Author: Ratti, A.
Paper Title Page
MOPC064 Upgrade and Commissioning of the 88-Inch Cyclotron Final Power Amplifier 229
 
  • M. Kireeff Covo, D.F. Byford, P.W. Casey, A. Hodgkinson, S. Kwiatkowski, C.M. Lyneis, L. Phair, A. Ratti, C.P. Reiter
    LBNL, Berkeley, California, USA
 
  Funding: This work was supported by the Director, Office of Science, Office of High Energy and Nuclear Physics, Division of Nuclear Physics, U.S. Department of Energy under Contract DE-AC02-05CH11231.
The RF system of the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory is a resonant system based on the quarter-wave cantilever type resonating structure. Power is fed to the Dee from the anode of the 500 kW RCA 6949 tetrode tube operating in grounded cathode configuration, which is capacitively coupled to the side of the Dee stem. The tube is obsolete and makes its continued use impractical. A new final power amplifier was designed and built using the commercially available tube Eimac 4W150,000E. The new amplifier was successfully commissioned and has been reliable and easy to operate. An overview of the system upgrade and details of the commissioning will be presented.
 
 
TUPC168 Results from the LHC BRAN Luminosity Monitor at Increased Luminosities 1428
 
  • R. Miyamoto
    BNL, Upton, Long Island, New York, USA
  • E. Bravin
    CERN, Geneva, Switzerland
  • H.S. Matis, A. Ratti, W.C. Turner, H. Yaver, T. stezelberger
    LBNL, Berkeley, California, USA
 
  Funding: This work supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The LHC BRAN luminosity monitors are used to monitor and optimize the luminosity at the LHC high luminosity interaction points IP1 and IP5. The Argon gas ionization chambers detect showers produced in the TAN absorbers by neutral particles emerging from pp collisions. The detectors have been operated during the 2010 run by counting the shower rate. As the current 2011 run has the multiplicity of proton-proton collisions per bunch crossing near ten, the detector sees more than one collision per bunch crossing. Therefore, the operation of the detector has been switched to pulse height mode to detect the average shower flux. This paper presents results from recent pulse height mode measurements, including the total and bunch-by-bunch luminosity as well as a determination of the crossing angle at these IPs. Comparisons with luminosity measurements from ATLAS and CMS are also presented.