| 1115 | Remove He cold trap from condensor line and attach thin copper pipe directly to condensor line speedivalve port on fridge. Attach blanked off He cold trap to leak checker in preparation for leak check. |
| 1230 | Attach scroll pump to exhaust lines of He3 pump and pump down G2, which was at ~37mbar. |
| 1250 | Fill LN2 cold trap full. G2 at 0mbar. |
| 1255 | Open V1 and V5 to pump out condensor line which had been exposed to atmosphere. Condensor line speedivalve and gate valve still closed. |
| 1400 | Disconnect scroll pump from He3 pump exhaust lines and connect to 1K Pot Pumping line. Pump out main bath. |
| 1430 | Add 3.0 mbar He exchange gas to IVC. Add 289 mbar He gas to He-3 pump exhaust. Connect turbopump to speedivalve on He3 pump inlet lines before V6 in order to pump out condensor line. |
| 1505 | Open V3 and V1. Commence pumping out condensor line with turbopump. |
| 1530 | Commence LN2 transfer. Remove cold trap 1 from LN2 dewar and begin pumping on it with scroll pump. |
| 1615 | Stop pumping on LN2 cold trap 1. |
| 1715 | Background leak rate of 2.0E-10 mbarL/s for blanked-off helium cold trap connected directly to leak checker. Commence heating up He cold trap. Leak rate spiked to 1.5E-9 mbarL/s when heating region between 1-2' from bottom of cold trap and decreased after removing heat gun. This may be the sign of a blockage removed when heating the trap. Continue heating cold trap with leak rate continuing to spike to levels of ~7E-10 mbarL/s. The spikes reoccurred only by moving the heat gun closer to the top of the cold trap. This could be due to a blockage moving slowly up the cold trap as it is heated. |
| 1750 | End LN2 transfer. After cooling, He cold trap background leak rate is at 1.6E-10 mbarL/s and continuing to slowly drop. |
| 1800 | Commence leak check of He cold trap with background rate of 1.5E-10 mbarL/s. |
| 1820 | During He cold trap leak check, checks of the trap itself as well as the bellows showed no sign of a leak. However, the flange connecting the fridge side bellows to the leak checker showed a large leak that spiked the leak rate to well above 1.0E-9 mbarL/s, and caused a long lasting background. It is uncertain if this is due to the connection used, or the end of the bellows. Thus tomorrow we shall reattempt leak check with new flange and (hopefully) reduced background. |
| 1840 | Throughout day G2 has risen from initial 289 mbar to 391 mbar. These increases seem to come in spikes (possible due to other work on the fridge?). For fear of leaving overnight, pump He gas from G2 through V13A (cold trap 1 is being pumped on), once G2 reaches 0, continue pumping for 10 minutes. Close V13A, with no initial rise in G2. Leave overnight to see if any increases occur. |