OMC Sensing matrix measurement done + ASC converges

Jennie W, Sheila, Matt Todd, Trent Gayer, Craig

Summary: Measured summing of QPDs on OMC and remeasured the sensing matrix and updated the input matrix for the OMC ASC. We also locked the OMC with no sidebands and took an OMC scan. The AS loops look good but we might need to check the summing of the QPDs offline as we weren't sure if the yaw quadrant summing of QPD B has the correct sign.

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First we checked that the quadrants of the two OMC QPDs are summed the correct way.

When OM3 pitch is stepped up, as in image 1:

• the quadrant 1 and 4 increase and 2 and 3 decrease. This is the same for both QPDs.
• Though the A QPD responds more to OM3 than B which should be the correct way round.

Image 2 shows the same thing when we increase the yaw signal on OM3 segment:

• 1 and 2 increase and segment 3 and 4 decrease for QPD A.
• 1 and 2 decrease and segment 3 and 4 increase for QPD B.
• As for pitch the response of QPD A seems slightly less sensitive to OM3 than B which we expect.

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See image 3 and 4 for the original input and output matrices for the OMC ASC before our measurements started today.

We measured the sensing matrix from pitch of OM3 to  pitch and yaw of A and B by moving OM3 up in pitch by 50 counts. See image 5. You can see here that yaw on the QPDs is cross-coupled  to pitch which we ignore for the purposes of this analysis but is good to note.

We measured the sensing matrix from pitch of OMC to  pitch and yaw of A and B by moving OMC up in pitch by 500 counts (as it was hard to see a rerponse for 50). See image 6.

For both we divided the step on the QPD by 50, this might make the matrix coefficients differently scaled but we can fix this later by changing the loop bandwidths if neccessary.

This must be done with the ASC off so the step response can be seen.

Then we inverted this sensing matrix to get the input matrix after zeroing the output values for ANG Y and OM3 and POS Y and OMC sus.

We also have changed the output matrix in pitch to feedback only to feedback to OM3 for POS DOF and OMC only for ANG DOF to simplify the loops. See image 7.

Next we measure the yaw with steps of 50 counts again in the same way. Shown in image 8 and 9.

Then we changed output to decouple yaw drives as for pitch so pos drive only goes to OM3 and ANG drive only to OMC sus.

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Then Craig and Matt had to re-measure the OMC  in yaw as had measured the OMC offset drive wrongly.

The new input matrix after inverting our sensing matrix for yaw and scaliing it by a factor of 50 is shown in image 10.

New output matrix (no value changes, just turned off POS feedback to OMC sus and ANG feedback to OM3) is shown in image 11.

ASC now converges. Image 12 shows it working.

Matt locked the OMC with ASC on shown in image 13.

I've put in a "fake dark offset" OMC DCPD A to make the data from the OMC scans never be less than zero.  This is still engaged at the moment.

Tue CP1 Fill

Tue Mar 05 10:09:27 2024 INFO: Fill completed in 9min 23secs

Gerardo confirmed a good fill curbside.

Slow controls

Fernando, Patrick, Daniel

The slow controls system has been updated to the most recent version that includes the new OpLev motors (ITM/ETM/BS) and a fix for the negative weather station temps. SDFs for corner AUX and ISC have failed and are stuck.

h1cdsh8 front end server replaced

The h1cdsh8 front end server, which was a 14-core ws2275 was replaced with a standard 8-core ws2245. 

The ws2275 is still operational and is on a shelf in the MSR.

PSL Cooling Water pH Test

FAMIS 19971

pH of PSL chiller water was measured to be just above 10.0 according to the color of the test strip.

ISI CPS Noise Spectra Check - Weekly

FAMIS 25981, last checked in alog76035

Spectra of HAM8 looks quite different in lower frequencies compared to last check, but higher frequency noise around ~100Hz looks to be about the same.

All other chambers look nominal, report attached.

DAQ DC0 crash 06:21 this morning

h1daqdc0 crashed at 06:21 this morning. It did not respond to pings, its console was stuck at the login prompt and there were no log entries at this time. DAQ was running with 1-leg only while DC0 was down.

Erik rebooted DC0 which caused the 0-leg to retstart. TW0 started too quickly, had -3 seconds delta start time. I restarted TW0.

Mid station chillers turned off

For those monitoring the chilled water temperatures, the chillers at the mid stations have been shut down due to low loads. They will be turned back on once the season changes and ambient air temps begin to go up. Chiller disabling will be indicated in the temperature trends and does not indicate a problem. 

All SUS Guardians taken to safe.

All SUS Guardians taken to SAFE for the Front End replacements and model restarts.
 

