Alpha background started with beam ON - run47. Run started 16:49 18/2/22   (beam subsequently found to be OFF)

Beam energy 4 keV, beam lifetime ~ 100 ms

Noticed aida01 and aida02 were showing increased good event rates to ~250,000, effect seen on spectrum browser and data writing rate increased to ~2500 kb/sec from ~20 kb/sec. ASIC check on the affected fees brought rates back to normal range 10-20k good events. Multiple instances occurred in a row on run47 so fees were power cycled. Run ended 17:21

Run 48 started after power cycle

Run start 17:42, beam OFF ~18:30-19:00 for access to the cave to aid allignment of the gas jet target.

Rates remain stable until ~20:00. Aida01 and 02 show increased rates, asic check -> back to normal range.

Beam ON 21:43

All system checks OK. All rates OK. Leakage current ~3.62 uA.

14:00 19/2/22

Beam OFF during 18/2/22 due to an interlock controlled by main control room unknown to us. Beam has been OFF. 

Leakage current plot attached. System checks OK, except white rabbit, all fail.

Motors were at 26mm potentiometer opposed to 20.2mm which was the set point (fully out 19mm). Motors dragged in as pneumatic was not fully out. Likely result of pneumatic out valve being closed. Pneumatic fully out, potentometer back to 20.2mm and leakage current drop from ~3.75 uA to 3.54uA.

Run ended 21:00