| 0005 | Start data acquisition with Ba-133 source 6“ below top of mu-metal shield. Have removed part of the top poly-lead castle in order to insert the source. Pulses look fine in test run, although trigger thresholds may be a little low and as a result we are triggering on some noise. I don't think this will be a problem, but perhaps something to keep in mind when we conduct the analysis. |
| | Flash for one hour, followed by cool down for 2 hours. Then take 3 hour-long data series at -/+4 V bias, followed by three 60-minute data series at +/-4 V bias. Flash all LEDs for 6 seconds between data series with usual settings, and wait 20 minutes for cryostat to cool. Finish with a 20 minute flash and 2-hour cool down. |
| 0025 | Fill N2 cold trap full. |
| 1000 | Fed Cricket 4 pellets. |
| 1137 | Filled LN2 cold trap. |
| 1520 | Pressure in G2 has been rising (reached 87 mbar). Stopped circulation (closed V1, V6, V13A). Pump mixture to dump. |
| | Temperature has been rather erratic during data acquisition last night. Mixing chamber seemed to cool to around 60 mK before most series started, with of course the exception of the first series. The cryostat continues to cool to a little above 59 mK before the run ends and the LEDs start flashing again. |
| | However, data series 07121017_0713 (first +/-4 V series) was not preceded by LED flashing. One assumed that this is a DAQ problem, but we've never noticed this before. Other series may have been affected in the past without our knowledge. Having said that, this series occurs 62 minutes after the start of the previous series 07121017_0611, which is a clear indication that there was no flash. This pattern does not appear to have been repeated in other data sets, which would imply that flashing did precede them. Something to keep an eye on in future though. |
| | It may be worthwhile taking another set with an increased trigger threshold of 25 ADC bins (up from 20 ADC bins) as pulses were fairly noisy and these are Ba-133 runs so we are interested in the 356 keV line. |
| 1537 | Isolated valves on right hand side. |
| 1552 | Closed needle valve and speedivalve to 1 K pot. Closed V4A. Switched yellow valve to Exhaust. Turned off He4 pump. |
| | Made sure all valves on auxiliary side are closed. |
| | Pulled out N2 cold traps. |
| 1600 | Open path from He4 pump to cold traps. Turn on He4 pump. Now pumping on cold traps as they warm up. |
| 1848 | Finished 3 rounds of heating the cold traps. Pumping on them for some time more. |
| 2000 | Stopped pumping on cold traps. Placed them back in their dewar. |
| 2015 | Begin LHe transfer (8.2%). |
| 2100 | End LHe transfer (91.9%). |
| 1910 | Let mixture cool in cold traps. Start 1K pot. |
| 1930 | Fill LN2 cold trap. Slowly open V6. |
| 2208 | Fully opened V6. |