Richard M, Dave B, Fil C, Peter K, Marc P.

WP7226

This morning we completed an investigation of the Bullseye PD signal chain.  It was determined that the ISC250 cable position in AA Chassis S1102766 was incorrectly placed one space to the left and should be attached to (IN 29-32).  This was likely overlooked when these chassis were rearranged to make space for squeezer electronics on November 2nd, .  The cable was moved to the correct position and we verified that the signals are received by the ADC.

This morning I completed the weekly PSL FAMIS tasks.

HPO Pump Diode Current Adjust (FAMIS 8449)

With the ISS OFF, I adjusted the operating current of the HPO DBs.  The changes are summarized in the below table and a screenshot of the PSL Beckhoff main screen is attached for future reference.

This is a large increase for just one week of operation, which can be an indication of a DB nearing the end of its life (remember that DB2, DB3, and DB4 are still the original DBs installed when the H1 PSL was in late 2011/early 2012).  We will keep an eye on this.

I did not adjust the operating temps of the DBs.  The HPO is outputting ~154.0 W and the ISS is back ON.  This completes FAMIS 8449.

PSL Power Watchdog Reset (FAMIS 3920)

I reset both PSL power watchdogs at 17:18 UTC (9:18 PST).  This completes FAMIS 3920.

   Posted below are the 45 day trends for the HEPI pumps. Most plots look reasonable for being in a vent status. The CH6 HPI-PUMP_EX_PS_PRESS signal drops to <0 at 19:02 (11:02PT) on 11/08/2017. This may be due to the HEPI control channels being migrated to Beckhoff.   

(Keita K, Jeff K, Gerardo M)

After centering the beam on SRM the OFI position was way off with respect to the beam, so the cage was moved until the beam made it all the way to HAM6, the beam position is satisfactory on YAW, however the position is off in PITCH at the input of the OFI, fine tuning to continue tomorrow.

1. SRM beam position was off last week by about 3/8 inch.

When the beam is properly centered on SRM, the beam position on SRM is about 3/8" towards -X than we thought last week.

Beam centering on SRM horizontally is almost impossible to do by looking from outside HAM5, and instead it seems as if this was done in the past week by centering on the baffle hole on the back of the SRM.

Today we sent JeffK into the tube between HAM5 and HAM4 and have him look at the beam on SRM while I was holding the card right in front of the SRM. Doing it this way, it turns out that the beam is about 3/8" inch off centered on the back baffle hole in -X direction.

My guess is that the  original centering was not done from the front of the SRM. I also wonder if the cage position itself is off.

TJ repositioned the baffle so the beam is centered on the back baffle, and Gerardo moved OFI such that the beam at least clears the OFI (he'll fine tune tomorrow).

2. Septum window was rotated by 120 degrees counter-clockwise and the beam was great in PIT, but of course not great in YAW.

Gerardo and Travis rotated the septum plate by 120 degrees counter-clockwise so that the beam height becomes good on OM1.

The thickest side went to South, which moved the beam further in -X direction.

The beam was blocked by the fast shutter. When I moved FS to the side, the beam was hitting somewhat to the -X side of OM1 -X damping plate adjuster screw, meaning the height was right but it was off to the side by about 36mm in -X direction.

Table below shows Koji's measurement of beam position on OM1 last week (alog 39460), beam position changes which should have been caused by septum rotation assuming that the wedge angle is 0.89 deg (measured by Koji, instead of 0.75 deg derived from the thickness measurement) (alog 13399), and the beam position measured today. If everything is right "in theory" and "measured" columns should agree. At least they don't look totally wrong.

3. Rotating Septum by 180 degrees will bring the beam to a better position

Assuming that SRM is/was at the correct location (we need to check), the next question is what to do.

Unfortunately, I cannot simply move OM1 and be done with that, it seems like the beam from OM1 to OM2 will be either blocked by OM3 or very close to it. I can move OM2 but that will leave no room for the fast shutter as the OM1-OM2 will be much closer to OM2-OM3 line than before.

We can rotate the septum window by 180 degrees so the thickest side comes to the north. Assuming 0.89 deg wedge, the beam deflection is 7 mrad, so 180 deg rotation will give us 14mrad change in deflection.

The distance from the septum to OM1 is 1930mm, so this will result in the horizontal shift of 27mm  without height change. The beam will be at X=-36+27 = -9mm on OM1 horizontally. Hopefully this will allow us to make room for the fast shutter without moving OM2 sideways.

