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Heavy Flavor Measurements at RHIC in the Near Future

Description: We discuss the recent results on open charm measurements at RHIC. The heavy flavor upgrade program for both PHENIX and STAR experiments are briefly discussed. The completion of the program will yield important information on light flavor thermalization of the partonic matter created in high-energy nuclear collisions at RHIC. A new era of RHIC is ahead of us with the progress of the upgrade program.
Date: December 1, 2006
Creator: Xu, Nu
Partner: UNT Libraries Government Documents Department

LINEAR OPTICS DURING THE RHIC 2001 - 2 RUN.

Description: The RHIC 2001-2 Au and polarized proton runs used several different low-beta optics configurations. Low-beta squeezes were routinely performed through the Au acceleration ramp to optimize injection and transition optics; the polarized proton run injected and accelerated with constant low-beta optics to optimize polarization preservation. This paper summarizes tools, methods and results for linear optics measurement and correction during these runs as well as future plans.
Date: June 2, 2002
Creator: SATOGATA,T.; CARDONA,J.; PTITSYN,V.; TEPIKIAN,S. & VAN ZEIJTS,J.
Partner: UNT Libraries Government Documents Department

SNAKE CALIBRATION IN RHIC.

Description: A proper understanding of the response of the spin orientation due to the currents in the four helices which make up each snake is necessary to control spin tune, avoid snake resonances and facilitate the operation of the RHIC spin flipper. The effect of the helical dipole snakes in RHIC is to rotate the spin orientation an angle {mu} about an axis at an angle {phi} in the horizontal plane. With two snakes the combined effect gives rise to a spin precession frequency which is determined by the {mu} and {phi} angles at each snake. Depolarization or spin flipping can occur when this spin tune is near an external driving frequency. We employed the RHIC spin flipper in this way to determine the spin tune and thus verify spin tune predictions based upon previous field measurements of the snake. We also considered the response of snake resonances locations to spin tune as another way of verifying spin tune predictions.
Date: June 2, 2002
Creator: RANJBAR,V.; BAI,M.; LUCCIO,A.; MACKAY,W.W.; ROSER,T. & LEET,S.Y.
Partner: UNT Libraries Government Documents Department

Rf systems for RHIC

Description: The RHIC rf systems must capture the injected beam, accelerate it through transition to top energy, shorten the bunches prior to rebucketing, and store the beam for 10 hours in the presence of strong intra-beam scattering. These different functions are met by three independent systems. An accelerating system at 26.7 Mhz (h = 342), a storage system at 196.1 MHz (h = 2508), and a wideband system for the damping of injection efforts.
Date: May 1, 1995
Creator: Rose, J.; Brodowski, J.; Connolly, R.; Deng, D.P.; Kwiatkowski, S.; Pirkl, W. et al.
Partner: UNT Libraries Government Documents Department

A STATE VARIABLE DESCRIPTION OF THE RHIC RF CONTROL LOOPS.

Description: The beam transfer function changes during the RHIC ramp. The response of the RF control loops changes as a result. A state-variable description of the beam and the RF control loops was developed. This description was used to generate a set of feedback matrices that keeps the response of the RF control loops constant during the ramp. This paper describes the state-variable description and its use in determining the K matrices.
Date: June 2, 2002
Creator: SCHULTHEISS,C. & BRENNAN,J.M.
Partner: UNT Libraries Government Documents Department

REAL TIME BETATRON TUNE CONTROL IN RHIC.

Description: Precise control of the betatron tunes is necessary to preserve proton polarization during the RHIC ramp. In addition, control of the tunes during beam deceleration is necessary due to hysteresis in the superconducting magnets. A real-time feedback system to control the betatron tunes during ramping has been developed for use in RHIC. This paper describes this system and presents the results from commissioning the system during the polarized proton run.
Date: June 2, 2002
Creator: SCHULTHEISS,C.; CAMERON,P.; MARUSIC,A. & VAN ZEIJTS,J.
Partner: UNT Libraries Government Documents Department

RHIC ABORT KICKER WITH REDUCED COUPLING IMPEDANCE.

Description: Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.
Date: June 2, 2002
Creator: HAHN,H. & DAVINO,D.
Partner: UNT Libraries Government Documents Department

ACCELERATING AND COLLIDING POLARIZED PROTONS IN RHIC WITH SIBERIAN SNAKES.

