Conference Paper

RHIC BPM system modifications and performance

Brookhaven National Laboratory, Upton, NY 11973– 5000, USA, email
DOI: 10.1109/PAC.2005.1590995 Conference: Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the
Source: IEEE Xplore


The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gainswitching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region beam-based alignment efforts. We also summarize performance of recently-added DSP profile scan capability, and improved million-turn TBT acquisition channels for 10 Hz triplet vibration, nonlinear dynamics, and echo studies.

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Available from: Peter Cameron, Apr 29, 2015
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    • "RIDe BPM SYSTEM OVERVIEW The Relativistic Heavy Ion Collider (RHIC) BPM system [1][2] "
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    ABSTRACT: RHIC beam position monitor (BPM) system average orbit was originally calculated by averaging positions of 10000 consecutive turns for a single selected bunch. Known perturbations in RHIC particle trajectories, with multiple frequencies around 10 Hz, contribute to observed average orbit fluctuations. In 2006, the number of turns for average orbit calculations was made programmable; this was used to explore averaging over single periods near 10 Hz. Although this has provided an average orbit signal quality improvement, an average over many periods would further improve the accuracy of the measured closed orbit. A new continuous average orbit calculation was developed just prior to the 2009 RHIC run and was made operational in March 2009. This paper discusses the new algorithm and performance with beam.
    Full-text · Article · Jan 2009
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    • "Operational experience at RHIC has also demonstrated that BPM readings can have large digital offsets, and these offsets can vary over time due to issues with aging gain and calibration relays [5]. BPMs in the 6-and 8-o'clock low+ IRs were modified to remove these relays during the 2004 shutdown period. "
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    ABSTRACT: Successful implementation of a beam-based alignment algorithm, tailored to different types of quadrupoles at RHIC, provides significant benefits to machine operations for heavy ions and polarized protons. This algorithm was used to calibrate beam position monitor centers relative to interaction region quadrupoles to maximize aperture. This approach was also used to determine the optimal orbit through transition jump quadrupoles to minimize orbit changes during the transition jump for heavy ion acceleration. This paper provides background discussion and results from first measurements during the RHIC 2005 run.
    Full-text · Conference Paper · May 2005
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    ABSTRACT: We apply the independent component analysis (ICA) algorithm to uncover intrinsic noise in the beam position monitor (BPM) system. Numerical simulations found that ICA is efficient in the BPM noise estimation. The ICA algorithm is applied to the turn-by-turn data at the Relativistic Heavy Ion Collider. We found the distribution of the BPM noise level, which is consistent with the Johnson-Nyquist thermal noise model. The ICA analysis of turn-by-turn data can be used in neuronetwork feasibility of monitoring a storage ring parasitically.
    No preview · Article · Jan 2015 · Physical Review Special Topics - Accelerators and Beams