| 0125 | Mixing chamber temperature 2.4 K. Pressures in G1 & G2 96 mbar & 80 mbar respectively. Switch mixing chamber thermometer to H35. Isolate dump and close valve V3 on IGH. Start manual circulation procedure by slowly opening valve V6 on IGH. |
| 0340 | Valve V6 on IGH fully open. Cease manual circulation procedure. Mixing chamber temperature 158 mK and falling. |
| 0410 | Reduce 1 K pot temperature to 1.66 K. |
| 0435 | Fill N2 cold trap full. |
| 1530 | Fill N2 cold trap full. |
| 1835 | Finsihed erecting half of poly-lead shield around cryostat. |
| 2100 | Extracted most of mixture from dump (pressure in P1 was 0.18 mbar). Close valve V14 on IGH and wait for circulation to stabilise. |
| 2215 | Still pressure 0.15 mbar and thermometer reads 4.51 kΩ. Cold plate thermometer reads 11.5 kΩ. High pressure in still probably indicates that it is indeed overflowing. However, cold plate thermometer shows a far lower temperature than what was achieved with a smaller amount of mixture; this may be due to the increased circulation rate. The mixing chamber temperature is 123 mK. Pressures in G1 & G2 are 142 mbar & 137 mbar respectively. |
| 2225 | Commence single shot test. Due to high pressure of still, it is likely that some He-4 will be extracted too. |
| 2240 | Something is wrong as mixing chamber temperature has not dropped yet. This would imply that the phase boundary does not lie in the mixing chamber. Still heater hasn't been adjusted to compensate for decreasing still temperature, but this hasn't affected our measurements in the past. Additionally, increasing the still heater would cause more He-4 to evaporate, thus diluting the collection of He-3. Finally, the rate at which the dump pressure is increasing appears to be linear, implying that the decreasing still pressure does not affect the rate of recovery. |
| 2250 | Abandon single shot test. Mixing chamber temperature did start to decrease, but only by a few mK and then started behaving rather erratically. Not sure how to interpret this result, but it looks as though this is a waste of time. Better to recondense a smaller amount of mixture and start taking data. This can be followed by a single shot test to determine the position of the phase boundary. |
| | Stop 1 K pot and turn on mixing chamber heater to 10 mW in effort to recover mixture. Start pumping mixture into dump. |