Robust Meeting - August 7, 2020

Meeting Info

• Time : August 7, 2-3 pm
• Bluejeans : https://bluejeans.com/7572697097

Action Items

Joe - coordinate a kick-off meeting with Cornell group

Riad - start discussion with Bryan Moffit, develop work plan and purchasing list to build ad commission polarimeter DAQ in the Oct 20 - Mar 21

• Jul-Aug 2008 keV CEBAF Mott (100/500) last time
• (2) detectors installed @ 120 deg + other (2) Riad's office; many pairs of pre-amps stored in office
• Riad suggests 200 keV (low risk for gun, less x-ray background, lower cross-section) ideally @ 130 deg
• Riad is building a Mott DAQ at UITF
  • 19" rack (Scott is going to buy, goes on top of cave)
  • VME crate => buying new crate (Chris Cuevas will buy) + SBC (single board computer) brain of crate (ordered)
  • Trying to solicit Daniel to develop Mott DAQ/analysis at UITF

Marcy - list any UITF gun and beam line jobs or repairs to make photocathodes reliably, improve vacuum for high current lifetime studies

• garages in y chamber to avoid charging viewers
• determine status of Matt's mini-puck loader
• Likely need to add pumps to Mott chamber and use instead of dump line DP can

Carlos - evaluate energy reach of gun and Wien filter for experiments in the Apr 21 - Sep 21 time frame

• we'll plan for 200 keV, but no conflict if we were to operate at higher voltage (could be useful)
• Upgrade Wien filter OK, making it 200 keV for CEBAF, but 350 keV may not be possible just yet (with this Wien)
• Install Blue UITF Wien at some point...figure out when?

Mamun - develop plans to modify the 1137 and UITF depo chambers to test and finally transfer Cornell recipes to UITF photo-gun

Joe - evaluate keV-Mott Mott for operating in 100-300 kV range and for high current lifetime studies

• Xavi Aug 24...will start working on keV Mott (CS,S,TU)

Action Items

• Get IHWP/RWP wave plates at UITF
• Ask Scott to order 19" crate, small helicity board crate + isolation transformer + STAC5 controller for the Mott
• Do we add detectors at 60 deg (we have old detectors, pre-amps, plus enough spare channels of bias+amp)
• Do we need new/different collimators; lower Z???, lead around detectors, need more collimators/parts
• Improvements to the beam line when adding Mott (viewer charging)
• Develop draft/layout of the Mott line (how to put Mott in, steering magnets, focusing magnet?, valve, viewer/harp?)
• What does the bottom of chamber look like (pumping, accepts long target ladder?)
• What selection of targets do we want (higher Z => larger analyzer power/CS and vice versa)
• What target foil inventory list?!?! => do we have foils to use, or buy some from Lebow?
• What about the gun needs to be fixed to have a high lifetime program...
• HV chamber

Eliminate field emission for lifetime measurement and low current Mott measurements

Carlos recently processed UITF SS cathode + small shed to 250 kV to reduce FE'er but still exists, can it happen or do we need larger electrode?

HV chamber is mis-aligned, need preserve good laser launch/retroreflection

• Prep chamber:

Align LM to cathode electrode => no scraping, align the SM1/2/heater all to the heater stalk, mask

Matt has an load upgrade chamber...what's the plan?