1. SLSP 5246-4 activated well on April 7th
Used LLGUN2 modestly for remaining SAD and Physics start-up OK through April 24th

2. Field Emission begins? on April 24th (QE has fallen significantly already)…

3. Opportunistically hi-pot HV chamber on 4/27.
Reach ~120kV each time … finally, viewer flashes (light, not electrons?)
Anode current reduced from ~60pA to ~30pA
Wafer preserved in PREP =>

4. Beam orbit drifting for last few days (over April-May weekend…)
Tunnel investigation on May 1
Lasers check out OK
Hall B laser spot fixed (result of bad beam tweeking…)
QE now very bad (max ~0.07%)
Found anode isolation bad (30k Ohm instead of 50 Ohm)
Limp along with spot moves, but QE falls rapidly….

5. FE emission begins 4/24, orbit drift with hi-potting 4/27, but stabilizing ….

6. Gun2 wafer activated May 6th very well (1
Gun2 wafer activated May 6th very well (1.2%), OK for program, but continues to drop…
Connected picoammeter to anode for investigation (anode connection good)
Anode current >20pA always (except when HV off)
Calibration of HVPS/anode suggests ~120nA FE per 1pA of anode current
Anode current: <50pA beam ON, but up to 150pA when beam OFF

7. May 11th : Vacuum burps even when HVPS has been off… vary IP voltage
May 11th : Vacuum burps even when HVPS has been off… vary IP voltage? Ground cage?