Laser Status:
SysStat is good
Front End Power is 35.8W (should be around 30 W)
HPO Output Power is 151.5W
Front End Watch is GREEN
HPO Watch is GREEN

PMC:
It has been locked 2 days, 7 hr 43 minutes (should be days/weeks)
Reflected power = 25.37Watts
Transmitted power = 48.21Watts
PowerSum = 73.58Watts.

FSS:
It has been locked for 2 days 7 hr and 43 min (should be days/weeks)
TPD[V] = 2.039V (min 0.9V)

ISS:
The diffracted power is around 1.6% (should be 3-5%)
Last saturation event was 2 days 7 hours and 43 minutes ago (should be days/weeks)

Possible Issues:
PMC reflected power is high
ISS diffracted power is Low

Jeff B and Dave:

Jeff inherited a very red looking CDS overview screen this morning (see attached) which was not being auto-cleared.

Digging deeper, the h1lsc0 user models TIME glitched at 06:56 PST this morning, but the h1ioplsc0 model did not. This is the first time this has happened, the normal glitch behaviour is an IOP glitch with optionally an accompanying user model glitch. My auto-diag-reset script only looks for LSC-IOP glitches, and therefore did not clear this one.

If we see an overview similar to the attached one, please alog it and then press the "! Diag Reset" button on the bottom of the CDS overview screen to clear the errors.

I switched the cables for the PSL table temperature signals, H1:PSL-ENV_LASERRM_TBLS_TEMP_DEGF (table south) and H1:PSL-ENV_LASERRM_TBLN_TEMP_DEGF
(table north) at the back of the PSL environmental chassis.  This corrects the north/south identity problem.  So now the signal labelled TBLN
really is the "north" end of the table, as per the documentation.

Noticed the Corner3 CPS readings were both railed at -23k -32k and the Near Limit light was illuminated on the CPS Satellite box.  I trace this back to the point in time that the ISI was being locked and the Corner3 Feedthru was being reworked back in early October.  For the vertical sensors, the rail cleared when the exterior copper shield was cleared from the BNC bayonet which is used in the circuitry.  The Horizontal would not yield so easily.  On the vacuum side the Horizontal reading would clear if the cable inside was mucked with but it was not satisfying to this troubleshooter.  It seems this corner of cables need serious reworking.

Work plan for week of 11/20-2017

HAM2: Zero out bias sliders
	   IM4 trans alignment 

HAM3/4: Baffle alignment
	     Torque SR2
	     B&K Hammering
	     MC2 alignment and By-Pass work

HAM5: Adjust/mod height of spacers
	    Align OFI, ZM1-6, OM1, OM2, and SRM
	    Septum Window 
	    B&K Hammering
	    SMR alignment

BSCs: Baffle alignment 
	   Chamber closeout tasks

The BRS-X needs to be recentered

VAC: Vacuum group asked to be informed of all changes to Purge Air. Any changes should be communicated through the operator. 
	  

Nothing besides the trending "unusuals" to report other than curious looking oscillations in OSC_DB4_PWR that appear to correlate to the temp issues and don't seem to be as prominent in 1-3.

Topped up the crystal chiller with 250 ml.

I have added new features to the element lal_resample used in the gstlal calibration pipeline so that it can perform upsampling for the actuation equal in quality to the old gstreamer (version 1.4.5) resampler. The upgrade to gsteramer-1.10.4 on the clusters introduced a ~2% systematic error in the C01 frames from ~50 Hz to ~1 kHz during the month of August. See, e.g.,
https://ldas-jobs.ligo.caltech.edu/~alexander.urban/O2/calibration/C00_vs_C01/H1/day/20170802/

The change made was the addition of a sinc table filter in the upsampling routine. Several tests were done, and plots are attached:

The first two plots show the filter's response to a series of impulses separated by 4 seconds. This input data was upsampled from 128 Hz to 1024 Hz. The first of these plots shows 30 seconds of data, and the second is a close-up on a single impulse.
The 3rd plot is a 10-second sinusoid upsampled from 8192 Hz to 16384 Hz.
The 4th plot is a 30-second stream of ones upsampled from 128 Hz to 1024 Hz. The apparent thickness of the line indicates the amount of digital error, of order ~10^-8.
The 5th and 7th plots are ASD comparisons between the output produced by the calibration pipeline using this new resampler and the C00 frames from August.
The 6th and 8th plots are ASD comparisons between the output produced by the calibration pipeline using this new resampler and output pruduced with no resampling at all (i.e., all actuation was filtered at 16384 Hz). I suspect the wiggle above 1 kHz is due to a ~2% contribution from the actuation that is lost in downsampling to 2 kHz for the filtering.

