2019/09/09 (Monday)
| Status: warming up. All mixture in dump. LN2 Cold Trap 1 warm and ready to pump out. Small amount of He gas in IVC and cryostat vacuum jacket. 1K Pot needle valve open. | |
| 0700 | Recovery meter = 312596.19 cuft. Recovery rate = 1 cuft/23 hours. |
| 0910 | MC(Cernox) = 181.6 K |
| 0915 | Let 8.6 mbar N2 gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum jacket → 400 ubar |
| 0925 | IVC = 140 mbar on Pfeiffer gauge, but near 0 on mechanical gauge. Pfeiffer gauge isn't reading correctly. Let a little N2 into IVC - Pfeiffer pressure drops to 40 mbar. |
| 0945 | Slowly let 0.62 bar of N2 gas into IVC. |
| 0945 | MC(Cernox) = 183.3 K |
| 1100 | Recovery meter = 312596.36 cuft. Recovery rate = 1 cuft/12 hours. A bit faster since adding more gas to the cryostat vacuum jacket. |
| 1145 | MC(Cernox) = 190.4 K, rising at 3.6 K/hour. This suggests a warming time constant of 28.5 hours. At this rate it will take 77 hours to reach dew point (around 55 F). That's Thursday afternoon at 4:16pm. Hopefully it will start warming faster. |
tau = (T_room - T) / (dT/dt)
t_remaining = tau * ln( (T_room-T)/(T_room-T_warm) )
T_future = T_room - (T_room-T) * exp(-delta(t)/tau)
| 1450 | Remove NaI detector wall from South side of lead/poly shield |
|---|---|
| 1445 | MC(Cernox) = 200.8 K, rising at 3.4 K/hour. This suggests a warming time constant of 27 hours. At this rate it will take 70 hours to reach dew point (around 55 F). That's Thursday at 12:35 pm. |
| 1500 | Recovery meter = 312596.63 cuft. Recovery rate = 1 cuft/8 hours. |