2012/12/04
| 1010 | Fed Cricket 3 pellets. So many bubbles! |
|---|---|
| 1038 | Filled LN2 cold trap full. Mixing chamber temp is 68.6 mK |
| 1122 | Mixing chamber temp stabilizes at 68.9 mK. |
| 1124 | DCRC33 plugged into Dib 1. |
| 1157 | DCRC33 powered in Dib 1 |
| 1158 | Clock started for DCRC 33. |
| 1200 | It looks like the charge channels for board 33 are railing. That's very unexpected. |
| 1208 | Tried turning on FET heater for a couple minutes to see if the board would stop railing, but that didn't work. Powered down DCRC33 and removed it (temperature is decreasing again). Noticed that the longer screws were not used to secure the board into the ebox. Not really sure that has an effect. Going to do a quick electrical check now. |
| 1226 | Electrical check seemed fine for Dib 1. SQUID bias to return for channels B and C no longer are above 200 Ohms. Waiting for temp to stabilize again before putting DCRC33 back in. |
| 1243 | Pressures in G1 and G2 are 60 and 57 mbar, respectively. |
| 1258 | Temperature seems to be stable around 69.3 mK. Plugged in DCRC33 again. |
| 1301 | Plugged in power cable for DCRC 33. |
| 1302 | Turned on clock. There is a slight rise in the temperature, less than half a mK. |
| 1307 | Charge channels still look like they're railing, but the temperature isn't rising to reflect this. Slightly confused. |
| 1733 | I should have been documenting my efforts the whole time to figure out what's going on with the DCRC boards, but then that would have negatively impacted my frustrating experimentation. So I'll document it now in a summary. |
|---|---|
| The goal was to test each board one at a time to see what heat load is applied when each board is inserted. This was done because yesterday it appeared that the temperature would rise dramatically from the insertion and powering of a board in one of the Dibs. Because DCRC 33 is our friendliest board (aka least problematic) and its designated place is generally Dib 1, it was plugged in first. However, when powering the board and turning on the clock, it appeared that the charge channels were railed. The mixing chamber temperature didn't rise, though (see time stamp @ 1307). | |
| The next test was to see if it was DCRC 33 that was the problem, or if it was Dib 1. To test this, DCRC32 was placed in Dib 1 and DCRC 33 was placed in Dib2. First, only DCRC 32 was connected through the POE switch and putty. One charge channel looked railed while the other oscillated (around 2 V), but the temperature wasn't increasing, and turning on the FET heater didn't work, which I found very puzzling. What this suggested to me was that Dib 1 was faulty. | |
| DCRC32 was powered down and unplugged, and then DCRC33 was plugged in and powered. I was mostly expecting to see functioning charge channels, but again they looked railed. Turning on the FET heater didn't work. So this led to other suspicions and skepticism. BOTH Dibs can't be faulty. Maybe it's more likely that both boards are faulty. However, all three were working fine two days ago when the detector was being flashed. I did notice in the meantime that the POE switch board didn't have as many flashing lights. Also, the power reading was still saying 120 W. This suggested that the POE switch might be the cause for the weird feedback from the boards. It was decided to unplug the switch and re-plug it back in to see if this had an effect. | |
| To turn off the POE switch, it has to be unplugged. Very coarse, I know. This was done, and DCRC32 was re-powered. It took a little while for this to register with the computer, because the putty session was randomly closed on me. However, after that I noticed that all the lights were flashing appropriately for DCRC32 (and it was using port 8), and there was less than 120 W available. I ran the detector readout VI, and I was able to turn on the FET heater to restore the charge channels via DCRC32 properly. Success! | |
| Success did not extend to DCRC33. I plugged in a cord for DCRC33, turned on the clock, made sure the board was powered, and ran the readout VI. The charge channels looked strange (wiggly around 2 V). Turning on the FET heater did not improve them. Both boards were powered at the same time, which I know causes some interference, but it should affect the performance of DCRC32 in the manner that it has. I'm not sure enough power was being supplied to DCRC33 (voltage reading was about 111 W), and not all of the lights were flashing for port 7 (associated with DCRC33). Furthermore, the temperature started to rise, though the FET was not on, and I had to power down both boards. The temperature kept increasing, so I removed DCRC33's cord and unplugged the board. Soon after, the temperature started to decraase (t was at ~ 73.5 mK). | |
| I am puzzled. I'm not sure if DCRC33 is being problematic as well as the switch board. DCRC32 DID work after re-cycling the power. The next attempt might be to see if DCRC33 could be powered properly through the old method (need to find that equipment). I have been waiting for the temperature to stabilize (it's almost there) and then I will make some sort of move. |
| 1819 | Going to take out DCRC32, since it's confirmed to work, and put DCRC33 back in. If it acts strange, I will a) throw up my hands, and b) try port 6. |
|---|---|
| 1830 | G1 ~ 60 mbar, and G2 ~ 52 mbar. The difference between the two pressures has been slightly increasing as the day progressed. |
| Fed Cricket | |
| 1836 | Filled LN2 cold trap. |
| 1853 | Plugged in DCRC33 into Dib1 and used cord from Port 8 to power it. |
| POE reading: 120 W Lights: only one rd 30: 0800 |
|
| 1857 | Tried pushing cord in Port 8 further in, just to make sure connection is secure. The one light turned off. Typed “reset” into putty, but session didn't disappear. Weird. |
| 1859 | Woah- there was a temperature spike while I was taking out the cord from DCRC33 and plugging it back in. Temperature is decreasing quickly, though. |
| There was absolutely no connection to the board this time. Taking out cord directly from the POE this time. | |
| 1903 | Re-inserted cable back into port 8. |
| POE reading: 111 W Lights: two rd 30: 0800 mixing chamber temp: 69.4 mK |
|
| 1906 | Testing readout with readout VI: SUCCESS!!!!!!!!! |
| 2000 | It was pseudo successful. The temperature rose to 81 mK, about a 12 mK increase. It is slowly decreasing now. |