For information on filters to be used for C02 production, see
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=39419
https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=36707

TJ, Sheila

This morning/afternoon we ( Keita, Jeff K, TJ, me, Lisa, Alvaro and Calum) realized that the riser for ZM2 (the squeezing TT in HAM5) is too tall, since it is set to match the height difference between HAM 5+ HAM6 at L1, which is not the same at H1.  

TJ and I went to the chamber to make some sanity checks that the discrepancy is about what we should expect based on drawings. We first set up a laser pointed that was mounted on a small breadboard in the cleanroom by HAM3 in the back of HAM6, pointing towards HAM5.  We leveled this by measuing the distance of the beam off the table near the laser pointer and again at the far edge of HAM6, roughly a meter away.  With our final tin foil adjustment we got the beam parallel to the table to within a mm over this distance.  The laser beam was 99 mm off of the HAM6 table top, and 203 off of the HAM5 table top, so we estimate the difference this way to be 104mm, or 4.1 inches.  

We also measured the height of the center of the ZM2 mirror to be 223 mm off of HAM5, or 8.78 inches.  That means that the center of ZM2 is 8.78-4.1 = 4.69 inches above the level of HAM6, them beam height in HAM6 is 4 inches.  Calum looked at drawings earlier and said that the riser height should be 0.76 inches too tall for H1 if it is based on L1 heights. 

We also attempted to measure the height of the center of the output aperture of the OFI off HAM5, which was a little difficult with our too short ruler and an akward angle.  We measured 3 times and got 207.5 mm, 205 mm, and 209.5mm.  (8.16 inches average, so 0.617 inches below ZM2).  

It seems like these measurements are in agreement with what Calum found in the drawings, within the precision of this measurement technique. 

S Cooper, J Warner

We've been investigating the reasons into why HEPI tripped during O2 to see if anything could be done to prevent it. To do this we've been looking at both the time series sensor data in the local basis (H1,H2,V1,V2 etc), for the IPS, STS, L4C's and Actuators, the saturation counts and the watchdog status for every chamber (BSC's and HAM's - with the exception of HAM1). The first earthquake we ran this on was the Montana earthquake (GPS 118335800) as this was the only earthquake where HEPI was the first to trip.

When we if we look at the saturation counts, we find that only the L4C's are hitting their saturation threshold and are therefore likely causing watchdog trips, the horizontal L4C's are the first to saturate. 

If we then compare the levels that the watchdogs trip at across all 10 chambers, we find that ETMX trips at 10% the level of the other chambers. I've attached an annotated PNG highlighting the BSC chambers, and a .fig file that contains the saturation data for all 10 chambers. The dashed lines indicate the watchdog level (multiplied by 10,000 for easier comparison) with the solid lines indicating the specific chambers L4C. 

I'm now running the same script for other earthquakes that HEPI tripped in to see if this is an isolated case. 

[Maddie W., Aaron V., Greg M.]

Here is a summary of the filters and command line arguments that should be used for the C02 frame generation using the DCS calibration pipeline.  This information is compiled from configurations wiki page and aLOGs linked from that wiki page.  The command line arguments should be the same as for C01 except for changes noted in the table below.  (Additionally, the frame names and channel names should be changed appropriately to C02.)

--expected-fcc=347.2
--coherence-uncertainty-threshold=0.004
--wings=(something larger than 600)
--no-fs 
--no-srcQ
--update-fcc
--fcc-averaging-time=600
--fcc-filter-taper-length=32768
--pcal-channel-name CAL-PCALY_TX_PD_OUT_DQ

--expected-fcc=360.0
--coherence-uncertainty-threshold=0.004
--wings=(something larger than 600)
--no-fs
--no-srcQ
--update-fcc
--fcc-averaging-time=600
--fcc-filter-taper-length=32768
--pcal-channel-name CAL-PCALY_TX_PD_OUT_DQ

--expected-fcc=360.0
--coherence-uncertainty-threshold=0.004 
--wings=(something larger than 600)
--update-fcc
--fcc-averaging-time=600
--fcc-filter-taper-length=32768
--pcal-channel-name CAL-PCALY_TX_PD_OUT_DQ