| 1117 | ANV came in and did a quick scan of the position of the Cf source used for overnight activation while data taking on. It was clear that the source is hot enough to induce some significant dead time when close to the dewar, at about 1 m back it seems to go close to its standard ~ 10 Hz rate. We should probably get a strong source. |
|---|---|
| 1121 | ANV began flashing as I have been, “manually” until temp reaches steady state |
| 1200 | ANV start 15 minute (not including randoms) background run |
| 1215 | ANV end 15 minute data run in Bg mode and start a flash |
| 1230 | flash came to steady state turn of LEDs for cool down |
| 1300 | ANV had hiccup in DAQ and needed to close DCRCv3MultiDAQ.vi – got it fixed after realizing there was some old connection to the boards that was stale and sitting around on port 5001, so I closed those and restarted. I reloaded the standard settings which came from I:\data\run053\20150619_background\daq_n4-0VD31-p4-0VD33_0VD50.xml. The trigger was loaded from I:\data\run053\2015_06_12_Gain_Sweeps\trigger_D31_D33_D50_ph_OR.xml |
| 1325 | ANV decided to do some in-situ tuning to get offsets to put the baselines at -0.8 V on all channels. Did this (see table below), but noticed that DCRC 50 (DIB 3) was saturating at a seemingly low level, so started looking into this a bit. |
| 1415 | ABK filled LN2 cold trap |
| 1511 | ANV stopped tinkering with the thresholds and lockpoints to try to change the saturation – basically I couldn't. Flash and do another run to see what we have |
| 1612 | ANV some channels railed, had to adjust before Bg run, 07150621_1606 is junk |
| 1751 | ANV changed to only flashing for a few seconds, sort of “rapid-fire” Bg runs with Cf activation during cooldown |
Saturation
Found channels saturating after first Bg series _1200 at the following values
| DIB | A (V) | B (V) | C (V) | D (V) |
|---|---|---|---|---|
| 1 | 0.5 | 0.6 | 0.45 | 0.45 |
| 2 | 0.65 | 0.55 | 0.65 | 0.52 |
| 3 | 0.3 | 0.35 | 0.1 | 0.2 |
It seems DIB 3 has the “lowest” saturation values. These were measured in Volts on output, so they don't really mean anything independent of the gains. But for equal gains DIB 3 has much lower saturation, this should be checked somehow..
New Driver Offsets
After the _1200 run, the offsets were changed to line all the pulses up at their baseline near -0.8 V.
| DIB | A (V) | B (V) | C (V) | D (V) |
|---|---|---|---|---|
| 1 | 0.032 | 0.020 | 0.024 | 0.036 |
| 2 | 0.034 | 0.046 | 0.034 | 0.028 |
| 3 | -0.086 | -0.02 | -0.122 | -0.136 |
After starting the next run, they had to be changed again and the run re-started. Only DIB2 C and D were changed to -0.016 and -0.026 respectively.
Cool down times
If I flash until we reach steady-state which is around 280 mK, I typically wait 20 minutes to cool. I am now finding that it actually takes about 40 minutes to really reach base temp. in the first 20 minutes it goes all but about 1 mK though, does this matter? In a recent Bg series the Am peak seemed wider than it should be in charge – I don't see how this is base temperature dependent, at least not as much as phonons, but it's a mild worry.
Procedure for data taking (from voltaged state)
1. Use Detector Control to set the voltages to zero on DIB 1 (DCRC 31, .116) and DIB 2 (DCRC 33, .84) 2. Use the putty sessions to turn on the two working sets of LEDs (DIBs 2 and 3) for 5 seconds 3. Restore the Cf source for activation 4. Observe the temperature spike to around 114 mK and wait to get within 1 mK of target on cooldown 5. Remove the Cf source 6. Use Detector control to set the voltages to the correct values 7. Start data using MultiDAQ and be sure all phonon and charge channels that should be there are there 8. Wait until the randoms end (event 1000) and start a timer for 15 minutes 9. When 15 minutes is over stop the run on the MultiDAQ and repeat