Following on alog 45653 and FRS 11921/10987 went down to EX to troubleshoot.

1. Power cycled PCAL chassis, temperature readbacks still glitchy.
2. Disconnected both the Transmitter and Receiver temperature sensors. Readbacks showing 0 counts.
3. Two spare AD590 sensors connected. Readbacks signals still glitchy.
4. Unit was brought back to EE lab. Output of chassis for temperature sensors both stable.
5. Unit was returned to End X.
6. Used 2 voltage calibrators and injected to Beckhoff, both readback signals stable.
7. Reinstalled cabling and power back up. Accidently connected shutter to temperature readback port causing the +15V to dim on front panel.
8. Power down and corrected cabling, power back on, tested shutter locally.
9. Both temperature sensors showing valid temperatures.

F. Clara, P. King

This morning I swapped a couple of OpLev Lasers around the site. I took the less glitchy lasers from SR3 and PR3 and replaced the end station lasers that have been very glitchy and vice-versa. All centering remained nominally intact. There was a gain adjustment necessary for SR3. The gain setting was +3dB and it was changed to 0dB. This brought the sum count from ~40K to ~28K. After temperature stabilization, spectrograms will be checked, and if needed, power adjustments will be made to quiet down any "new" glitching.

Unrelated to this swap,  ITMX OpLev, is showing an increase in sum by a factor of 4 (post vent). This remains a mystery until I can go and try effecting a change by a direct power adjustment and/or checking/correcting gain settings at the whitening chassis. Nothing was directly done with this unit directly prior to or after the vent. It is very unusual.

J. Oberling, R. Schofield

At Robert's request I lowered the flow rates of the PSL cooling circuits by ever so slightly opening the bypass valve in the chiller room.  Our target was to get the flows close to 1.5 lpm.  In the past, the flow meters were happy with flows at this level (unlike when we were running with a flow closer to 1.0 lpm and the meters became very glitchy).  Robert will assess how this small change effects PSL table motion; I will keep an eye on the flow meter readings to see if they become glitchy again.

Flow rates before change:

• 35W FE: 1.7 lpm
• 70W Amp: 2.2 lpm
• Power Meter: 1.7 lpm

Flow rates after change:

• 35W FE: 1.5 lpm
• 70W Amp: 1.7 lpm
• Power Meter: 1.5 lpm

The smooth limiter at the input of all of our ASC loops now ramps the input offset, and also ramps the limiter.  So, if you need to change the limit while the limiter is on, it'll ramp - this is an all new feature for gravitational wave interferometry!

WP7929 ISI BSC Senscor Fader

Jim W, T. J., Dave:

New models for h1isi[etmx, etmy, itmx, itmy, bs] and h1seiproc were installed. DAQ restart was needed.

WP7972  mode cleaner M3 lock-loss trigger

Patrick, Dave:

new h1susmc[1,3] models were installed. DAQ restart was needed.

WP7979 ASC smooth limiter ramp

Jenne, Dave:

New h1asc model was installed. DAQ restart was needed

WP7976 h1oaf1 Dolphin Card Relocation

Dave:

h1oaf1 was powered down to relocate its IXH611 Dolphin PCIe card from slot2 to slot3 for consistency with all other front ends. Jeff updated h1calcs's SDF before the shutdown.

DAQ Restarts:

Dave:

DAQ was restarted twice:

08:44 PST for h1susmc[1,3] and h1isi[etmx, etmy, itmx, itmy, bs] model changes

11:21 PST for h1seiproc and h1asc model changes.

No Beckhoff changes this week.

WP7978 GDS low latency frame size modification

Greg, TEAM-GDS:

The production GDS software is being changed to reduce the size of the HofT low latency frame from 4S to 1S.

Dan B. , Danny V.  

