GTS meeting 12 06 16

• High voltage processing with improved gun started on November 17th
  • Improvements include:
  • Black (doped alumina) R30 insulator
  • All SS electrodes, barrel polished
  • Shed: Yan's design for <10 MV/m max field
  • NEG modules (6 WP modules on bottom of chamber). Pre-activated in gun chamber, rinsed thoroughly to minimize dust
  • Perforated plate to cover NEGs for minimizing field that can potentially lift up dust
  • We are conditioning with SS DPP dummy wafer
  • Horizontal viewports are now AR coated (both surfaces), measured at <1% reflection at 532 nm

• This is a link to the GTSLOG latest entry at 336kV in vacuum
• Mamun and Yan have made great progress with the photocathode preparation chamber'
  • The chamber has many improvements including:
  • Spring Puck retainer on top heater for adjusting the puck-efussion source gap freely,
  • ceramic insulator for biasing the puck
  • Adjustable height mask
  • Second Cs effusion source
  • Additional Thermo Couple to calibrate both heaters

• Beam line
  • The list have been assembled
  • The components are being played out on the beam line to establish length of needed spool pieces.
  • The plan is to assemble the beam line up to the second valve, this allows running beam with two slits, two viewers, three solenoids and the insertable Faraday Cup
  • ,

• Cathode solenoid magnet coil (update to follow bu Riad)

• Kevin Jordan is studying the damaged YAG beam line viewer crystals, pictures to follow