I tweaked the text on the HTTS screens to correctly reflect the fact that (unlike all other SUS and non-SUS suspensions) the HTTSs have 16-bit DACs.

/opt/rtcds/userapps/release/sus/common/medm/hsss/SUS_CUST_OM_OVERVIEW_ALL.adl

/opt/rtcds/userapps/release/sus/common/medm/hsss/SUS_CUST_RM_OVERVIEW_ALL.adl

/opt/rtcds/userapps/release/sus/common/medm/hsss/SUS_CUST_HSSS_OVERVIEW.adl

(The third screen is common to HAUX so it now says "18 bit DAC (16 for HTTS)".)

The updated screens have been committed and can be svn upped to LLO at any convenient time.

Not sure if we officially ALOGed this, but splitting the single lsc model running at 40uS into two models running at 23uS and 18uS (lsc and lscaux respectively) has fixed the occasional RFM IPC error seen at the end stations SUS and SEI. There have been zero errors at either end station in the past 31 hours. Previous error rate was one every 20 mins.

Written by Yuta

I calculated the signal amplitudes for Xgreen REFL WFS.
The WFS signal amplitude ratio for SOFT mode and HARD mode is 1:3.8. The Gouy phase separation is 57deg.
Attached figure shows Gouy phase dependence of the WFS signal from both modes. Dots are from Optickle simulation and lines are from analytical calculation.
In my analytical calculation, it assumes high finesse cavity. So, amplitudes are scaled to fit Optickle results in this plot. The ratio of SOFT/HARD or relative Gouy phase does not change. (see Appendix A of T1300497 for more details)

Parameters I used are listed below.

[Parameters]
wavelength: 532 nm
sideband freq: 24.389319 MHz (alog #9708)
modulation depth: 0.1i
input power: 30 mW
power on QPD: 3 mW
cavity length: 3994.4704 m (alog #9626)
ETM RoC: 2241.54 m (alog #9381)
ITM RoC: 1939.52 m
ETM green trans: 38%
ITM green trans: 1%

The SEI wd plotting software was working at the begining of the week and stopped working 2 days ago, prior to the HAM-ISI update. The script reports issues getting data from the NDS server:

Called with arguments: subsystem='HAM', debug=False, lookback=20, chamber='HAM3', lookforward=15, device='CPS', rough_trip_time=

2014-02-13 09:59:29,110 : WDTripPlotter :

Discovering true watchdog trip time...

2014-02-13 09:59:29,110 : BufferDict :

No NDS host and/or port specified.

2014-02-13 09:59:29,110 : BufferDict :

Found host and ports in NDSSERVER environment variable:

    h1nds0:8088

    h1nds1:8088

2014-02-13 09:59:29,111 : BufferDict :

Attempting to establish a connection with NDS server at h1nds0:8088

2014-02-13 09:59:29,115 : BufferDict :

Established connection.

2014-02-13 09:59:29,115 : BufferDict :

Buffers requested at start time 1076291510 and end time 1076291512 for the following channels:

    H1:ISI-HAM3_WD_MON_STATE_IN1_DQ

2014-02-13 09:59:29,116 : BufferDict :

Trying to recover from error by clearing nds2 cache...

2014-02-13 09:59:33,318 : BufferDict :

Buffers requested at start time 1076291510 and end time 1076291512 for the following channels:

    H1:ISI-HAM3_WD_MON_STATE_IN1_DQ

2014-02-13 09:59:50,313 : BufferDict :

NDS server cannot retrieve data for at least one of the following channels:

    H1:ISI-HAM3_WD_MON_STATE_IN1_DQ

2014-02-13 09:59:50,313 : WDTripPlotter :

Unable to create BufferDict(['H1:ISI-HAM3_WD_MON_STATE_IN1_DQ'], 1076291510.0, 1076291512.0, wd_state_mask=[True], abs_threshold_mask=None, host=None, port=None).

2014-02-13 09:59:50,414 : WDTripPlotter :

Quitting program

Hugh, Mitch, and Justin
   Adding payload to HAM4. 
   Using roll up door in LVEA 

 11:10 Done.

Chiller level alarm was heard in shipping and receiving.  Added 3/4 cup of water to chiller, alarm cleared.  Good for another 2 weeks.

