2022/06/23 (Thursday)
- Lab in-personnel: Matt, Giulia
| Status | Run 76 in progress |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side2-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC50(3)/DCRC55(1), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. |
| 1055 | MC/Coldplate = 29.2/152 mK, Still = 1.06 K / 0.090 mbar / 0 mW, G1/G2 = 120/118 mbar, 1K Pot = 45° / 1.51 K / 7.0±0.5 mbar, MB = 37.3% |
| 1110 | Fill LN2 cold trap bath |
| Messing with source mover again. I calculated from recent data (0V Side 2) where I think the position of the source is. To do this I identified the phi angle using pC/pD/pE delay quantities and selected energies 12-25 keV (lower Am lines). It's clear in phi where the Am peak is: phi = -1.89°. I used the phi distribution to select Am events and also to deselect them to get background. Then I plotted pFtime-pAtime for both Am and for background. Assuming that background represents uniformly distributed events and that pFtime-pAtime is monotonic and increasing with r (at least for r not too large), I located the Am peak position with respect to the background distribution to find r of the peak - this turned out to be 22.3 mm. That's a little outside of pF (close to where I'd estimated before). | |
| 1520 | New parameters recommended by Scott for the source mover: high-speed/low-speed/acceleration/deacceleration = 20/10/30/30 (units on first two are pulse/sec, second two are ms). Scott doesn't consider the change from the old values all that important. He has hypothesized that the previous problems may have been due to a loose resistor in the controller - now there's a replacement board and a resoldered resistor. |
| We'll try moving the source to the center (or close) under the assumption that the position now is as I've calculated it above. If it doesn't seem to work, Scott suggests switching to full steps instead of microsteps (full steps = 7.5°, microsteps are 1/4 of that). | |
| 1530 | Alpha/Beta = 112/69 microsteps - these are the assumed current coordinates of the source mover, which correspond to something close to the calculated position. Use SetAbsolutePosition.prg and put in values PX/PY = 112/69. As usual Compile, Download, Run. |
| 1545 | Try measuring resistances of coils at the connectors - for some reason they all read open. Need to think about this… |