previous day
| 0836 | Filled LN2 cold trap full |
| 0840 | Tower/Cold Plate = 31.5/151 mK, Still = 1.33K/0.11 mbar, G1/G2 = 155/150 mbar, 1K pot = 1.74 K/24 mbar, Main Bath = 72.5% |
| 0926 | Variac was sitting on equipment rack near Lakeshore bridge. Found that while the variac was powered, Still temp was reading artificially high ar around 1.33K. When the variac was switched off, the Still temp reading fell to a more normal value of 1.1K |
| 1200 | Transfer stick was cold on previous transfers. Pumped transfer stick down to < 1e-1 mbar using scroll pump. |
| 1330 | Look for Tc transitions in HV1 pA,B,C. QET bias = 0, send 10mVpp 100Hz signal down QET lines. base = 31.4mK. |
| HV (V) | I_leak (nA) | Tower temp (mK) | TES status |
| 12.42 | 17.8 | 31.4 | small phonon signal = normal |
| 10.93 | 14.7 | 31.4 | large phonon = superconducting |
| 11.31 | 15.5 | 31.4 | increasing HV, A then B then C go normal |
Connecting a single probe to I_leak test point produces 60Hz noise in charge signals and drives TESs superconducting (cooling!?!?) Tower temp unaffected.
| HV (V) | I_leak (nA) | TES status |
| 11.29 | 15.8 | all SC |
| 13.03 | 19.3 | A then B then C go normal. Return to SC after a minute. |
| 13.94 | 21.4 | normal. Probes drive them SC, but return to normal after removal. Eventually go SC again after a minute. |
Switch to increasing HV until TESs go normal, waiting for them to return to SC, then measuring I_leak
| HV (V) | TES status | I_leak (nA) |
| 14.29 | normal, 1min, then SC | 22.3 |
| 14.89 | “ | - |
| 15.49 | ” | 24.9 |
| 16.16 | “ | 26.3 |
| 17.00 | normal, not returning to SC after 5 min. Probe drives them SC | 28 |
| 17.51 | normal, few minutes, SC | 29.3 |
| 18.48 | normal, few min, SC | 30.7 |
| 19.01 | normal, didn't go SC after ~20 min even when measuring I_leak | 32.2 |
| 1800 | Filled LN2 trap full. |
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