2011/08/31

0028	Start taking data 07110831_0028_F0001. -4V bias. Trigger on Q1-3 at 48 ADC bin. Data/flash/cooldown = 30/0.1/20min. 4 series for -4, -6, -8V biases each. Tower temperature rise to 66mK from 58.5mK after applying bias. This could be a temperature measurement problem or real crystal temperature change. Event rate ~50 Hz.
1050	'Not enough memory to complete this operation' occurred again at 03:54 File 07110831_0353_F0001.

Data collected in the last run

1.3G    ./07110831_0028
1.6G    ./07110831_0118
1.6G    ./07110831_0208
1.6G    ./07110831_0258

1058	Take data 07110831_1058_F0001. -4V bias. Trigger on Q1-3 at 48 ADC bin. Data/flash/cooldown = 30/0.1/20min. 1 series for -4, -6, -8V biases. Event rate 5 Hz. Found connection to DCRC30 was reset.
1101	After reestablishing the timing link, event rate became ~50Hz.
1104	Can not see pulses from DCRC30. Stop the DAQ.
1106	Restart DAQ, still can not see pulses from DCRC30. Stop the DAQ.
1110	DCRC30 wasn't triggering as found in the detector readout vi.
1123	Filled N2 cold trap.
1126	Qi on DCRC30 only triggered at <6 ADC bins and no pulses showed up.
1139	Resetting DCRC30 still gives the same behavior.
1143	Found the two yellow LEDs for the charge amplifier are off. Cycle the power of DCRC30.
1145	DCRC30 was back on line after cycling the power.
1149	Start DAQ again to take 07110831_1149_F0001. 1 series for -4, -6, -8V each. The DAQ looks fine. Event rate ~35 Hz. Does this mean 50Hz was only from DCRC33. Just run the DAQ for a while to make sure it works. Tower temperature rose to 65mK from 57mK after applying bias. This heating effect seems from DCRC30 only. This may draw too much current and trigger the POE switch off.
1630	The DAQ seem to work fine. Charge biases heat up the detector.

Heating effect of Q4 at -4, -6, and -8V biases

1638	Apply -4V bias to Q1 to Q4 each at a time to see which channel caused the heating effect.
1643	Found Q4 caused the heating effect. There might be a short to ground at Q4. Because of the 40MOhm bias resistor, this is not to detect once the sidecoax is attached. This can only be measured at the detector level. For now maybe the best thing to do is not to apply bias to Q4 and take data on the other three channels.
2022	Needs 80min to cool to base temperature after long time flashing.
2039	Start taking data 07110831_2039_F0001. -4V on Q1-3 and 0V on Q4. Trigger on Q1-3 at 32 ADC bin. Data/flash/cooldown = 30/0.1/20 min. 20min flashing before data. This is the 1st series of -4V data. 4 series for -4, -6, -8V bias each.
2042	The pulses look fine on the screen