Description: We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV. We report on our experiences during commissioning and operation of collider with polarized protons.
Date: June 2, 2002
Creator: ROSER,T.; AHRENS,L.; ALESSI,J.; BAI,M.; BEEBE - WANG,J.; BRENNAN,J.M. et al.
Partner: UNT Libraries Government Documents Department

MEASUREMENTS OF MECHANICAL TRIPLET VIBRATIONS IN RHIC.

Description: Mechanical vibrations of the RHIC interaction region triplets has been identified as the dominant source of orbit jitter for frequencies up to 20 Hz. We report the results of detailed measurements that were performed to characterize these effects. We discuss the impact on beam dynamics and possible cures.
Date: June 2, 2002
Creator: MONTAG,C.; BRENNAN,M.; BUTLER,J.; BONATI,R. & KOELLO,P.
Partner: UNT Libraries Government Documents Department

RHIC BPM SYSTEM PERFORMANCE, UPGRADES, AND TOOLS.

Description: During the RHIC 2001-2 run, the beam position monitor (BPM) system provided independent average orbit and turn-by-turn (TBT) position measurements at 162 locations in each measurement plane and RHIC ring. TBT acquisition was successfully upgraded from 128 turns to 1024 turns per trigger, including injection. Closed orbits were acquired and automatically archived every two seconds through each acceleration ramp for orbit analysis and feed-forward orbit correction. This paper presents the overall system performance during this run, including precision, reproducibility, radiation damage, and analysis tools. We also summarize future plans, including million-turn TBT acquisition for nonlinear dynamics studies.
Date: June 2, 2002
Creator: SATOGATA,T.; CAMERON,P.; CERNIGLIA,P.; CUPOLO,J.; DAWSON,C.; DEGEN,C. et al.
Partner: UNT Libraries Government Documents Department

TRANSVERSE IMPEDANCE MEASUREMENT AT THE RHIC.

Description: The RHIC transverse impedance was measured during the last operation run. Measurement of the imaginary part of the broadband impedance was the main goal. No large difference between the two rings was found nor in either plane. The measured tune shift is larger than the expected by a factor of 2.5 to 3. Several other issues such as the real part impedance measurement are also presented.
Date: June 2, 2002
Creator: ZHANG,S.Y.; HUANG,H.; CAMERON,P.; DREES,A.; FLILLER,R. & SATOGATA,T.
Partner: UNT Libraries Government Documents Department

ACTION AND PHASE ANALYSIS TO DETERMINE SEXTUPOLE ERRORS IN RHIC AND THE SPS.

Description: Success in the application of the action and phase analysis to find linear errors at RHIC Interaction Regions [1] has encouraged the creation of a technique based on the action and phase analysis to find non linear errors. In this paper we show the first attempt to measure the sextupole components at RHIC interaction regions using the action and phase method. Experiments done by intentionally activating sextupoles in RHIC and in SPS [2] will also be analyzed with this method. First results have given values for the sextupole errors that at least have the same order of magnitude as the values found by an alternate technique during the RHIC 2001 run [3].
Date: May 12, 2003
Creator: Cardona, J.; Peggs, S.; Satogata, T. & Tomas, R.
Partner: UNT Libraries Government Documents Department

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 presented and compared. Upgrades of the system for the upcoming high luminosity runs are outlined.
Date: May 19, 2003
Creator: DREES,K. A. FLILLER,R. TRBOJEVIC,D. KAIN,V.
Partner: UNT Libraries Government Documents Department

RHIC PC CNI POLARIMETER:STATUS AND PERFORMANCE FROM THE FIRST COLLIDER RUN.

Description: Polarimeters using the proton carbon elastic scattering process in Coulomb Nuclear Interference (CNI) region were installed in two RHIC rings. Polarization measurements were successfully carried out with the high energy polarized proton beams for the first polarized pp collision run. The physics principles, performance, and polarization measurements are presented.
Date: September 9, 2002
Creator: Jinnouchi, O; Bland, L C; Bravar, A; Bunce, G; Cadman, R; Deshpande, A D et al.
Partner: UNT Libraries Government Documents Department