As Of 15:26UTC (8:26PT):
Posted below are the plots for the various PSL pressure, flow, and cooling signals post 70W and new shutter install. This should represent the final configuration of the reworked cooling system necessary to accommodate the new amp. Most changes reflected in the plots are as expected and should assist with final tuning and balancing the water flows. The goals of the tuning will be to (1) reduce pressures as much as possible while retaining enough flow to ensure proper cooling. (2) to shift pressure manipulations from within the PSL enclosure to the chiller room, and (3) to reduce water flow table noise to a minimum.
I lowered the temperature set point from 130C to 127C on the CP4 heater controller this evening. The recent TE203 ROC alarms are the result. The remotely displayed controller screen has been, seemingly, unchanging now for days? weeks? so I perturbed it to verify that the displayed temperatures would react/change. I am monitoring periodically.
Kyle and I independently leak checked IP4 gate valve on the beam tube side and found a very delayed He signal (many seconds to minutes). I bagged the flange joint with party store balloon mylar and found minutes delay from a vertex background signal of 4.8e-9 Torr-L/s to a leak rate of 8.5e-9 Torr-L/s, using UL1000 leak checker. It's still unclear if this flange joint is leaking or if He is migrating to the actual leak. Need N2 to flush out the He. After the leak rate crept up to 8.5e-9 Torr-L/s very slowly, I finally removed the bag and then it crept down even slower while I blew on the flanges.
Note that the flanges were somewhat gappy after installation (top and bottom of valve) a few months back. Gerardo torqued them metal to metal and found that the pressure improved on the IP4 pump side (its GV is closed), from April 13th.
IP4 was leak checked after it was installed last year with a small leak noted from 8" CFF: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=40339
The background of the vertex volume is 4.8e-9 Torr-L/s of He, with UL1000 leak checker backing the main turbo and the vertex pressure at 1.9e-6 Torr (after recent vent). When leak checker+turbo are isolated from main volume, the background drops to 1.2e-9 Torr-L/s and when isolated from turbo drops to >>1e-9 Torr-L/s.
IP4 is 20-30 ft from main turbo+leak checker.
Bag the bonnet?
I can try that. I sprayed it and didn't see an immediate response.
EdM, JasonO, JeffK, PeterK, RickS
The water cooling for the output shutter for the 70-W amplifier was plumbed in this morning.
We were then unable to start the laser. The problem was traced to a blown fuse in the control box.
After lots of fault hunting, we finally got the system to the point that the laser would start at about 5:30.
Things seem to be in order now.
We plan to proceed with the PMC swap first thing tomorrow morning.
This afternoon, Cheryl helped me load the newly prepped PUM mass (PEN ITM03) from the air-bake oven and into it's cake tin for the trip to the end station.
It baked in the air bake oven at 34 degC for 12 hours starting last Fri midday.
The code that looks for guardian errors was preventing us from running VerbalAlarms. I've commented this code out of the tests file (around line 109). Will need to be reverted when guardian work is complete.
Activities:
Details:
J. Kissel, T. Shaffer Replacing S/N 551 (bad) with S/N 553 (hopefully good). New open light current value: 29106 OSEMINF OFFSET = -14553 OSEMINF GAIN = 1.0307
Daniel changed some internal wiring in h1sqz. Model was restarted, no DAQ restart needed.
F. Clara, J. Kissel, T. Shaffer We're back at the SUS OPO, trying to solve the last problem -- that the V2 OSEM shows a poor frequency response above its resonances (41256) that appeared between Feb 2018-02-27 and 2018-03-29. Because the poor frequency response has the same shape as the well-known sensor-to-actuator electronics coupling -- high-Q zero at 10-20 Hz -- (a.k.a. high frequency turn-ups a. la IIET Ticket 478040536 and 40613). The below set of tests has convinced us that the H1 SUS OPO V2 AOSEM needs to be replaced, so we'll do that this afternoon. We've therefore conducted several electronics tests this morning: - Ran the standard "ground loop" checks for shorting of the readout-chain's shield to ground: disconnected the H1V1H2V2 DB25 pin cable on the back of the US satamp, plugged a DB25 pin breakout board into the cable, then - Check for any short of pins to chamber ground: - run a lead from the closest chamber (in this we clipped to a bolt on one of the viewport blanks on the HAM5 side of the MCB Output Beam Tube between HAM4 / HAM5) into the Return (black) of the DVM - and check for continuity between any of the 25 pins and chamber ground. - There shouldn't be any continuity, and we found none. - Restoring the standard (black) lead into the Return of the DVM, check that pin 13 is continuous with the shield of the cable, and no other pin is continuous with ground. Only pin 13 should be continuous with the cable shield, that was true. - Check that no pin is unintentionally/unexpected continuous with any other pin. For this OSEM cable fed into a US Satellite Amplifier (D1002818), we expect pins 1 & 14, 4 & 17, 7 & 20, 10 & 23 to have low resistance because these connect the positive to negative legs of the OSEM coil (namely ~19 ohms). However, no other pins should be continuous with each other. We found all this to be true. - Scoured the in-chamber