Having previously calibrated the IMC mirror alignment offsets (see aLOG 9870), on the evening of Thursday 6th Feb I proceeded to misalign the IMC in all 4 D.O.F.s in turn and measure the RIN spectra in transmission using MC2 trans QPD. This is the same measurement that was performed for the PSL commissioning mode beam jitter measurement as reported in aLOG 8190, the only differences being the more precise calibration of the applied offsets this time, and of course the PSL being in science mode this time.

The first attached plot shows the newly measured jitter spectra on top of the spectra measured in October with the PSL in commissioning mode. Here it is clear to see an improvement of greater than 1 order of magnitude between about 1Hz and 30Hz or so. This roughly agrees with what we'd expect given the measurements on the PSL table reported for L1 in LIGO-T1300368.

The second attached plot shows the unscaled RIN spectra for the IMC aligned, and misaligned in the 4 orthogonal D.O.F.s. Since the aligned spectrum looks very similar to the IMC misaligned spectra, it's reasonable to assume that even in the aligned case the RIN out of the IMC is dominated by the effects of beam jitter. In the ~f^(-0.5) part of the spectrum above about 5Hz the MC mirror motion is not expected to contribute to the jitter, so we can assume everything here is due to coupling from input beam jitter through RMS or DC misalignment of the IMC into RIN in transmission of the IMC.

From the difference in magnitude of the aligned and misaligned spectra we can make some estimates of the RMS alignment offset in each D.O.F. Since the jitter to RIN coupling is linear with alignment offset, the RMS offset in each D.O.F. can be estimated as follows: RMS offset = aligned RIN / (misaligned RIN - aligned RIN) * misaligned offset. For the D.O.F.s studied this comes out as:

I'll continue with some more analysis of the data, and write it up in LIGO-T1300378.

Daniel, Sheila, Alexa

The TMS Baffle PD 1 220.6 PIT -227.1 YAW 2.24 Volts at 0dB gain.  I saved this as the misalignment state. 

Baffle PD 4 (channel 3) 289.9 PIT -289.0 YAW 2.47 V 0dB gain.

Aligned position:255.25 PIT -258.05 YAW saved as aligned state.  This is a change of -0.6 PIT -0.45 YAW from yesterday and alog 10001

Then I moved PR3 using the single shot beam on the camera, it seems centered now.  (PIT -244, YAW -253.98 according to PV info) However, there is something funny about the sliders on PR3: the text entry button says -253, while the number above the slider says -253.

Apparently Epics doesn't know how to round. 

To get cavty flashes I moved the ETM to 243.0 PIT, 74 YAW, these are now saved as alinged.

Tha cavity locked and the IAL servos are running now.

Performances of the ETMX and ITMX ISI were consistent between yesterday evening and this evening, cf the first two attached plots. Although, the ground motion was not that different (cf comparison of the seismometers in PEM_CS and PEM_EX).

First two attachements are showing a comparison of oplev Pitch and ST2 GS13 for ITM and ETM
yesterday night in green (gps 1076202015 2014-02-12 01:00:00 UTC)
this evening in red  (gps 1076301556 2014-02-13 04:39:01 UTC)

Last two attachements are a comparison of the seismometers in Corner station and End X
yesterday night in red (gps 1076202015 2014-02-12 01:00:00 UTC)
this evening in blue (gps 1076301556 2014-02-13 04:39:01 UTC)

J. Kissel, A. Staley, S. Dwyer

In order to trouble shoot her ALS noise model, Alexa took an equivalent measure of the MCL / MCF crossover model using the fast path, where as I chose the slow path. She discovered that the crossover transfer function was a factor of two higher than mine (see 10064). This was notably before I changed the MC2 compensation filters (see 10043). After I changed the filters, I've taken the slow-path version of the IMC_L / IMC_F crossover transfer function again, and can confirm Alexa's result. 

This confirms that the crossover is border-line stable up at 25 [Hz], uncomfortably close to the 29 [Hz] Roll notch. This may explain why ALS CARM handoff has been so difficult last night and today.

Suspecting utter debauchery between the two measurements only two days apart, Sheila and I confirmed the following:
- All digital settings are identical to what I'd described in LHO aLOG 10042
- The 9 MHz modulation depth is set at the nominal +10dBm
- The overall open loop gain has not changed

We tried to check if the demodulation phase had rotated, but the test was inconclusive because we couldn't get any I signal from the demodulator for unknown reasons. We also measured the raw, peak-to-peak voltage of the RF output of the photodiode, and got ~250 mV.

Clearly a more thorough investigation is in order. :-(.
In the mean time the mode cleaner remains locked...

