Retarding Potential Analyzer: a versatile tool to measure effects of ion beam interactions with background gas

POSTER

Abstract

The High Current experiment (HCX) is a 1 MeV linear DC accelerator that provides a K$^{+}$ ion beam current of 180 mA for 5 $\mu $s. It constitutes an excellent platform to measure beam interaction with walls and background gas. We placed a Retarding Potential Analyzer (RPA) inside a gap between quadrupole magnets, where the beam potential of $\approx $2200V traps electrons and expels ions (from ionized gas). The trapped electrons are then expelled at the end of the pulse, when the beam potential decreases. We will show that the RPA is a versatile tool to measure particle balance and study the effects of electron accumulation.

*This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48, and by Lawrence Berkeley National Laboratory under Contract DE-AC02-05CH1123

Authors

  • Michel Kireeff Covo

    • LLNL and UCB

  • A. Molvik

  • R. Cohen

  • Alex Friedman

    • LLNL

  • J-L Vay

    • LBNL

  • F.M. Bieniosek

  • David Baca

  • P.A. Seidl

    • LBNL

  • Jasmina L. Vujic

  • Christian M. Leister

  • B.E. Rosenberg

    • UCB