TITLE: 06/07 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: Tony
SHIFT SUMMARY:

Continuing OFI pointing work:  Undid the pointing from last night and returned to a different pointing.

Other big item was toward the end of the shift when Dave & Gerardo contacted the Control Room regarding pressure glitches seen last night which corresponded with (3) higher power locklosses last night.  (We are no longer at this pointing as noted above though, but this took all the focus of the last hour or so.)
LOG:

• 1510-1930 OFI pointing work begins with single-bounce configuration for H1 (sheila,tj)
• 1515-1538 Optics & Vac Prep lab technical cleaning (karen)
• 1707 SHG work in optics lab all day except for lunch break (terry)
  • 2121 kar meng joining
• 1825-1930 (3) groups of 4th graders from Outlook Elem (cassidy,amber,maggie)
• 1935 Manual Initial Alignment!
• 2030-2054 Locking with lockloss at PREP DC Readout as the PR GAIN slowly dropped and became noisy over about 15sec.
  • Lockloss at LOCKING ALS
  • For next lock, Sheila held at PRMI ASC and touched up POP90 via PRM & BS (DRMI was having issues catching---before these tweaks)
    • Reload of ISC_LOCK to undo a change for LOW NOISE ASC (jennyw)
• 2140 Moving magnetometer in lvea (robert)
• 2215 Gerardo & Dave notified the control room about (3) glithes seen on vacuum pressure sensors which correlated with locklosses last night (.  With this we, we are going to have an ndscope up on a wall TV (nuc31) so we quickly see if there are similar jumps in the future.  Dave said he will post an alog.
  • Dave mentioned he noticed these glitches on nds snapshots on the CDS page (on this LINK there are 1, 7, 30 day trends avail for you to see).
• 2229 At this point, TJ un-did the 25W power-up and took H1 back to 2W on Sheila's request (because of the results Dave/Gerardo shared with us).
• 2235 Took VIOLIN DAMPING to ENGAGE DAMPING 2W (Had noticed the violins have been rung up today).
• 2315 lockloss

Sheila D, Jennie W,  Corey G, TJ S

Yesterday we tried a new SR2&3 alignment combination for hopes of better OFI throughput, but after a hrad fought alignment battle, this alignment proved to not work out (alog78290). This morning we started the process to move back to our SR positions that we have been running for the last month or so.

The process was the same that we have been running: walk SR2 and SR3 in a single dof while trying to not fall off AS_C, AS_B, or AS_A, then correct with picos when unable to stay on the QPDs. Repeat with the another dof. This got us back to our target SR positions, but OM3 and OMC were either saturating or getting close to it. Based on part of Keita's recommendation for how to do this move (alog78297), we moved the OMs and some picos enough to engage the OMC ASC, which controls OM1&3 to steer into the OMC QPDs, then moved OM2 to relieve some of the strain on OM3&C. This required a DOF2TT matrix change as in Keita's alog. Eventually we were able to get all QPDS (AS_{A,B,C} & OMC_{A,B}) to be centered with fairly low drive output on the suspensions.

Corey ran a manual initial alignment and brought SRM back to near where it has been. When relocking we first ran into the DARM offset issue that we have been seeing lately (see alog78273), and I didn't catch it in time. The next time around Sheila put the SCR1 Y offset of in and changed the DARM offset and that was enough for us to lock the OMC and move onto DC readout. We've now heard of some other issues, so we are holding here and not advancing over 2W yet.

J. Kissel,

Yesterday, I built another DB9 "shorting plug," similar to that from LHO:67465 that shorts all DB9 pins to Pin 5 without shorting to the backshell of the DB9 connector -- see pictures in the attached 2024-06-06_SEI-C2_DifferentialChanShortingPlug.pdf. Yes, the internal wiring looks sloppy, but I've confirmed that it functions as desired electrically.

While the IFO was recovering from a routine lock loss, I installed the plug into the open-and-unused "In 25-28" port of the aLIGO HAM-ISI Anti-Aliasing Chassis (D1000269) in U28 of SEI-C2 in the Corner Station CER. See pictures of where in the attached 2024-06-06_SEI-C2_ShortingPlugInstalled.pdf.

