GTS meeting 12 06 16

• High voltage processing with improved gun started on November 17th
  • Improvements include:

1. 1. Black (doped alumina) R30 insulator
   2. All SS electrodes, barrel polished
   3. Shed: Yan's design for <10 MV/m max field
   4. NEG modules (6 WP modules on bottom of chamber). Pre-activated in gun chamber, rinsed thoroughly to minimize dust
   5. Perforated plate to cover NEGs for minimizing field that can potentially lift up dust
   6. We are conditioning with SS DPP dummy wafer
   7. 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