2012/02/15
| 0855 | Filled LN2 cold trap. |
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| 1614 | DCRC32 noise with the interface board. DCRC33 also plugged in but not powered up. |
| 1622 | Power off DCRC32. Power up DCRC33. Temperature spiked up from 77mK to 81mK. |
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| DCRC33 Qi noise ~15mVpp. Qo noise ~20mVpp. | |
| Ground the digital ground of DCRC33 to chassis, Qi noise ~7mVpp; Qo noise ~7mVpp. | |
| 1813 | Begin LHe transfer (9.9%). |
| 1842 | Found DCRC33 noise changes when moving the board. Noise was reduced by retightening the connection between DCRC and interface board. Grounding the digital ground to chassis also reduces the noise. I guess it's best to solder a wire. |
| 1856 | Power up DCRC32. 52kHz and 106 kHz peaks show up on DCRC33 noise spectrum. |
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| 1908 | DCRC32 Qi noise ~8mVpp. Qo noise ~8mVpp. Large 52kHz and 106kHz peaks. |
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| 2200 | Found shielding the Cat6 cable at the RJ45 connector and ground the shield to chassis kills the 55kHz and 106kHz peak. This is true for both DCRC32 and DCRC33. |
| 2211 | Temperature rose to above 100mK after isolating the bath to air. Temperature dropped after opening the bath to air. But charge signal had no change when temperature changed. Charge signal is independent of temperature at least ~100mK range. |
| 2232 | Take the noise data of the DCRCs with BNC cable attached to the interface board. |
| 2235 | Filled N2 cold trap. |
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| 2246 | Check charge breakdown voltage. Biasable interface board is connected to SL19 and DCRC32. |
| +10V bias, charge baseline stable, temperature stable. | |
| +15V, charge signal stable, temperature stable. | |
| +20V, charge baseline jumps up and down, temperature rises, 1/f component at low frequency shows up in charge noise PSD. | |
| Disconnect external bias, fridge temperature dropped. | |
| 2308 | Taking data 07120215_2308_F0001. +15V external bias, 0V DCRC bias, Ba-133 source. Temperature rose to 86.8mK, charge signal is still stable. |
| 2312 | Trigger rate became very low after the first a few minutes. |
| 2316 | Stopped taking data. |
| DCRC32 nose Qi ~8mVpp, Qo ~8mVpp, baseline jumps up and down, pulses are kind small, low f part of noise psd slightly rises. | |
| DCRC32 nose Qi ~3mVpp, Qo ~6mVpp, baseline jumps up and down, pulses are kind small, low f part of noise psd slightly rises. | |
| Raising the trigger thresholds would be able to reduce the trigger rate and take data. But this doesn't make sense here. | |
| Turn off external bias. Temperature drops. | |
| 2344 | Taking data 07120215_2344_F0001. +10V external bias. 0V DCRC bias. Ba-133 source. Temperature 81.6mk. Trigger on Q1-4 at 56ADC bin. |