• The first time powering up to 30 W the  ITMX Hartmann beam profile seemed resonable and showed a semi-circular profile.
• Next two lock sequences, the ITMX HWS was outputting nonsense. We were convinced that this could be attributed to the new ifo alignment but after heavy picoing we didn't have much luck.
• We checked the ITMX Hartmann beam with both Hartmann plate and 1064 nm notch 800 nm bandpass filter removed and adjusted the picomotors to co-align stray 1064 light and ALS to the SLED beam. (please see the images 3-5)
• After witnessing some fringing in the Hartmann images, which we have previously attributed to stray 1064 light passing through an on-table beamsplitter (alog 45022,alog 45074), we suspected that the current 1064 notch filter 800 nm bandpass in place may be leaking some IR light to the ITMX Hartmann sensor. In response, we placed the 1064 filter as well as the 800nm bandpass filter from ITMY HWS 1064 filter from the ITMY HWS path in the ITMX HWS beam path in series with the 800 nm bandpass. The last attached image shows the state of the ITMX Hartmann sensor after these changes. 
• I'm not convinced that the result is much better than the first 30 W power up of the day.
• Investigations on what happened to the SLED beams after this first power up are pending. 

- To power to 30W, we turned off the 'BOOSTS' (FM5 in DHARD P&Y and FM3 in CHARD P, labeled 'boost10W').

- Turned ISS 2nd loop off and back on with AC coupling (ISS_ON).

- Stepped up to 30W nominal  lownoise configuration.

- Stepped up the RP compensation gains to 1.6 at 30W (same sign as ASC control)

- We lost it on a simple SRC ASC yaw runaway (most likely SRC1 Y).

- We got a good range reading (with good calibration lines) at 25W - 85Mpc.

After Fil and I swapped the REFL_B cable (alog 45652) I connected LSC-EXTRA_AO_2_EXC to IFO REFL CM board EXC and injected frequency noise in ENGAGE_DC_VIOLIN (2W) to see the demod phase of REFL_B and REFL_A.

First attachment shows the Q/I ratio obtained from the frequency noise scan. Top right shows the demod phase "error" obtained by p=atan(Q/I). Apparently REFL_A demod phase is decent, REFL_B is not terrible but could be improved.

Demod phase error should be flat but it isn't, it seems to cross zero at around 100Hz for REFL_A (maybe the demod phase was set using 100Hz excitation?). HOM or something else, regardless of the cause, this seems to mean that if we optimize the demod phase at f>300Hz there's some I-Q mixing in f<80Hz or so, and vice versa. Since I don't see any real Q signal for f>300Hz but there seems to be some junk for f<100Hz (second attachment), we might be better off optimizing at low frequency.

Not too much low frequency coherence between REFL_A and B, it's not clear if this comes from demod phase difference. Since we're not using REFL_B for control, from this point on we could rotate B phase digitally.

It's also worth measuring this at high power.

Jenne, Hang, Sheila, Stefan

• This morning Jenne and Hang tried to use the alignment offsets set for 30Watts at 2W, and saw that the recycling gain was ~38 with those offsets at 2W.
• We then tried to revert the offsets to what we had before the vent, but saw the CSOFT instability when we started to increase the power.
• We have continued to have difficulties with the OMC alignment controls saturating.  This is not likely to be due to the HAM6 HPI being locked, because it is only 10-20 urad away from it's unlocked position, and because the beam is centered on AS_A and AS_B using OMs. 
• People were very enthusiastic about increasing the power, so we agreed to increase the power today and spend tomorrow after maintence on low noise locking at 20-25W. 
• We have been loosing lock due to an instability which seems similar to what is described here: 43968  Jenne and Stefan widened the notches mentioned in that alog, but the problem is still occurring at slightly lower frequency.
• We have had instabilities when powering up due to the SRC pitch loops.  This is new today, and is happening even when powering up to 20W, which had not been a problem before. 

ITMY mode 8 used to be damped using - gain and no phase shift, now it is damped with positive gain and no phase shift. 

ITMX mode 9 used to be damped using no phase and + gain, now it is no phase and -gain.  These changes are in gaurdian.  

All of the changes that we have had to violin mode phases are on the ITMs, which makes me wonder if it is possible that changing the ring heater settings could change something about the violins.  

