We picked up the following I/O chassis components from Downs CDS testing lab:
Let's use this entry to list of the test results of new donatella.
I tested the mixer by feeding it a 300 kHz signal sourced from a Moku:Go. I kept the LO input the same - 231.25 kHz from the signal generator. The mixer output was a ~70 kHz waveform as expected, so demodulation is not the issue in green locking.
Next I'll align the arm cavities with IR and check to see if the green REFL signal looks as expected. If not, we'll have to invesitage the REFL PD. If the signal looks fine, and we now know it's being properly demodulated, the issue must lie further downstream.
While changing out one of the N2 tanks today, one of the fitting stripped. This caused a major loss of pressure. I replaced one fitting then realized there was a second leak around the area of the gauge. Paco and I changed this and everything should be back up and running. Thhe interlocks may have been tripped within the last 2 hours.
Fields at the BHD BS. More on this later.
I've turned off HEPA fan and all lights at
PST: 2022-11-24 11:23:59.509949 PST
UTC: 2022-11-24 19:23:59.509949 UTC
c1ioo model has been updated to acquire C1:IOO-MC2_TRANS_PIT_OUT and C1:IOO-MC2_TRANS_YAW_OUT at 512 Hz rate.
I'll update when I turn the HEPA on again. I plan to turn it on for a few hours everyday to keep the PSL enclosure clean.
Turned on HEPA again at:
PST: 2022-11-25 12:14:34.848054 PST
UTC: 2022-11-25 20:14:34.848054 UTC
However this was probably not a low noise state due to vacuum disruption mentioned here.
I tried following the steps and the method I was using converged to same output matrix upto 2 decimal points but there is still left over cross coupling as you can see in Attachment 1. With the new output matrix, WFS loop can be turned on with full overall gain of 1.
-2. 4.8 -7.3
3.6 3.5 -2.
2. 1. -6.8
3.44 4.22 -7.29
0.75 0.92 -1.59
3.41 4.16 -7.21
Note: The standard deviation on the averages was very high even after averaging for 30s. This data should be averaged after low passing high frequencies but I couldn't find the filter module medm screens for these signals, so I just proceeded with simple averaging of full rate signal using cdsultis avg command.
Fri Nov 25 12:46:31 2022
The WFS loop are unstable again. This could be due to the matrix balancing done while vacuum was disrupted. The above matrix does not work anymore.
I came today to find that PSL shutter was closed. I orginially thought some shimmer obersvations are underway in the quiet state. But that was not the case. When I tried to open the shutter, it closed back again indicating a hard compliance condition making it close. This normally happens when vacuum level is not sufficient, so I opened the vacuum screena dn indeed all gate valves were closed. This most probably happend during this interlock trip. So the main volume was just slowly leaking and reached to milli torr level today.
Lesson for future: Always check vacuum status when interlock trips.
Paco came by to help. We went to asia (the Asus laptop at vacuum workstation) but could not open the medm or find the nfs mounted files. The chiara change did something and nfs mounted directories are not available on asia of c1vac. We rebooted asia and the nfs mount was working again. We can't simply restart c1vac because it runs acromag channels for vacuum system and needs to be done more carefully, a task for Monday.
After restarting asia, we opened the the vacuum control medm screen and followed the vaccum pump down instructions (mainly opening of the gate vales as the pumps were already on). Point to keep in mind, rule of thumb, do not open valve between a turbo pump and a volume if the pressure differential is more than 3 orders of magnitude. Saving turbo pumps is the priority.. Now the main volume is pumping down.
Turned off HEPA at:
PST: 2022-11-25 15:34:55.683645 PST
UTC: 2022-11-25 23:34:55.683645 UTC