Tuseday Morning Maintenance Day Start

TITLE: 03/05 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 3mph Gusts, 1mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.12 μm/s
QUICK SUMMARY:

DataConcentrator0 (DC0) crashed at 6:22 this morning

Expected work:
Front end replacement
Open Gate valves!
Wind fence work
CP Fill
Guardian reboot
LVEA Cable tray Length measurements

 

Workstations updated

Workstations were updated and rebooted.  This was an OS package update.  Conda packages were not updated.

3-4 vent vacuum diary

The pressures:
HAM7: ~2.3E-7 Torr
HAM8: ~5.1E-7 Torr
Corner: ~7.9E-8 Torr
EX: ~1.9E-8 Torr

Today's activities:
- EX Turbo pump was valved out. The pressure rises, but will be consolidated at ~2.3E-8
- EX further schedule: it will be valved in to the beamtube at 3-5 - GV20 will be opened

- Another corner RGA scan has been taken at the OMC beam: it shows, that now Hydrogen has the highest partial pressure, water is only at the 2nd place
- The controller of IP1, IP2, and IP3, and IP14 (HAM6) was replaced with old style rebuilt controllers, which has higher maximum current, and therefore handles the pumps much better - they are not railing anymore but pumping nicely; but, they are now invisible in CDS - this needs attention very soon
- Corner further schedule: as the pressure is coming down nicely (and the IPs are happy), if everything stays like this, at 3-5 the main GVs (GV5; GV7) can be opened

- HAM8 RGA bakeout is ramped up, now it is baking for a few days
- HAM7 RGA bakeout was done, and a scan was already taken. It shows that the RGA needs more bakeout, and also that the chamber is free from poisonous gases
- So, the HAM7 IP was valved in, hence the huge pressure drop
- Relay tube - HAM7 - HAM8 further schedule: This volume will be valved in to the main volume around Wednesday-Thursday - RV1; FCV1; FCV2; FCV3; FCV4; FCV8; FCV9 will be opened

Ops Day Shift Summary

TITLE: 03/04 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Main activities today involved OMC scans and background SQZ work as the arm gate valves will not open until tomorrow at the earliest.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
23:29	SAF	LASER SAFE	LVEA	-	The LVEA is LASER SAFE	03:14
16:00	FAC	Kim, Karen	FCES	-	Technical cleaning	16:29
16:20	VAC	Jordan	LVEA	-	HAM7 RGA	16:24
16:42	SQZ	Nutsinee	LVEA	-	CLF measurements at SQZ racks	18:23
16:47	SQZ	Fil	FCES	-	Reconnecting SQZT8	17:52
17:12	SEI	Jim	Remote	-	Working on SEI HAM8	19:02
17:24	FAC	Kim, Karen	LVEA	-	Technical cleaning	18:18
17:31	ISC	Camilla, Matt, Trent	EX	-	Turning on ALSX laser	18:05
17:32	SUS	Rahul	CR	-	HAM6 SUSs transfer functions	18:23
17:43	ISC	Sheila, Georgia, Jennie	LVEA	-	Turning off sidebands	17:52
17:49	CDS	Fernando	EX, EY	-	Oplev grounding work	19:43
17:54	CDS	Fil	EX	-	Checking ring heater power supply	18:54
18:14	VAC	Jordan	FCES	-	HAM8 RGA temp adjust	18:43
18:14	FAC	Karen	EY	-	Technical cleaning	19:06
18:24	SUS	Rahul	CR	-	HAM7 SUSs transfer functions	19:20
18:35	FAC	Chris	Outbuildings	-	Safety checks	20:02
18:53	FAC	Eric	LVEA	-	Checking doors	19:29
20:10	VAC	Janos	LVEA	-	Checking on pumps	21:23
20:10	VAC	Jordan	LVEA	-	HAM7 RGA	20:18
21:28	FAC	Randy	EY	-	Inventory	22:40
21:30	FAC	Chris	LVEA	-	Safety checks	21:51
21:34	VAC	Jordan	LVEA	-	Output tube (HAM4) RGA	21:55
21:38	SQZ	Nutsinee, Daniel	LVEA	-	SQZ racks	22:40
21:39	VAC	Travis	EX	-	Valve out turbopump, cleanup	22:10
22:10	VAC	Travis	MY	-	Dropping off equipment	22:28
22:59	VAC	Jordan	LVEA	-	HAM7 RGA	23:43
23:12	SQZ	Camilla, Julian, Trent, Georgia	Optics Lab	LOCAL	SHG work	Ongoing
23:40	PCAL	Tony, Francisco	PCal Lab	LOCAL	PCal measurements	23:48
23:52	VAC	Jordan. Gerardo	LVEA	-	Opening HAM7 ion pump	Ongoing

OMC SUS kept saturating when we turn on OMC ASC because GRD flipped signs

Jennie W, Sheila, Elenna, Georgia, Ryan S.

