Vicky, Naoki

We aligned pump AOM and fiber. This time, we aligned AOM from front panel without opening the back panel. So this work can be done with local laser harzard.

We set ISS drivepoint at 0V and measured the AOM throughput. The throughput was 40 mW/62 mW = 65%. We aligned AOM to maximize the throughput and got 59.5 mW/62 mW = 96% throughput.

Then we set ISS drivepoint at 5V and aligned AOM to maximize the 1st order beam. The 1st order beam increased from 3.7mW to 9.1mW. However, when we set the ISS drivepoint at 0V, the AOM output was only 40.5mW. This is already reported in 78519. We aligned AOM to maximize the throughput and got 58.7mW of AOM output.

We repeated this alignment several times as follows.

1st order@5V ISS: 15.8 mW, 0th order@0V ISS: 48 mW, 60mW after alignment

1st order@5V ISS: 16.3 mW, 0th order@0V ISS: 52.4 mW, 56mW after alignment

1st order@5V ISS: 15.3 mW, 0th order@0V ISS: 53 mW

We were getting better AOM throughput at 0V ISS while maitaining the reasonable 1st order beam at 5V ISS. We could improve the alignment more, but we stopped here due to time limitation. 

Finally we aligned the pump fiber.

FAMIS 31050

The PMC reflected increase/transmitted decrease in power trend is ongoing. Not much else to note on this week's trends.

A while ago Oli found that some earthquakes cause IMC splitmon saturations, possibly causing locklosses. I asked Daniel this with respect to the tidal system to see if we could improve the offloading some. After some digging we found that some of the gains in the IMC get lowered to -32db at high power, greatly reducing the effective range of the IMC SPLITMON. He and Sheila decided that the best place to recover this gain was during the LASER_NOISE_SUPPRESSION state (575) so Sheila added some code to that state to redistribute some the gain (lines 5778 -5788): 

            self.gain_increase_counter = 0
        if self.counter ==5 and self.timer['wait']:
            if self.gain_increase_counter <7:  #icrease the imc fast gain by this many dB
                #redistribute gain in IMC servo so that we don't saturate splitmon in earth quakes, JW DS SED
                ezca['IMC-REFL_SERVO_IN1GAIN'] -= 1
                ezca['IMC-REFL_SERVO_IN2GAIN'] -= 1
                ezca['IMC-REFL_SERVO_FASTGAIN'] += 1
                time.sleep(0.1)
                self.gain_increase_counter +=1
            else:
                self.counter +=1

We tried running this, but an error in the code broke the lock. That's fixed now, the lines are commented out in ISC_LOCK and we'll try again in some other day.

VACSTAT, the vacuum glitch detection system, is now online after a soft rollout. This is a stand-alone EPICS IOC which monitors vacuum gauge pressures and reports if it has detected a vacuum pressure glitch.

Its overview medm can be launched from the sitemap VE pull down, or from the CDS Overview vacuum section.

The attached image shows the VACSTAT Overview MEDM, the system details MEDM and a trend plot MEDM for one of the pressure gauges.

For each pressure gauge, the system maintains lookback FIFOs of the pressure trends. Currently the system is looking back 60, 300 and 600 seconds. Every 10 seconds, the slopes of the data are calculated using a linear regression algorithm. If the absolute value of a slope exceeds its trip value, a glitch detection is raised.

In addition, the total change in pressure over each trend is calculated (Pdelta = Pmax - Pmin). If the delta pressure exceeds a trip value, a glitch detection is raised.

The trend plots have three rows, one for each of the lookback time. The left column is a live plot which continuously streams. The right column latches if a glitch is detected, stopping when the glitch is at the half-way mark.

If a glitch is detected, cell phone alarms are sent to the vacuum team. In addtion, the VACSTAT block on the CDS Overview MEDM will go RED.

All parameters of the system are defined by a configuration yaml file. I'm in the process of writing the user guide.

[Elenna, Gabriele]

I did another test of the PRCL offset today, mirroring previous tests (76814). The motivation for this test is first the large coherence of DARM with LSC REFL RIN, indicating that we are locked with some offset in PRCL. Next, there is large coherence of PRCL and CHARD Y to DARM, and previous tests have shown some PRCL is coupling through CHARD Y, and that coupling can be reduced by adding a digital offset to PRCL, which counteracts whatever locking offset is present in PRCL.

Once again, a PRCL offset is shown to reduce PRCL/REFL RIN coupling, and PRCL to CHARD Y coupling. The minimum occurs with an offset of about -58 (compare to April's best offset of -62). This coupling indicates an offset somewhere between 25 pm and 50 pm (quoting Gabriele 76810). The digital offset reduces REFL RIN/PRCL coupling by 40 dB. PRCL and LSC REFL RIN coupling plot

The offset reduces the noise in CHARD Y by reducing the PRCL coupling by a factor of 10. PRCL and CHARD Y coupling plot, and noise reduction in CHARD Y, CHARD Y noise

The PRCL to CHARD P coupling does not change, PRCL and CHARD P coupling plot (I was lazy and did not properly label this plot, but each trace is a different offset count similar to the other plots). However, the offset worsens the noise in CHARD P, because the offset effectively changes the amount of HAM1 noise coupling into CHARD P, CHARD P noise. We only checked CHARD P, but it likely changes the noise in INP1 P and PRC2 P as well. With this PRCL offset, I ran a HAM1 FF off time, so we could get data to retune the feedforward. (start: 1409940778, stop: 1409941096).

