Author: Rosas, P.J.
Paper Title Page
TUP253 AGS Tune Jump Power Supply Design and Test 1298
 
  • J.-L. Mi, J.W. Glenn, H. Huang, I. Marneris, P.J. Rosas, J. Sandberg, Y. Tan, W. Zhang
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A horizontal tune jump system has been installed to overcome the horizontal intrinsic spin resonances, which requires jumping the horizontal tune 0.04 units 82 times, 41 up and 41 down. Two quadruple magnets have been installed in AGS ring to do this. The pulsed magnet currents range from about 140 amps near injection to about 1400 amps late. Current pulse rise and fall times are around 100 micro-sec and flat tops time are around 4mS. These quadruples have separate supplies. This tune jump pulse power supply employees all semiconductor parts as the main switches. During dummy load and magnet testing, the test result showed that the power supply could meet the specification. This article will describe some detail of power supply simulation, design and testing. Some test waveform and pictures are presented in this paper.
 
 
TUP284 AGS Tune Jump System to Cross Horizontal Depolarization Resonances Overview 1361
 
  • J.W. Glenn, L. A. Ahrens, Z. Altinbas, W. Fu, J.-L. Mi, P.J. Rosas, V. Schoefer, C. Theisen
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Two partial snakes overcome the vertical depolarizing resonances in the AGS. But a new type of depolarizing intrinsic resonance from horizontal motion appeared. We reduce these using horizontal tune jumps timed to these resonances. We gain a factor of five in crossing rate with a tune jump of 0.04 in 100 micro-sec. Two quadrapoles, we described in 2009 *, pulse 42 times, the current matching beam energy. The power supplies for these quads will be described in this conference**. The controls for the Jump Quad system is based on a BNL designed Quad Function Generator. Two modules are used; one for timing, and one to supply reference voltages. Synchronization is provided by a proprietary serial bus, the Event Link. The AgsTuneJump application predicts the times of the resonances during the AGS cycle and calculates the power supply trigger times from externally collected tune and energy verses time data and the Low and High PS voltage functions from a voltage to current model of the power supply. The system was commissioned during runs 09 & 10. Beam effects are described elsewhere in this conference***. Details of improvements, operation and the feed forward software will be described.
* JW Glenn, et al “AGS Fast Spin Resonance,-” PAC-09
** JL Mi, et al “AGS Tune Jump Power-” these proceedings
*** L.A.Ahrens, et al "Recent RHIC Motivated Polarized-" these proceedings