Even though Georgia and Trever successfully had the OMC ASC working yesterday before they took OMC scans we have again had problems with the ASC today. We don't fully understand why this is as we had tweaked the alignment on Friday in order to ensure the OMC ASC converged without saturating any suspensions.

We turned on the OMC guardian and it complained about no light on the OMC DCPDs.

We turned on DC centering and SR2 loop and then tried to turn on OMC ASC but it saturated the OMC suspension - this may have been because OMC QPD A was completely off the PD. After we turned off the ASC the beamns were centred again on QPD A and B for the OMC but turning on the ASC still staurates OMC suspension.

Tried turning this on again with SR2 loop off and this still happens.

Same with DC centering loops off.

See first attached image of the ASC loops running away.

In the commissioning meeting it was pointed out that the GRD OMC node might have flipped the POS X and ANG Y gains back to the nominal sign which we had changed last week to make the ASC converge.

Elenna and Matt trended the gains and found that this does indeed happen and flipped them back. After discussions with Ryan we note these gains are hard coded into the guardian so we may need to change this is in the code before the run starts but for OMC scans we will just set these manually and also not accept them in SDF yet.

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Sheila accepted the change to the QPD pitch and yaw offsets we made last week. That is we switched them off. See second image.

OMC ASC Signs Flipped

Matthew Todd, Elenna Capote

Elenna trended the pos and ang gains of the OMC_ASC back in time, and noticed a few hours ago that the signs of pos-x and ang-y were flipped, which we think corresponds to a time when the OMC Guardian was engaged. We corrected the gain signs in pos-x and ang-y (+, and -,) respectively. We are choosing not to SDF this change at this time.

Turning off the 9, 45, 118 MHz sidebands

We turned off the 9, 45 and 118 MHz sidebands at the rack beside the PSL enclosure.

This was to hopefully do OMC scans with no sidebands on at some time this week.

Attached are photos featuring Sheila and Georgia showing where to turn off the 9 and 45 MHz in the electronics rack on the opposite side of the PSL enclosure from the main entrance door.

You have to turn off these two amplifiers.

The second photo shows where to unplug the cable for the 118 MHz at the bottom of the rack.

Sheila, Trent, and Matt

We turned the 9, 45, and 118MHz sidebands back on, and plan to rescan the OMC with these on.

TCS CO2X laser work summary of last few days - final plumbing, laser on, alignment, calibration

This log goes into more detail from yesterday's work (alog75754) and what Jason and I did today.

After we checked the chiller lines had no leaks without the table in loop, we added the tables in next. The Y table was free of leaks, but the X table had a slow drip from a few od the push to connect fittings on the RF driver (attachment 1). We swapped all of these fittings for new ones and cut the 1/4" diameter tubes ~0.5", with a cutter that we borrowed from PSL, for fresh connections. This worked great and there were no more leaks.

To fire up the laser to wanted to avoid the fried opamps that we've had in the past, so we turned on the CO2X electronics in this order:

1. TCSX HV power supply - CER mezz
2. X & Y RF source - mech room mezz
3. X & Y power supplies - mech room mezz
4. X & Y AA chassis - CER
5. X & Y control box - rack by tables

No fried opamps this way. When we turned the newly refurbished laser on, it output 53W according to our Thorlabs S322C power head placed just after M1. The alignment was far off in yaw, not even hitting POL1. Jason and I first yawed the laser itself within its mounting bolt holes, which didn't move much, then started to align downstream. We eventually got the beam to the irises before the periscope, but had moved a large majority of the optics along the way - M1, ISSPO, PM1, PM2, M4, M5, M6 (table drawing). Using the FLIR One camera we got the beam to hit the irises in a similar way to before the laser swap (before, iris1 now, iris2 now). We then checked on the table FLIR for mask alignment. Here we noticed that the annular mask was a little off horizontally, so we translated the mask to better match the previous position (before, annular now). Once we inject into vacuum we might need to make some more minor changes on table, but this looks good for now.

The last steps today were to recalibrate the thermopile at the laser head and verify that the power meter is still centered on the beam. The power meter need a small translation to center the beam. The gain in the laser head WATTS filter was previously 8.58755 and we eventually ended up at 13.904. Jason used new_gain=old_gain*P_m /P_E , where P_m is power measured with the Thorlabs S322C just after M1 and P_E is the power reported in Epics with the old calibration. We iterated this a few times to make sure it was as close as we could feasibly get.

Next steps are to inject the beam into vacuum and check centering with the HWS. The plan is for this to be done just before commissioning starts in a few weeks.

We left the CO2X laser keyed off and ready for the upcoming laser safe work.