These 4 channels are otherise unused channels on the seih23 IO chassis' ADC2, which otherwise houses the HAM3-ISI system's sensors and coil driver readbacks (channels ADC2_24 thru ADC2_27). These channel inputs were originally intended to be for analog copies of the ground STS2 (which are now all T240s), created because in the early 2010s, we didn't yet trust the inter process communication (IPC) system. We don't do this, and honestly never ran the cabling -- we've been successful in mapping all ground analog signals from GND T240s into the seib1 IO chassis, reading them out with h1isiitmy front-end model, and then shipping them to h1seiproc via digital IPC, processing them into a sensor correction signal, and then sending over IPC again to each ISI, including HAM3. 
Note -- the HAM ISI wiring diagram, D1101576, inaccurately portrays what channels are unused on this AA chassis at LHO, so I also took the time to create some "as built" photos of the SEI-C2 rack, which are are now linked from the rack's S-number DCC page, S1301863 and will reach out to Dean/Arnaud to get it updated.

I do so for two reasons:
    - For the future HAM3-HAM2 SPI pathfinder system (E2400121), the pitch / yaw "two-way optical lever" QPD system will be limited by ADC noise, so I want to quantify that noise in the real LIGO IFO system down to as low a frequency as possible. Indeed, this rack, and this ADC is what may be used for the pathfinder -- during the conceptual design review, a suggestion was made to look for spare channels in the SEI system before assuming the SPI needed to buy another ADC card; see M2300216.
    - Given recent DuoTone investigations (LHO:78238 and references therein), these channels might prove as an interesting base-line for "normal" shorted ADC channels, like the shorted channels on the low-noise, 524 kHz ADC from LHO:67465.

The read back channels for these will be
    H1:IOP-SEI_H23_MADC2_TP_CH24    
    H1:IOP-SEI_H23_MADC2_TP_CH25 
    H1:IOP-SEI_H23_MADC2_TP_CH26   
    H1:IOP-SEI_H23_MADC2_TP_CH27  
They've always existed, it's just that the differential inputs are now connected to the well-defined 0V GND reference of the AA chassis (which is connected to the same 0V GND reference for the ADC) -- rather than floating. They're sampled at 65536 Hz and not stored in the frames, so only live studies will be possible.

Stay tuned for measurements.

Fri Jun 07 10:09:48 2024 INFO: Fill completed in 9min 44secs

Travis confimed a good fill curbside.

For FAMIS 26249:
Laser Status:
    NPRO output power is 1.81W (nominal ~2W)
    AMP1 output power is 66.81W (nominal ~70W)
    AMP2 output power is 137.4W (nominal 135-140W)
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 9 days, 20 hr 40 minutes
    Reflected power = 20.94W
    Transmitted power = 106.2W
    PowerSum = 127.2W

FSS:
    It has been locked for 0 days 10 hr and 48 min
    TPD[V] = 0.8227V

ISS:
    The diffracted power is around 2.5%
    Last saturation event was 0 days 10 hours and 48 minutes ago
Possible Issues:
    PMC reflected power is high

TITLE: 06/07 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: n/a
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 11mph Gusts, 8mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY:

H1's been down for roughly the last 10hrs and recovery/troubleshooting issues with H1 continue with Observatory Mode set to COMMISSIONING.  There were dust alarms in the optics lab this morning for a few minutes.  Winds are low and microseism has slowly continued a downward trend to the 50th percentile.

Jenne, TJ, Sheila, Ibrahim

TITLE: 06/07 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: TJ (in name only)
SHIFT SUMMARY:

IFO is in DOWN and staying that way until tomorrow.

The remainder of the H1 EVE Shift and the entirety of the upcoming OWL Shift have been cancelled due to Locking issues with the new OFI configuration.

We have not been able to lock since yesterday's short 2.5 hr lock, ending at roughly 10:30 UTC.

Comissioners were tirelessly testing out a new OFI spot configuration when my shift started and despite their determination, it does not seem to be in a good spot. Jenne and I confirmed that IFO_OUT suspensions do not saturate during powerup but it seems that they tend to do so (only OM2 and OMC) at LASER_NOISE_SUPPRESSION. Thus, we have elected to revert the changes tomorrow morning. Check out alog 78290 for more information on this comissioning work.

