Pressure:
Previous HV tests done at 2e-7 pressure.
Current pressure 1.1e-6 (see previous entry for RGA stats) - first attachment shows source gas setup. Argon, neon and He leaks all on.
Ramping up:
- Second attachment - bias at 50kV
- Third attachment - bias at 60kV
- Fourth attachment - bias at 65kV
Pressure has been slowly falling since we started this test - now down to 8.7e-7
Spark after 10 mins, see attachment 5. Very slight vacuum jump (8.5e-7 -> 1.2e-6) and bias current jump (36uA -> 113uA). Tripped TP6 and the steerers, as usual. Bias current read back more erratic afterwards (see sixth attachment).
System has been stable for 20mins, though current on bias is still more erratic than before the spark. Increasing He leak rate from 7 to 7.06 to bring vacuum back up to 2e-6 (see attachment 7). No effect from increased pressure.
Tuesday, March 13, 2018, 05:52: Power off.
Tuesday, March 13, 2018, 05:56: Waterlines purged
Tuesday, March 13, 2018, 05:57: Ion gauge, Turbos off. |