| | Setup: DIB 1/3/4 → 3.2 MHz filters 1/2/3 → cable 1/3/2 → gender changers → rerouting boards 1/3/4 → DCRC55(1)/33(2)/50(3) |
| | Overnight bias scan data had some problems. DCRC2 had low frequency 10-100 Hz noise on its baseline. Starting with the second data series (_1813) there was strange triggering behavior. There are sets of ~10-20 good pulse triggers followed by scores of rapid triggers on noise traces. This is the case for all but the first series of data taken last night. Confirm that there was no instance of SQUIDTuning GUI running during the scan. |
| 1726 | Fill LN2 cold trap |
| 1732 | Tower/MC/Coldplate = 83.9/56.6/363 mK, Still = 1.27 K / 0.20 mbar, G1/G2 = 241/229 mbar, 1K Pot = 1.63 K / 30 mbar. MB = 49.7% |
| 1850 | Let's try running this sequence again. Hopefully the triggering will behave. |
| 1852 | Start charge_bias_scan_R65 sequence with 1000 beginning randoms, and a 40/30/15/40/40 ADC bin threshold trigger on DCRC1qI/qO/DCRC2qO/DCRC3qI/qO, with trigger baseline = 32 samples and trigger length = 10 samples (these are 2x the usual values). This will scan through DCRC biases of 0, 3, 6, 9, 12, -3, -6, -9, -12 V Later: Realized there was an error in the sequence so DCRC3QI was stuck at 0 V bias. |
| 1857 | First data out looks to be triggering properly. |
| 2102 | Now raw traces have a bunch of noise triggers. Raise all trigger levels by 10ADC at 29th minute of 6V ( _2035) series. |
| 2114 | That seems to have worked. The 30th dump seems to be triggering properly. Perhaps applying the DCRC bias adds just enough noise to overwhelm the trigger levels I'd set. |
| 2115 | Stop the sequence early during a cooldown. |
| 2129 | Start charge_bias_scan_R65 sequence with 1000 beginning randoms, and a 50/40/25/50/50 ADC bin threshold trigger on DCRC1qI/qO/DCRC2qO/DCRC3qI/qO, with trigger baseline = 32 samples and trigger length = 10 samples (these are 2x the usual values). This will scan through DCRC biases of 0, 3, 6, 9, 12, -3, -6, -9, -12 V Later: Realized there was an error in the sequence so DCRC3QI was stuck at 0 V bias. |
| 2323 | Gah, again the first series triggers fine, but the second, at 3V starts triggering on noise. What's going on here? Try setting all the triggers to their same current values in ODB (i.e. just retype the number and hit enter) during dump 10 of series _2312. This doesn't change triggering behavior. |
| 2327 | Stop the sequence, stop the current run Leaving all settings the same, including triggers and 6V DCRC biases, start another run from the Midas front page. Nope, same noise triggering behavior. Why were these trigger levels okay for 6V a few hours ago but now trigger on noise? |
| 2335 | 8.5 min into series _2327, disable DCRC3QO triggering. Doesn't help. |
| 2340 | almost 13 min into series _2327, disable DCRC3QI triggering. Doesn't help. |
| 2345 | 17min into series _2327, disable DCRC1QI/QO triggering. Now it's triggering well on pulses only on DCRC2. |
| 2349 | I'm not sure what's up here. Could be that the noise is changing enough to make triggering behave differently over time, but the baselines don't seem to be changing qualitatively. |
| 2350 | Begin 5 hour bake. |