LOG:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        

Sheila, Francisco, Louis

We would like to measure the sensing function when the IFO is thermalized, with different DHARD ASC loop gains, to see if we still have the ASC cross coupling impacting the sensing function as we saw back in O3: 50511

Based on the measurement in 77857 we thought we could increase the gain of DHARD P from -30 to -45.  This worked fine, so we also tried increasing the gain of DHARD Y from -40 to -60, we were also stable with both of these gains increased by 50%.  I then increased DHARD Y further stepping up to -80 where we lost lock. 

Gabriele, Sheila

Between the locks on June 3rd and June 4th, our LSC feedforward became mistuned (more dramatically than before).  This might explain most of our range drop this week. We don't know why this happened, there aren't any known changes that occured, other than a stretch of windy days with poor locking.

This morning we were briefly locked in our "post April 24th alignment", and Gabriele walked me though doing the iterative feedforward measurements. 

I've updated the README.txt in userapps/lsc/h1/scripts/feedforward with instructions for the iterative measurement:

go to NLN_CAL_MEAS

To turn off FF:    SRCLFF1 (or MICHFF) to DARM: turn SRCLFF1 (or MICHFF) gain to zero, turn off the FF filter but leave the high pass on, turn off the input to SRCLFF1, set gain to 1. Run excitation with the SRCLFF template

SRCL to DARM: nominal configuration with MICH and SRCL FF on, in NLS_CAL_MEAS. Run the template for SRCL excitation
    
When you measure MICH to DARM you leave everything in nominal condition
When you measure SRCL to DARM you leave everything in nominal condition
When you measure SRCLFF to DARM you leave MICHFF in nominal condition, turn off SRCLFF as aboves
When you measure MICHFF to DARM you leave SRCLFF in nominal condition, turn off MICHFF as above

The measurements are checked in at userapps/lsc/h1/scripts/feedforward

SRCLFF_excitation_ETMYpum_2024_06_06.xml
NoLP_MICHFF_excitation_ETMYpum_June62024.xml
MICH_excitation_June62024.xml
SRCL_excitation_June62024.xml

Jenne, Ibrahim

Trended the net movements of some OM suspensions during powerup from our most recent lock acquisition (2024-06-06 10:21UTC to 2024-06-06 15:56 UTC). This was done during today's comissioning to know whether our new OFI alignment configuration would saturate our IFO Out suspensions during powerup. Therefore, this data is just one reference of how much these suspensions usually move during powerup. For details on the actual OFI move today, refer to alog 78290. I've attached an identical (and prettier) sheets screenshot of the table below.

Sheila, Jenne, TJ, Ryan, Keita, Jennie W

Today we had trouble locking from the start of the commissioning period. This seems to have been a problem with OMC locking - see Ryan's log for further details.

We scanned the OMC in single bounce anmd everything seemed to look ok.

We managed to power up but then eventually lost lock after Sheila measured LSC FF and Robert took some photos at viewports.

Alena had suggested a better spot we could be aligned to on the OFI (second column on second last page), so since we have been having locking problems since maintenance on Tuesday we decided to unlock and try this move.

The best spot suggested is so far off that we know we will have to use the HAM6 picomotors to recentre the beam on the AS_A, AS_B and AS_C QPDs.

TJ and Jenne slowly brought us to this new spot (between two t cursors in this image) while also using picomotors 2X, 3X, 3Y, 1X to keep us centred on AS_A, AS_B and AS_C. During this time we were also trying to run the DC centering loops on OM1 and 2 to keep us centred on AS_A and AS_B, unfortunately we then ended up in a situation where we were saturating OM1, 2 and 3 and OMC suspensions at different points. Turning off the DC centering loops relieved OM1 and 2.

We couldn't get past PREP_DC_READOUT_TRANSITION.

Before doing this, at 22:50 UTC Sheila and I measured the spot positions on the SRM and SR2 mirrors using the A2L gains.

