2012/10/27
| 0045 | Fill N2 cold trap full. |
|---|---|
| 0230 | Conduct charge breakdown measurements. The results would indicate a suitable range of biases to lie between +/-4V and -/+2.5 V. Charge collection efficiency may be rather low at -/+2.5 V. |
| Side 1 (S1) positive | |
|---|---|
| Bias (S1/S2) [V] | Comment |
| +/-1 | Fine |
| +/-2 | Fine |
| +/-3 | Fine |
| +/-4 | Qi DIB 1 has some strange pulses, but probably fine. |
| +/-5 | Qi DIB 1 looks noisy. |
| +/-6 | Qi DIB 1 looks noisy, but no more than previous bias; A3 & B3 very rarely show signs of breakdown. |
| +/-7 | Qi DIB 1 looks noisy, but no more than previous bias; A2, B2, D2, A3, C3 & D3 occasionally show signs of breakdown. |
| +/-8 | Qi DIB 1 looks noisier, worse than previous bias; all phonon channels occasionally show signs of breakdown. Stop here as Qi has been far too noisy to take data with a long trace length for a few biases. Declare complete charge breakdown. |
| Side 1 (S1) negative | |
|---|---|
| Bias (S1/S2) [V] | Comment |
| -/+1 | Fine |
| -/+2 | Qi DIB 2 looks a little wavy on occasion, but PSD looks fine so probably alright. |
| -/+2.5 | Occasional waves in Qi DIB 2 trace. |
| -/+3 | Qi DIB 2 looks rather noisy; D1, A3, B3 & D3 show small hints of breakdown. |
| -/+3.5 | Qi DIB 1 beginning to wave a little; Qi DIB 2 all over the place; D3 occasionally shows signs of breakdown; A2, B2, A3 & D3 very rarely show signs of breakdown. Qi DIB 2 has been far too noisy to take data with a long trace length for -/+3 V and this bias. Declare complete charge breakdown. |
| -/+4 | Qi DIB 2 all over the place; all phonon channels on DIBs 1 & 3 very rarely show signs of breakdown; A2, B2 & D2 show signs of breakdown at a higher frequency. |
| 0250 | Start charge-only data acquisition, 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 +/-2 V, -/+2 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. |
|---|---|
| Rate of data acquisition varies between 7-10 Hz. Everything looks fine. | |
| 0320 | Fill N2 cold trap full. |
| 1710 | Fill N2 cold trap partially; perhaps a litre shy but good enough until later this evening. |
| Fed Cricket 4 pellets. | |
| Overnight data acquisition appears to have completed without any problems. Cryostat is currently cooling from final flash, and a flash was present before all data series were taken. Current mixing chamber temperature 63 mK and falling. | |
| 1750 | Commence helium transfer. Helium liquid level 29.6%. |
| 1845 | Cease helium transfer. Helium liquid level 92.4%. |
| Dib1/2: +/-2 V | |
|---|---|
| 07121027_0556 07121027_0647 07121027_0737 07121027_0827 |
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