Blue Team

We ramped up the effort to get the geen ALS WFS used for the One Arm Test on ISCT EX, to help us with the alignment-induced noise between red and green.

Here is where we stand at the moment:

- Electronics: mostly installed, see entry by Filiberto and Daniel

- WFSs + cables + patch panel: found, in the EX VEA

- Picomotors, breakout box and cables : found (breakout box already at EX), picomotors mirrors on Evan's desk

- New WFS layout designed by Jax and Evan: lenses, mirrors, beam splitters -- all in hand

- Cabling: Mostly done by Filiberto between the field rack and the remote rack; the cables between the optics table and the field rack need to be made - list sent to Filiberto

Plan for tomorrow/Friday (in parallel with Filiberto's work)

- Get new optics, WFS and picomotors on the table (when the green team is not working)

- Install patch panels and cables as they become available

- Update electronics drawings

- RCG model update

J. Kissel

I've found a window to stick in the proper coil driver compensation filters into MC2. As described in LHO aLOG 9956, the compensation now correctly compensates the modified M2 triple acquisition driver,

FM1    zpk([13],[65],1,"n")
FM2    zpk([11;21],[1;210],1,"n")
FM6    zpk([65],[13],1,"n")
FM7    zpk([1;210],[11;21],1,"n")
The Binary IO filter logic had been changed long ago, so everything works as designed now. Also, I've cleaned up and removed what was in FMs 3 and 8, which was redundant with FM6 and FM7. The new filter file has been committed to the userapps repo.

J. Kissel

We've discovered that the H1 SUS MC2 compensation filters are incorrect for the M2 stage coil driver, having never been changed after the analog coil driver was swapped out for a beefier drive (see LHO aLOG 9956). It turns out, by lucky coincidence, we've been operating the new coil driver in a state (State 1) where it's frequency response is flat, and the compensation filters -- though wrong -- cancel each other to also be flat, so the overall crossover loop gains remained unaffected.

Just to be sure, however, I too a "pre" measurement of each crossover of the IMC_L loop gains. I attach the results, and summarize below.

Crossover     UGF [Hz]    Phase Margin [deg]
MC_L/MC_F     14.5                39
M2/M3         7                   38
M1/M2         0.125               36 
These numbers are comparable to LLO's numbers (see, e.g. LLO aLOG 4331).

Templates can be found here:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/MC2/Common/Data/
2014-02-11_H1IMC_M1-M2_Crossover_OLGTF.xml
2014-02-11_H1IMC_M2-M3_Crossover_OLGTF.xml
2014-02-11_H1IMC_MCL-MCF_Crossover_OLGTF.xml

I caused a HEPI trip this evening, messing with arm cavity slow feedback to HEPI. 

While trying to restet this, I once again became annoyed by how the isolate script sets the current setpoint to something other than the target setpoint for Ry and RZ.  Forgetting this is part of why it took us several hours to recover from the hepi pump trip this afternoon, and it seems like by continuing to have the script do this we are shoting ourselves in the foot.  I have heard that the script does this because of fear that HEPI can't handle these large offsets, but we have been using these large target positions for more than a month, so it seems HEPI can handle them.  If that's true, is it possible to fix this script?

Having a closer look at the offsets, I noticed that the location was not coming back to the set point even after waiting a long time.  I attached a plot of the target location over the last 60 days, it has really never been at the set point.

AS far as I understood, this after noon after our long struggle to get ETMX back after the hepi pump trip, Jim got it back one DOF at a time using 250mHz blends on stage 1, Tcrappy on stage 2, and using the 60 Hz notch in the stage 2 controllers (which is for level 3 but while we are still using level 2 controlers we need to engage FM5 by hand). (correct me if I'm wrong Jim)

Instructions for what worked for me now are:

HEPI:

untrip watchdog

Comands 2, Isolate level 1

Important! Check that DC bias current setpoints match the target setpoints.

ISI:

Set T240 watchdog thresholds to something large

Set stage 1 blends to 250, isolate level 3.

Wait a long time, get distracted by other work, come back in a half hour....

change stage 1 blends to Tcrappy

Isolate stage 2 level2 with Tcrappy

All set!

I swapped in a new HTTS filter file with corrected dewhitening filters (what claimed to be 10:0.4 had actually been 40:1.6). I checked that RM1 and RM2 still damp stably.

I've started on a round of undamped TFs on RM1 and RM2 to check that I get the expected results without post-hoc corrections.