I think that with this PRCL offset, and with an updated feedforward, we will see some improvement in the low frequency noise. The last time we did this test, we did not check the effect on the feedforward, and this is possibly why the sensitivity did not get better, even though we are seeing the exact same reduction in CHARD Y noise as before.

Overall, we can convince ourselves that this result makes sense because the offset is changing the amount of 00 mode present at the REFL WFS.

We have made no changes yet, but I will fit new feedforward so that we can retest this offset + new HAM1 FF at the next commissioning time.

TJ, Vicky, Naoki, Sheila

Since the vent we haven't fully checked some of the usual offsets and settings that we might need to adjust, I started with some of them this morning. 

I started with stepping the BS camera pitch offset, which I'd started in 79663 but wasn't able to finish at that time because of a lockloss.  We gained a little more than 1 kW of circulating power in the arms by adjusting the offset from 233 to 230, see first attachment, this has been added and loaded in lscparams.  The improvement on POP A + B may be because of an alignment shift, we are probably clipping on both of those.

Went to no squeezing and ran OMC alingment offset scan: went to no squeezing and copied Jennie's dtt template from 78616.  This scan saturated the OMC pitch actuator, so I reduced the OMC ANG Y amplitude from 3 to 1 and restarted the scan at 15:53:07-16:16:29 UTC.  TJ and I noticed that the strange flashing behavoir of the OMC camera was coming and going while this scan was happening. 

Following up on 79719 I used the template sheila.dwyer/OMC/OMC_fringe_wrapping.xml and reduced the amplitude to 600 as Naoki did to adjust the OFI temperature. We found that the fringe wrapping shelf amplitude was reduced by increasing the temperature, we went up to 37.5C and the amplitude of the shelf dropped by a factor 3 (second screenshot attached).  We didn't go hotter than this because we weren't sure how hot we would want to operate.   This change in OFI temperature doesn't seem to have changed the optical gain, shown in the 3rd attachment.  (template in sheila.dwyer/OMC/OMC_fringe_wrapping_after_OFI_repair.xml, ref 38 25C, ref 39 28.5C, 40 29.5C, ref 41 30.5, ref 42 31.5C, ref 42 31.5C, ref 43 32.5C, ref 45 34.5C, ref 46 35.5C, ref 47 36.5C, ref 48 37.5C. )

Vicky, Naoki and I started some alignment scans for 4 squeezer DOF (ZM5+6 P+Y) with different frequencies (similar to the OMC offsets), at 17:10 UTC- 17:34:20 UTC. (We continued OFI temperature adjustments while this was happening). 

Closes FAMIS 26007, last checked alog79895

HAMs:

HAM7, the peak at just under 30Hz has grown

BSCs:

ETMX_ST1, ETMY_ST{1,2} seem a little noiser overall

Lockloss @ 09/09 20:12UTC after nearly 10.5 hours locked. At the time we had not been Observing due to the squeezer having unlocked and the opo iss not wanting to stay locked

Today I ran injections for CHARD and CSOFT Y using the NB injections template. To not mess up the templates, I made sure to get both quiet and injection times. They are saved in the usual couplings folder '/ligo/gitcommon/NoiseBudget/aligoNB/aligoNB/H1/couplings'

We can use these injections as part of the determination of the usefulness of CHARD blends.

Mon Sep 09 08:10:16 2024 INFO: Fill completed in 10min 12secs

Richard caught the tail of the fill on camera, it looked good.

15:31 UTC went out of Observing to start Commissioning

TITLE: 09/09 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 3mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

Currently Observing at 158Mpc and have ben Locked for almost 5 hours. Dust monitors were going off in the Optics lab, but everything else normal.

TITLE: 09/09 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: The range was in the 150s, "PSL_ISS diff power is low" notification was flashing occassionally on DIAG_MAIN. We've been locked for 5:30

21:45 UTC Lockloss

23:05 - 23:30 UTC The violins got a little rung up by either of the locklosses so we had to damp them in OMC_WHITENING for a bit

23:30 UTC Observing

23:43 UTC 12 disconnected chans on CDS overview, NUC33 (cdsws04) froze, I had to physically restart it to get it back. This cleared the dc'd chans as expected.

TITLE: 09/08 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY: Just got into Observing after having waited in OMC_WHITENING for a while damping violins - they seem to have gotten rung up from a lockloss we had from ENGAGE_ASC_FOR_FULL_IFO. This last relocking process went smoothly otherwise, and the lockloss from earlier today was also not complicated, besides needing to wait a good while for ALSY WFS 3 Yaw to converge.
LOG:

14:30UTC Observing and Locked for 16:50hours
15:21 Lockloss after 17:39 hours locked

15:41 Going to run an initial alignment after locking green arms
    - ALS_YARM was sitting in the INITIAL_ALIGNMENT state for a while without starting offloading because WFS_3_Y was taking a while to get under the threshold. I took ALS_YARM to UNLOCKED just in case and then back to INITIAL_ALIGNMENT_OFFLOAD and it converged eventually.
16:36 Initial alignment done, relocking
17:18 NOMINAL_LOW_NOISE
17:21 Observing

21:45 Lockloss
22:16 Lockloss from ENGAGE_ASC_FOR_FULL_IFO
23:30 NOMINAL_LOW_NOISE
23:30 Observing

TITLE: 09/08 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 8mph Gusts, 5mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY:

• We just relocked following the lockloss and are waiting at OMC_WHITENING for the violins to damp
• Low wind and microseism