| 1130 | Flow had ceased overnight. Increase V6 to continue cryocleaning. |
| 1150 | Mixing chamber temperature at 79.8 K. Not sure why this hasn't dropped further, but I assume it is due to gasses trapped in the inner cans. We will proceed with He transfer. With leak checker background rate of 1.2E-8 mbar*L/s, start flushing the main bath with He to blow out all LN2. |
| 1055 | Fill LN2 coldtrap full. |
| 1310 | Finish blowing out nitrogen. Leak rate steadily increased to 3.8E-7 mbar*L/s during process, though this seems more likely to be due to increased background levels than a leak. Continue with caution. Begin pumping out the main bath. |
| 1430 | Cease cryocleaning and start pumping mixture to dump. |
| 1530 | Gave an offering of dried fish flakes unto the aquatic lord. |
| 1620 | An issue occurred where the main bath would not pump out below 40 mbar. After first testing thoroughly to ensure the issue was not with the rotary pump or with a leak somewhere leading to the main bath, we decided to check that all the nitrogen had been blown out. During this time the mixing chamber temperature had been steadily (though very slowly) dropping from 79.4 K to 79.2 K, further indicating that nitrogen was still present. Since the He4 pump could not pump the main bath below 40 mbar, even after multiple attempts of flushing the main bath with He, it is likely that a large portion of LN2 remained in the bath. The transfer stick was placed back in the (at the time overpressurized main bath) and the pressure in G3 rose from ~150 mbar to ~400+ mbar (speedivalve in front of He4 pump was closed to prevent any issue), and no flow was detected at the end of the hose. When the transfer stick was lifted slightly (~1/8-1/4 in) flow started and the pressure in G3 dropped to ~150 mbar. This low of a pressure in G3 typically indicates that only He gas is flowing through the line. After several more attempts of lowering the transfer stick onto the cone and maintaining flow through the stick and hose, the He gas ran out. It was then decided that a blockage in the transfer cone was restricting the flow of the LN2 to the transfer stick. |
| 1827 | Isolate mixture in the dump (G2=630.0 mbar). Close all valves on the IGH and turn of the rotary pump. |
| 1850 | Dewar lowered. It was determined that in fact a significant amount of LN2 was at the bottom of the main bath. Furthermore, air would not pass through the transfer cone. A wire was passed through the transfer cone, and then air was able to pass through the transfer cone. Problem solved? |
| 2010 | Come LN2 was successfully removed. The rest must be removed tomorrow. |