2022/11/08 (Tuesday)
- Lab in-personnel: Matt
| 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. PuBe behind lead wall on W side of fridge. NaI scan in progress, not set up for coincidence data |
| Warmed up yesterday for twenty-first 5K pumpout. | |
| 1245 | Turbo on IVC = 1.0 nbar. With Turbo valved out for 1 minute IVC = 10 nbar. |
| 1250 | Turn on 4He pump. Open Recovery valve to 4He pump. Pump out line to 1K pot (speedivalve closed). Check pressure in 1K Pot (with V4a open, 4He pump inlet valve closed). 1K Pot = 0.22 bar on mechanical gauge. |
| 1250 | Pump out 1K Pot slowly, throttling the flow at the valve at the pump inlet, opening just until the pump gets louder, then waiting, then opening a little more, etc. With pump just a little loud, can see pressure go down at the mechanical gauge. When this is low, open valve a bit more. When P2 gets below 20 mbar open valve all the way. |
| 1255 | 4He pump valve open all the way. |
| 1255 | 1K Pot = 3.39 K / 2.8 mbar. G1 (fridge+dump)=529 mbar. MC = 5.67 K. |
| 1315 | 1K Pot = 3.24 K / 3.0 mbar. G1 (fridge+dump)=475 mbar. MC = 3.61 K. |
| 1335 | 1K Pot = 2.93 K / 3.0 mbar. G1 (fridge+dump)=402 mbar. MC = 3.32 K. |
| 1340 | Open 1K Pot needle valve → 15°. 1K Pot → 2.72 K / 5.0 mbar |
| 1350 | Open 1K Pot needle valve → 30°. 1K Pot → 2.57 K / 6.5 mbar |
| 1355 | Open 1K Pot needle valve → 45°. 1K Pot → 2.35 K / 9.0 mbar |
| 1400 | Trying again to get MIDAS working on cdms2. Permission problems yesterday, but now Chad has added sudo user spa-u-cdmssoft on CentOS to the proper groups. Today we couldn't get the browser to load the MIDAS interface, got the error SSL_ERROR_RX_RECORD_TOO_LONG. Chad gave us a workaround on Firefox: |
The only workaround I've seen mentioned so far was to turn off support for the newest and most secure connection protocol, TLS 1.3. Perhaps some sites or some intermediaries (security filters?) return data to Firefox that it finds invalid when this is enabled (TBD). To try that: (1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk. (2) In the search box above the list, type or paste TLS and pause while the list is filtered (3) Double-click the security.tls.version.max preference to display a dialog where you can edit the value from 4 to 3 (or in other words, from TLS 1.3 to TLS 1.2). Then click OK.
| This worked, we can see the interface now. | |
| 1520 | MC hung around 2.1 K for a while, then fell quickly to 1.6 K (lambda point) |
| 1530 | Begin LHe transfer @ MB = 33.5% |
| 1545 | MC/Still/1KPot = 1.81/1.84/1.52. G1(fridge+dump) = 41 mbar and getting flat. |
| 1545 | Close V3 and V9, leaving 32 mbar mixture in dump (G2) |
| 1545 | Turn on 3He pump. G1(condenser) → 49 mbar |
| 1550 | Fill LN2 cold trap bath |
| 1550 | Start circulation through Trap 1. V6 → 12.6%. Condenser peaks at 215 mbar. MC(H35) → 1.41 K. Still → 1.44 K / 26 mbar |
| 1555 | V6 → 13.0%. Condenser(G1) peaks at 194 mbar. MC(H35) → 1.17 K. Still(P1) → 1.21 K / 5 mbar. |
| 1600 | V6 → 13.4%. Condenser(G1) peaks at 164 mbar. MC(H35) → 1.07 K. Still(P1) → 1.15 K / 3.6 mbar. |
| MC hung up for a bit at 1.05 K, Al transition | |
| 1605 | V6 → 13.8%. Condenser(G1) peaks at 154 mbar. MC(H35) → 0.92 K. Still(P1) → 1.10 K / 1.9 mbar. |
| 1610 | V6 → 14.4%. Condenser(G1) peaks at 157 mbar. MC(H35) → 0.37 K. Still(P1) → 1.12 K / 0.8 mbar. |
| 1615 | End LHe transfer @ MB = 95.8% |
| 1620 | V6 → 15.0%. Condenser(G1) peaks at 150 mbar. MC(H35) → 0.23 K. Still(P1) → 1.11 K / 0.5 mbar. |
| 1625 | V6 → 100.%. Condenser(G1) peaks at 147 mbar. MC(H35) → 0.12 K. Still(P1) → 1.05 K / 0.15 mbar. |
| 1635 | MC = 55.0 mK. Still = 1.07 K / 0.12 mbar. G1/G2 = 128/119 mbar. 1K Pot = 1.51 K / 7.2±0.2 mbar. |
| 1640 | Open V14 to pull the rest of the mixture out of the dump into circulation. Still peaks at 45 mbar, Condenser peaks at 168 mbar, MC peaks at 81 mK, then all relax again. 1K Pot mostly unaffected. 1K Pot rose a bit, to 1.54 K / 9.5 mbar, then fell again. It's running a little low, we'll see how it goes. |
| 1705 | Still = 0.80 mbar. Close V14 |
| 1705 | MC = 32.9 mK |
| 1705 | Plug in DCRCs 1&3 |
| 1705 | 1K Pot = 1.51 K / 6.5 mbar and not oscillating. This seems to low, let's open it further. |
| 1705 | Open 1K Pot needle valve → 60°. 1K Pot → 1.56 K / 11±1 mbar. Better. |
| 1715 | Check phonon channels, relock some and adjust a couple of offsets to get baselines ~ -0.8 V |
| 2240 | Tune phonon offsets to get all baselines near -0.800 V |
| 2240 | MC = 28.8 mK |