Author: Schippers, J.M.
Paper Title Page
TU3PB04 TRIUMF Extraction Foil Developments and Contamination Reduction 269
  • Y.-N. Rao, R.A. Baartman, I.V. Bylinskii, V.A. Verzilov
    TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
  • J.M. Schippers
    PSI, Villigen PSI, Switzerland
  Funding: TRIUMF receives funding via a contribution agreement through the National Research Council of Canada.
We made important developments on the extraction probes and stripping foils at TRIUMF. One of the issues we had was the 7Be contamination being observed near the 1A stripper, and relatedly, stripping foils warped or even broke during use. This was deemed due to over-heating in the foil and the frame. Another issue was related to the beam spills. Beam spills are primarily caused by the large angle scattering from the stripping foil. It was thus suggested that thinner foils be used to minimize the scattering. In view of these 2 issues, improvements were made such that (1) highly-orientated pyrolytic graphite foils, of thickness around 2 mg/cm2, are now used; (2) Tantalum frame is now used in place of the previous stainless steel. These changes, plus additional heat relief features introduced, have resulted in 4 times longer lifetime with the foil, and 5 to 10 times reduction to the tank contamination level around the extraction probe. Also, these improvements have led to significantly reduced amount of beam spill monitor trips. This paper presents these developments and outcomes, including the simulations and calculations performed.
slides icon Slides TU3PB04 [4.798 MB]