department

BEAM-BASED SEXTUPOLE POLARITY VERIFICATION IN THE RHIC

Description: This article presents a beam-based method to check RHIC arc sextupole polarities using local horizontal orbit three-bumps at injection energy. We use 11 bumps in each arc, each covering two SFs (focusing sextupoles) and one SD (defocusing sextupole). If there are no wrong sextupole polarities, the tune shifts from bump to bump and the tune shift patterns from arc to arc should be similar. Wrong sextupole polarities can be easily identified from mismatched signs or amplitudes of tune shifts from bump to bump and/or from arc to arc. Tune shifts in both planes during this study were tracked with a high-resolution base-band tunemeter (BBQ) system. This method was successfully used to the sextupole polarity check in RHIC Blue and Yellow rings in the RHIC 2006 and 2007 runs.
Date: June 25, 2007
Creator: LUO,Y.; SATOGATA, T.; CAMERON, P.; DELLAPENNA, A. & TRBOJEVIC, D.
Partner: UNT Libraries Government Documents Department

The correction of linear lattice gradient errors using an AC dipole

Description: Precise measurement of optics from coherent betatron oscillations driven by ac dipoles have been demonstrated at RHIC and the Tevatron. For RHIC, the observed rms beta-beat is about 10%. Reduction of beta-beating is an essential component of performance optimization at high energy colliders. A scheme of optics correction was developed and tested in the RHIC 2008 run, using ac dipole optics for measurement and a few adjustable trim quadruples for correction. In this scheme, we first calculate the phase response matrix from the. measured phase advance, and then apply singular value decomposition (SVD) algorithm to the phase response matrix to find correction quadruple strengths. We present both simulation and some preliminary experimental results of this correction.
Date: May 4, 2009
Creator: Wang,G.; Bai, M.; Litvinenko, V.N. & Satogata, T.
Partner: UNT Libraries Government Documents Department

REMOTE OPERATIONS IN A GLOBAL ACCELERATOR NETWORK.

Description: The INTRODUCTION to this paper summarizes the history of the Global Accelerator Network (GAN) concept and the recent workshops that discussed the relationship between GAN and Remote Operations. The REMOTE OPERATIONS SCENARIOS section brings out the organizational philosophy embodied in GAN-like and to non-GAN-like scenarios. The set of major TOPICS RAISED AT THE WORKSHOPS are only partially resolved. COLLABORATION TOOLS are described and discussed, followed by examples of REMOTE ACCELERATOR CONTROL PROJECTS around the world.
Date: May 12, 2003
Creator: PEGGS,S.; SATOGATA,T.; AGARWAL,D. & RICE,D.
Partner: UNT Libraries Government Documents Department

Hadron beam-beam diffusion in 2.5-D

Description: The standard analysis of modulational diffusion for general nonlinearities is qualitatively summarized, and compared to the particular case of a beam-beam simulation with two kicks per turn, plus tune modulation. A simulation with realistic Tevatron parameters shows amplitude growth over long timescales of order 10{sup 4} synchrotron periods. The simulated amplitude growth is qualitatively similar to the predictions of modulational diffusion, showing large discrete steps in the evolution speed as the tune distance from the nearest 2-D weak coupling resonance is varied. However, the simulation shows a fundamental difference in that the observed amplitude growth is approximately exponential in time, and not approximately root time as predicted in the standard analysis. Possible reasons for this and other discrepancies are briefly discussed.
Date: July 1, 1999
Creator: Satogata, T. & Peggs, S.
Partner: UNT Libraries Government Documents Department

OPERATIONS ELECTRONIC LOGBOOK EXPERIENCE AT BNL.

Description: A web-based system for electronic logbooks, ''elog'', developed at Fermilab (FNAL), has been adopted for use by AGS and RHIC operations and physicists at BNL for the 2001-2 fixed target and collider runs. This paper describes the main functional and technical issues encountered in the first year of electronic logbook use, including security, search and indexing, sequencer integration, archival, and graphics management. We also comment on organizational experience and planned changes for the next facility run starting in September 2002.
Date: June 2, 2002
Creator: SATOGATA,T.; CAMPBELL,I.; MARR,G. & SAMPSON,P.
Partner: UNT Libraries Government Documents Department

Accelerator physics analysis with an integrated toolkit

Description: Work is in progress on an integrated software toolkit for linear and nonlinear accelerator design, analysis, and simulation. As a first application, beamline'' and MXYZPTLK'' (differential algebra) class libraries, were used with an X Windows graphics library to build an user-friendly, interactive phase space tracker which, additionally, finds periodic orbits. This program was used to analyse a theoretical lattice which contains octupoles and decapoles to find the 20th order, stable and unstable periodic orbits and to explore the local phase space structure.
Date: August 1, 1992
Creator: Holt, J.A.; Michelotti, L. & Satogata, T.
Partner: UNT Libraries Government Documents Department