2012/10/31
| 0100 | Start data acquistion, triggering on charge channels with 0.1 ms trigger delay and 0.4096 ms trace length. OR charge trigger threshold 40 ADC bins for all charge channels, and coincidence time set to 10 μs. Flash for one hour, followed by cool down for 2 hours. Then take four 30-minute data series each at -/+1.5 V, +/-1.5 V & -/+1 V biases. 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. |
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| As yesterday, rate of data acquisition is very low at around 1 Hz. As yesterday, phonon pulses look alright, although only saturated pulses show up. At the earliest opportunity, we should take a look at the data we collected last night and compare it with the +/-2 V & -/+ 2 V charge-only data series we took a few days ago. | |
| Pressures in G1 & G2 are 72 mbar & 68 mbar respectively. | |
| 0110 | Take advantage of detector flash to fill N2 cold trap full. |
| 1000 | Filled LN2 cold trap. |
| 1545 | Begin LHe transfer (23%). |
| 1625 | End LHe transfer (92.1%). |
| 1658 | Filled LN2 cold trap. |
| Dib1/2: +/- 2 V | |
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| 07121027_0556 07121027_0647 07121027_0737 07121027_0827 |
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| Dib1/2: -/+ 2 V | |
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| 07121027_0918 07121027_1008 07121027_1058 07121027_1148 |
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| Dib1/2: +/- 2.5 V | |
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| 07121030_0329 07121030_0419 07121030_0509 07121030_0559 |
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| Dib1/2: -/+ 2.5 V | |
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| 07121030_0651 07121030_0741 07121030_0831 07121030_0922 |
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| 2130 | From Roxanne's work earlier today, it appears as though data acquired on and after 2012/10/28 is of poor quality: no 60 keV peak is visible, although from the analysis of +/-2 V & -/+2 V data from 2012/10/27, it should be very distinct. The DAQ did crash while taking data on 2012/10/28. However, it appears as though the problem started before this: what looked like trapped flux was observed in the phonon pulses. Additionally, the trigger rate was a little poorer at 4 Hz during the test run (as opposed to 7-10 Hz on 2012/10/27). Although restoring the link to DCRC32 and zapping the SQUIDs did result in better phonon pulses, the trigger rate during the test run decreased to 1 Hz. Something is wrong, but it is difficult to determine what could have happened to trigger this. |
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| Let's unplug everything, close all vis and reset the DAQ machine. We can use this opportunity to run a Windows update too. Perhaps starting from a clean slate will get rid of whatever is causing the problem. | |
| The data taken this morning has been moved to masherbrum, but there is probably little point in reducing it. Leave it there for now - let's see what happens when we reset everything. |