Author: Degen, C.
Paper Title Page
MOP194 A Laser-Wire Beam-Energy and Beam-Profile Monitor at the BNL Linac 456
 
  • R. Connolly, L. DeSanto, C. Degen, R.J. Michnoff, M.G. Minty, D. Raparia
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work performed under Contract #DE-AC02-98CH10886 under the auspices of the US Department of Energy.
In 2009 a beam-energy monitor was installed in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. This device measures the energies of electrons stripped from the 40mA H beam by background gas. Electrons are stripped by the 1.7x10-7torr residual gas at a rate of ~2.4x10-8/cm. Since beam electrons have the same velocities as beam protons, the beam proton energy is deduced by multiplying the electron energy by mp/me=1836. A 183.6MeV H beam produces 100keV electrons. In 2010 we installed an optics plates containing a laser and optics to add beam-profile measurement capability via photodetachment. Our 100mJ/pulse, Q-switched laser neutralizes 70% of the beam during its 10ns pulse. The chamber in which the laser light passes through the ion beam is upstream of a dipole magnet which deflects the electrons into a biased retarding-grid (V<125kV) Faraday-cup detector. To measure beam profiles, a narrow laser beam is stepped across the ion beam removing electrons from the portion of the H beam intercepted by the laser. The laser also gives us energy measurements on the 0.2mA polarized proton beam.
 
 
WEOBN1 Simultaneous Orbit, Tune, Coupling, and Chromaticity Feedback at RHIC 1394
 
  • M.G. Minty, A.J. Curcio, W.C. Dawson, C. Degen, R.L. Hulsart, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, P. Oddo, V. Ptitsyn, G. Robert-Demolaize, T. Russo, V. Schoefer, C. Schultheiss, S. Tepikian, M. Wilinski
    BNL, Upton, Long Island, New York, USA
  • T. Satogata
    JLAB, Newport News, Virginia, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
All physics stores at the Relativistic Heavy Ion Collider are now established using simultaneous orbit, tune, coupling, and energy feedback during beam injection, acceleration to full beam energies, during the “beta-squeeze” for establishing small beam sizes at the interaction points, and during removal of separation bumps to establish collisions. In this report we describe the major changes made to enable these achievements. The proof-of-principle for additional chromaticity feedback will also be presented.
 
slides icon Slides WEOBN1 [8.054 MB]