2017/08/18 (Friday)

Status	Fridge warming to room temperature. LN2 traps warm, one pumped out. Mixture in dump (LHe cold trap isolated at around 20 K). 1K Pot needle valve open. IVC filled with nitrogen.
0855	MC (Cernox) = 237.1 K
0855	Have been pumping out LN2 Trap 1 overnight, didn't intend to. Stop pumping out Trap 1.
0900	Open LN2 Trap 2 to G1: 27.3 mbar. Pump out Trap 2 with scroll pump.
1000	By Newton's law of cooling/warming, fridge won't reach dew point (283 K) until Wednesday. So I think I'll put some N2 gas in the cryostat vacuum jacket.
1010	Put one 3m hose length of N2 gas into cryostat vacuum jacket. MC(Cernox) = 238.1 K
1035	No noticeable increase in warming rate. Put four more 3m hose lengths of N2 gas into cryostat vacuum jacket.
1055	Close 1K Pot needle valve
1200	OK, now fridge is warming more quickly. Previously 0.75 K/hr, for tau of about 78 hours - now 2.1 K/hr → tau = 27 hours. At this rate should hit dewpoint early on Sunday.
1210	MC (Cernox) = 241.1 K
1540	MC (Cernox) = 250.6 K, 3.0 K/hr, tau = 15 hours - faster now. Dewpoint could happen tomorrow morning.

Wirebonding plan for S1502

1300	Carry S1502 to wirebonding lab
	Do most of the above bonds. For DIB-to-detector use wirebonder settings: power 480/480, bond time 40/30, height 50, drop 26. For detector-to-detector: power 480/480, time 30/30, height 50, drop 10. Adjusted some of these upward because bonds weren't always working.
1530	Had problems with the wirebonder, the far end of the wire came off the spool, kind of a mess. Got to watch David from Dahlberg's lab rethread it completely, not just the needle. Will finish bonds later.