readout cabling, looking for potential electrical grounding between the readout cable and the ISI or chamber walls. We found nothing obviously suspicious, and no change in frequency response after several moves. - TJ physically disconnected the micro-D connector of the Quadropus (D1000239) from V2 OSEM at the OSEM, then re-seated and re-tightened the connection. No change in response. - TJ physically disconnected the DB25 connector of the Quadropus from the Table Cable Bracket (D1001346), then re-seated and re-tighted the connection. - TJ found that one of the screws securing the flexi-circuit (D0901252) to the V2 AOSEM assembly (D0901065) was loose, so he tightened it. After these two changes test, we saw a significant increase in the zero frequency - Further tightening and loosening of the AOSEM's flexi-circuit screws continued to have an effect on the zero frequency, namely tighter made it *better* but not perfect like all other OSEMs. - As a final nail on the coffin of the flexi-circuit of the V2 OSEM, we swapped micro-D connectors of the Quadropus cables between H2 and V2, and readout each the OSEM with the opposing signal chain -- taking a transfer function of V2 with the H2 electronics chain, and of H2 OSEM with the V2 electronics chain. V2's electronics chain reading out H2 showed an entirely normal high-frequency response [first attachment]. H2's electronics reading out V2 showed a similar bad response [second attachment]. Attachment Key: [first attachment] - black : Perfect (in-vacuum), fully functional reference from L1 SUS OPO - magenta : Before today, clearly identified badness (high-frequency zero) with V2 electronics reading out V2 OSEM. - red : Fully functional, today, with V2 electronics reading out H2 OSEM. final nail in the coffin [second attachment] - black : Perfect (in vacuum), fully functional reference from L1 SUS OPO - blue : H2 electronics reading out V2 OSEM Still bad, final nail in the coffin - magenta : Before today, clearly identified badness (high-frequency zero) with V2 electronics reading out V2 OSEM. - red : During today, after tightening flexi-circuit screw.
A significant roll of the ETM optic is apparent in the attached photos, which corresponds to the fibers breaking on one side of the optic. We used the welding mass jack to lift the mass off of the compressed viton EQ stops and to unload the remaining two fibers such that if they are compromised they would not catastrophically break. I would estimate that not more than 1-2 mm was required to fully unload and slacken the remaining fibers, indicating that they were already almost completely unloaded after the break.
The photo of the wipe shows a piece of metal particulate found on the lower structure and gives you an idea of the size and nature of particulate commonly found around the Quad as a result of the assembly/disassembly procedure.
To get h1seiey running again I rebooted it using the front-panel-reset button. This in turn caused a dolphin glitch of h1susey and h1iscey. I rebooted h1iscey because it had an uptime of 211 days, I just restarted all the models on h1susey (it has an uptime of 38 days).
I was hoping to do an OMC scan today and it's tantalizingly close with the angular loops closed but it seems like the both OMC_DC are saturating even though I've turned off the all the gains and whitening(de-whitening). The attachment shows the scans going negative at 2 Watts into the IMC.
So I turned down the power into the IMC to about .1 watts and things got better but it was still very unclean scan data so I'm a little confused because Dan Hoak's OMC scan was able to handle about 4 miliamps on OMC_DCPD Sum.
I've misaligned SR2 so that the OMC isn't flashing and returned the DCPD whitening filters to their nominal observe state (1 whitening + 1 dewhitening). Also I've turned off the OMC ASC and the AS WFS DC loop so that if the IMC loses lock the optics don't go crazy.
I turned down the power to the IMC to .1 Watts and misaligned SRM to get rid of the SRM flashing and there's some decent, clean OMC resonances.
Attached are 3 OMC scans with SR3 at 0, 0.5, and 1.0 Watts. Before I take more data at higher SR3 heater power, I'll see if these results make sense. The columns are time in seconds, PZT offsets in Volts, and OMC_DCPD output in Amps.
Once we lock DRMI, we can try this again.
I've ran your scans through through my code. The plots are attached below. The "mismatch" (i.e. ratio of the average of all second order peaks to the average of all zeroth order peaks) is 0.08 +/- 0.02, 0.09 +/- 0.02, 0.083 +/- 0.005 for 0W, 0.5W, and 1W respectively. The uncertainties came from the standard deviation of the height of the peaks. Most of the uncertainty came from fluctuations in the height of the zeroth order peak. As it stands now I can't really draw any conclusion about the SR3 heater. It could be that the pzt is scanning too quickly, or the beam/cavity could be fluctuating in time. I can't say for sure. There's also this weird thing where the resonances on the upward pzt ramp appear in different locations to the ones on the downward ramp, even though they should correspond to the same length changes in the cavity. Could be some hysteresis in the pzt response. For the analysis I only used downward ramp on the pzt. Driving the pzt with a sawtooth waveform should get rid of hysteresis (since it would only ramp one way), but there might be some artifacts from the sudden voltage change.