Not sure the last time someone tried to run an ASC sensing matrix measurement, but it looks like the script didn't properly turn off the 8Hz notches in the DC centering loops.  I've turned them off.

J Kissel, N. Lecoeuche

While glancing at the PCAL END station overview screens, we noticed that the PCALX screen words "STATUS" and "Pcal modules are not powered" were blinking rapidly. The channels that this status indicator are measuring are:
    "Pcal modules are not powered"
        H1:CAL-PCALX_LASERENABLE 
        H1:CAL-PCALX_LASERPOWERCONTROL 
        H1:CAL-PCALX_SHUTTERSTATUS  
        H1:CAL-PCALX_LASERDIODECURRENT
    "STATUS"
        H1:CAL-PCALX_TRANSMITTERMODULETEMPERATURE 
        H1:CAL-PCALX_RECEIVERMODULETEMPERATURE

While the "Pcal modules are not powered" channels are flat and unchanging -- and the same as PCALY -- we found that the "STATUS" channels, i.e. the temperature sensor channels, were reporting a wildly oscillating temperature from 0 to 20 deg Celsius, with a ~1 sec period. 

This junk has apparently been happening since Sunday Nov 11 2018 (~a month ago) at 23:38:56 UTC (Nov 11 2018 15:38:56 PST).

Attached are screenshots of when the failure happened, and how the sensor outputs currently look.

Tomorrow there will be a big update to the BSC-ISI and SEIPROC models. This is mostly to get code to smoothly ramp between different sensor correction filters and get the ground common mode signals into the ISIs. The former should make it smoother to switch between different seismic configurations. The latter is an attempt to improve isolation and reduce drives during earthquakes, something seismic group has talked about for a while.

Part of this update will include a simplification to how the ground sensor calibration and distribution is done. Currently all of the corner ISIs receive the 3 STS2s from a distribution chassis, and each chamber applies the same calibrations on all 9 channels. The update will use the ITMY ISI to send the uncalibrated signals to the SEIPROC model, which will do the calibration, then send that calibrated signal back out the ISIs. SEIPROC will also take over the BLRMS channel calculations.

I'm documenting what I had to do for the corner station ISIs here.

First screen shot, for ITMY I removed and the top level ground block which did the calculation of the ISI-GND_STS_HAM2/HAM5/ITMY calibrated STS channels. This block got moved to SEIPROC.

Second screenshot is the update to ITMY ground in. The green STS tag connect the adc inputs through a bus to IPC channels, of the form H1:ISI-ITMY_A_GND_X_IPC_PCIE, these go out to the SEIPROC model. The calibrated IPCs come in to the STS_CAL tag, the common mode signals come in on the CM_GND tag. Current all of the BSC models are set up to just use the ITMY STS (connected to the STS_CAL tag), but it might be a good idea to use some version of the current STS sensing matrix so that we can change which STS we use for feed forward on the fly by changing an epics variable. Both the STS_CAL tag and CM_GND go into the master model to the  h1isiitmy ITMY ST1 SENSCOR DOF block, contents shown in the third screen shot. This uses the code outlined in T1800414. There is also a new isi master part, the inputs are mostly the same, but there are fewer outputs because there is now need to ouptut the STS signals on the top level.

Fourth screenshot shows the uncalibrated IPC channels coming into the SEIPROC model, fifth shows the new, topnamed ISI block for the generation of the calibrated ground signals. This preserves the ISI-GND_STS channel names, so should not affect anyone who uses these channels. The signals are calibrated using mostly the same stuff that the ITMY model used, and include the BLRMS calculations, shown in the sixth screenshot. I will probably have to make a new MEDM to access the STS calibrations, though.

This update also applies to the endstations, but the STS calibration is done in a block added to the top level. I added this block a couple weeks ago, which required deleting a block like ITMY and stuff on the top level for the BRS subtraction, then wiring up a new block that organized it all in a library part. This change is shown in the seventh screenshot. The endstation ISIs are also getting the common mode signals from the corner.