2019/05/13 (Monday)

Previous Day

Status	Warm after hitting fridge blockages, 3 times. Cryostat vacuum jacket and IVC both pumped out.
Setup	DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2
0755	Fill LN2 cold trap bath
0800	Mixture has been open to cold LN2 Trap 1 overnight. Pump mixture out of Trap 1 into dump. Removed 10.7 mbar.
0810	LN2 Trap 2 is warm. Check contents: 10.2-1.7 = 8.5 mbar on G1. Pump out with 4He pump.
0820	Start cryocleaning mixture through LN2 Cold Trap 2, V6 = 12.6%
0825	Increase V6 → 12.9% to restart flow
0840	Increase V6 → 13.0% to speed up flow. G1 increases by ~3 mbar as G2 rises.
0905	Increase V6 → 13.1% to speed up flow. G1 increases by ~13 mbar as G2 rises.
0920	Stop cleaning through Trap 2 after 60 min. G2 flow pressure was 630-645 mbar. Pump mixture to dump. Removed 4.1 mbar.
0935	LN2 Trap 1 is mostly warm. Check contents: 12.5-1.8 = 10.7 mbar on G1. Pump out with 4He pump.
0945	Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 12.9%. G1 falls by ~8 mbar as G2 rises.
1030	Increase V6 → 13.0% to speed up flow. G1 falls by ~4 mbar as G2 rises.
1045	Stop cleaning through Trap 1 after 60 min. G2 flow pressure was 585-750 mbar. Pump mixture to dump. Removed 6.6 mbar.
1055	LN2 Trap 2 is mostly warm. Check contents: 5.6-1.5 = 4.1 mbar on G1. Pump out with 4He pump.
1150	Start cryocleaning mixture through LN2 Cold Trap 2, V6 = 12.7%.
1200	Increase V6 → 12.9% to restart flow
1220	Increase V6 → 13.0% to speed up flow. G1 increases by ~5 mbar as G2 rises.
1250	Stop cleaning through Trap 2 after 60 min. G2 flow pressure was 575-630 mbar. Pump mixture to dump. Removed 2.8 mbar.
1305	LN2 Trap 1 is mostly warm. Check contents: 8.6-2.0 = 6.6 mbar on G1. Pump out with 4He pump.
1320	Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 13.0%.
1325	Increase V6 → 13.2% to restart flow. G1 falls by ~4 mbar as G2 rises.
1440	Stop cleaning through Trap 1 after 80 min. (Flow seems to have stopped some time before the end.) G2 flow pressure was 575-635 mbar. Pump mixture to dump. Removed 2.0 mbar. This is encouraging, but it should be noted that this was after the mistake at 15:20 - some of the contamination from the trap may have already escaped before the final pumpout.
1500	LN2 Trap 2 is mostly warm. Check contents: 4.5-1.7 = 2.8 mbar on G1. Pump out with 4He pump.
1520	Screwed up while preparing to start a Trap 2 cleaning, accidentally let mix into Trap 1. Trap 1 had been out of the bath for about 15 minutes. Pumping it back to dump now, may have let a little of the contamination back into the mix. Put the trap back into the bath before I started pumping it out.
1540	Start cryocleaning mixture through LN2 Cold Trap 2, V6 = 13.3%.
1555	Increase V6 → 13.4% to restart flow. G1 rises by ~2 mbar as G2 rises.
1645	Stop cleaning through Trap 2 after 65 min. G2 flow pressure was 570-605 mbar. Pump mixture to dump. Removed 11.8 mbar. Crap, that's high again. Could be because I accidentally let contaminants into the mix from the preceding cleaning.
1655	LN2 Trap 1 is mostly warm. Check contents: 3.8-1.8 = 2.0 mbar on G1. Pump out with 4He pump.
1730	Set up passive cleaning with both sides of dump and pump contents exposed to Trap 1. With 3He pump on, open V9, V4, V12A+speedi, and V13A.

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