Author: Placidi, M.
Paper Title Page
TUPFI062 Operational Results of the LHC Luminosity Monitors until LS1 1490
  • A. Ratti, S.C. Hedges, J. Jones, H.S. Matis, M. Placidi, W.C. Turner, V.K. Vytla
    LBNL, Berkeley, California, USA
  • E. Bravin, F. Roncarolo
    CERN, Geneva, Switzerland
  • R. Miyamoto
    ESS, Lund, Sweden
  Funding: Work funded by the US Department of Energy through the US- LARP program.
The monitors for the high luminosity regions in the LHC have been operating since 2009 to optimize the LHC's luminosity. The devices are gas ionization chambers inside the neutral particle absorber 140 m from the interaction point and monitor showers produced by high energy neutral particles from the collisions. They have the ability to resolve the bunch-by-bunch luminosity as well as to survive the extreme level of radiation in the nominal LHC operation. The devices have operated on a broad range of luminosity, from the initial 1028 until the levels well beyond 1033 reached in 2012. We present operational results of the device during proton and lead ion operations until LS1, which include runs at 40 MHz bunch rate and with p-Pb collisions.
WEPWA069 Design Concepts for an RF Deflecting Cavity-Based Beam Spreader for a Next Generation FEL 2274
  • M. Placidi, L.R. Doolittle, P. Emma, J.-Y. Jung, J. Qiang, A. Ratti, C. Sun
    LBNL, Berkeley, California, USA
  Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The Lawrence Berkeley National Laboratory (LBNL) is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. Electron bunches supplied by a high-brightness, high-repetition-rate photocathode electron gun are distributed by a beam spreader, designed to deliver individual bunches from a CW linac to an array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. We describe recent developments in the technical choices, design and parameters of the spreader system and its main components.