2011/03/17
| 0947 | Stopped flashing the detector. DCRC30 didn't respond when I connected detector control vi to it. Presumably the flashing worked last night telling from the temperature change. But I'm not sure. Cycle the power of DCRC30. DCRC33 worked fine. |
|---|---|
| 1003 | Fill N2 cold trap full |
| 1126 | Started taking data 07110317_1126_F0001. Bias -3V on Q1-4. Trigger: Q1 OR Q2 OR Q3 OR Q4. Threshold: 40 ADC bins. DIB2→Detector 1, DIB1→Detector 2. |
| 1600 | Stop run. Start flashing detector while processing data; same settings as yesterday: DIB1 LED1, 0.6 mA, flash ON time 100 μs, flash OFF time 2500 μs; DIB2 LED1&2, 0.6 mA, flash ON time 100 μs, flash OFF time 2500 μs. |
| 1800 | Fill N2 cold trap full. |
| Realise charge biases were not set to 0 V before flashing. Interrupt flashing, set biases on all charge channels to 0 V, and start flashing again. | |
| 1910 | Stop flashing detector. Wait for detector to cool down. |
| 1925 | Take random noise traces at varying bias voltages: |
| Data File | Bias on all Channels [V] | No. of Random Triggers | DCRC Configuration File |
|---|---|---|---|
| 07110317_2004_F0001 | 0.0 | 2000 | DCRC_00Vbias.xml |
| 07110317_2012_F0001 | -0.5 | 2000 | DCRC_05Vbias.xml |
| 07110317_2017_F0001 | -1.0 | 2000 | DCRC_10Vbias.xml |
| 07110317_2022_F0001 | -1.5 | 2000 | DCRC_15Vbias.xml |
| 07110317_2030_F0001 | -2.0 | 2000 | DCRC_20Vbias.xml |
| 07110317_2035_F0001 | -2.5 | 2000 | DCRC_25Vbias.xml |
| 07110317_2045_F0001 | -3.0 | 2000 | DCRC_30Vbias.xml |
| 07110317_2053_F0001 | -3.5 | 2000 | DCRC_35Vbias.xml |
| 07110317_2059_F0001 | -4.0 | 2000 | DCRC_40Vbias.xml |
| 07110317_2105_F0001 | -5.0 | 2000 | DCRC_50Vbias.xml |
| 07110317_2110_F0001 | -6.0 | 2000 | DCRC_60Vbias.xml |
| 07110317_2116_F0001 | -7.0 | 2000 | DCRC_70Vbias.xml |
| 07110317_2122_F0001 | -8.0 | 2000 | DCRC_80Vbias.xml |
| 07110317_2143_F0001 | -9.0 | 2000 | DCRC_90Vbias.xml |
| 07110317_2153_F0001 | -10.0 | 2000 | DCRC_100Vbias.xml |
Charge Noise PSDs
There appears to be no correlation between bias voltage and low frequency noise. Just under 25% of events remain after cut on random triggers. At first glance, it looks as though pulses do sneak in, but using a stricter cut yields no difference.
Note different y-axis scale in Figure 1.
| Figure 1: Charge Noise PSDs for Q1 at varying bias voltages |
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| Figure 2: Charge Noise PSDs for Q2 at varying bias voltages |
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| Figure 3: Charge Noise PSDs for Q3 at varying bias voltages |
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| Figure 4: Charge Noise PSDs for Q4 at varying bias voltages |
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