Sheila tried to releive the OMC and OM3 suspensions using their sliders but eventually we realised that we might have to do a combo of this with more pico-motoring to lock the OMC and power up.

This is shown in this image, however, these efforts eventually unlocked us.

Here is another ndscope showing the full days efforts with the ISC_LOCK guardian state also.

Andrei, Naoki, Sheila

Following the research of aLOG 78125 and aLOG 78262, we aimed to quantify the value of backscattering from the ZM2 and ZM5. We performed backscattering measurements under the assumption that modulation of the optical path between scatterer and interferometer would introduce additional noise in the DCPD spectrum [1-4].

We used data from the H1:OMC-DCPD_SUM_OUT_DQ channel (calibrated to mA of photocurrent) for the times of aLOG 78125. We've then calculated RIN with correction for the DARM control loop. Using Eq. 25 from [1], we performed manual fit. Although we couldn’t perfectly fit within the range from 15 Hz to 21 Hz (probably because of the chosen Welch's transform parameters), we were still able to obtain meaningful results for the backscattering coefficients (see Fig. Backscattering_meas.png). The resulting coefficients are below:

r_ZM5 ≈ 4 x 10^-4

r_ZM2 ≈ 0.1 x 10^-4

Also note, that the amplitude of the excitation used for fit is several times larger than that we've measured from the H1:SUS-ZM#_M1_DAMP_L_INMON channel (1.2 μm unstead of 0.4 μm).

Code that was used for this calculation is attached to this report. OM1_fringewrapping_test.m (Sheila's code) was used to calculate RIN, main.nb was used for manual fit and plotting.

[1] Martynov, D. V., Hall, E. D., Abbott, B. P., Abbott, R., Abbott, T. D., Adams, C., ... & McIver, J. (2016). The sensitivity of the Advanced LIGO detectors at the beginning of gravitational wave astronomy. Physical Review D, 93(11), 112004.

[2] Ottaway, D. J., Fritschel, P., & Waldman, S. J. (2012). Impact of upconverted scattered light on advanced interferometric gravitational wave detectors. Optics express, 20(8), 8329-8336.

[3] Nguyen, P., Schofield, R. M. S., Effler, A., Austin, C., Adya, V., Ball, M., ... & Moreno, G. (2021). Environmental noise in advanced LIGO detectors. Classical and Quantum Gravity, 38(14), 145001.

[4] Fricke, T. T. (2011). Homodyne detection for laser-interferometric gravitational wave detectors. Louisiana State University and Agricultural & Mechanical College. 

On Tuesday, I tried running the HAM7 high voltage CPS electronics again. This time I was able to get all 6 sensors to the noise floor I expected. I replace another ethernet cable and one of the in-air triax cables, and I had to use one of the test cards the RichM used at MIT to get there though. After that I was able to turn the isolation loops on let the ISI run for a while when we were trying to lock. My initial measurement looked like the low frequency isolation was pretty bad, so I reverted to the old electronics that afternoon. 

Attached first 3 images compare the performance with the high voltage cps (refs) and the nominal cps (live traces). The high frequency performance is not really any better, and in RX and Y the below .3hz performance seems much worse. Z seems to be worse pretty much everywhere below 10hz. Maybe one of these sensors has a funny calibration or something? I will probably try again next week and see if I can measure that with some ISI tfs.

Fourth image is calibrated spectra for each individual hv cps. The H1 still had a high noise floor for this test. Another thing to try to fix next time.

Jenne D,  Jennie W

Jenne noticed that our AS_A_YAW offset was on in the current state (PREP_FOR_LOCKING). We don't want this offset on currently as we are moving to a different spot on the OFI for which we need the picomotors, therefore we my need to rethink AS_A and B alignment offsets.

We turned this offset and the other AS_A and AS_B oiffsets off.

This is the only one I could find set in the ISC_LOCK guardian so I commented this line out.

        elif self.counter==9 and self.timer['LoopShapeRamp']:
            #ezca['ASC-AS_A_DC_YAW_OFFSET'] = -0.15 J Wright commented this out on 6th June 2024.
            ezca.switch('ASC-AS_A_DC_YAW', 'OFFSET', 'ON')

I reloaded the ISC_LOCK guardian.