Evan, Yuta, Kiwamu,

Commissioning of the dithering system is underway.

A summary of the red commissioning from this morning:

• We locked the PRMI with the 1f signals and noticed that the lock was fragile.
• Then we realized that the demodulation phase of REFLAIR_RF45 was set back to 133 deg which should be 144.6 deg (see alog 9930) to make the two loops decoupled.
  • This was missing in the guardian
• Once we confirmed that the PRMI can stay locked, we moved on to PRX.
• We started commissioning the dither system (ADS = Alignment Dither System).
  • This is still an ongoing task.

(Alexa, Jeff)

The IMC-X_M1 and IMC-X_M2 wresg calibration filters are off by a minus sign. I have attached the plots depicted in foton and those produced by Jeff's model. The phase is 180 deg in foton, but should be 0 at DC. I have not updated foton, but an email has been sent out to the relevant parties.

The BSC-ISI watchdog plotting software was reported disfunctional by Hugh earlier this week.

I looked into the scripts and they were fine. What I had missed is that Charles had updated the BSC-ISI WD screens, wich thus needed to receive an svn up at the site to match the latest wd_plotting software update, performed when updating the HAM-ISI models last week.

I run the the svn up on: /opt/rtcs/userapps/release/isi/common/medm/ISI_CUST_CHAMBER_WATCHDOg.adl remotely.

The WD plotting software now works on all the SEI platforms of H1.

HAM2 and HAM3 as well as the HEPIs tripped at the exact same time (actuator trip for all of them) @ gps 1077061619 (15:46 PT)

15:47 DAQ Restart. Support of h1lsc model change.

   Tested the dust monitors at End-Y. Found dust monitor #2 (in the test stand cleanroom) was not working. I moved dust monitor #1 (from the spool area cleanroom) to under the test stand, and verify its operation. Dust monitor #2 has been returned to Richard. 

Seems like it was yesterday's burt-restoring to a bad time for ALS WFS. Manually restored them.

At 14:25:00 and 14:26:00 a signal was injected into the seismometer channels for H1:PEM-MX to test a suspected delay in signals showing up in dataviewer displays in the control room.  There was no delay. Signal was injected by striking the floor of the VEA with a heavy plastic mallet.  There is a time conversion issue on playback in dataviewer in which the UTC time entered is not the time that gets played back, but if GPS time is used, it is correct.  This will be investigated and corrected.

Except for Corey doing some last moment inventorying, the Cartridge is ready for install.  The Test Stand is stripped of all field cables, in-vac cables are all tucked away, accessible areas of the ISI were wiped down (not too much collected it seemed,) and covers are on ready to drop around Stage0 when the assembly lifts from the Stand.  No incumberances seen at this time.

Thanks to Betsy & Mitchell.

Keita is getting started with green WFS, so we are doing the strait shot alignment first.

Baffle PD 1: PIT 221.0 YAW  -228.1, saved using the new guardian state

Baffle PD4 PIT 290.6 YAW -289.8 saved as well

Alinged: 255.8PIT  -259 YAW saved as Alinged

I didn't move PR3 since the spot already looks centered on the camera: -244 PIT -254 YAW

Installed DustMonitor 12 in clean room over Ham5.  Alarm levels are set high at the moment as the chambers are closed.

Cleaned the lens and repositioned the camera.  Zoomed in and focused on the ITM.  We can see PRMI spot on optic.  Someone may want to make more adjustments.  The camera view is probably upside down.

This completes dewar vacuum jacket pumping exercise.  Summary below: 

8514374 As found = 780 microns -> As left on 12/20/2013 TC = 4 microns, Pirani = 1.5 x 10-3 torr, 
8514372 As found = 28 microns -> As left on 1/23/2014 TC = 4 microns, Pirani = 1.4 x 10-3 torr, 
8514371 As found = 61 microns -> As left on 1/27/2014 TC = 7 microns, Pirani = 1.6 x 10-3 torr, 
8514375 As found = 45 microns -> As left on 1/31/2014 TC = 6 microns, Pirani = ? torr, 
8514376 As found = 49 microns -> As left on 2/4/2014 TC = 6 microns, Pirani = 1.7 x 10-3 torr, 
8514377 As found = 42 microns -> As left on 2/7/2014 TC = 6 microns, Pirani = 1.8 x 10-3 torr, 
8514379 As found = 81 microns -> As left on 2/13/2014 TC = 6 microns, Pirani = 2.0 x 10-3 torr, 
8514380 As found = 58 microns -> As left on 2/21/2014 TC = 7 microns, Pirani = 1.8 x 10-3 torr.

----------Morning Activities---------

• EY work (SEI Cabling, ACB staging, etc) completed at 11am (Hugh, Mitch, Betsy)
• LVEA transitioned to Laser SAFE
• Assembly of mirror mounts for Pcal (Craig & Chris)
• Luis is at EY for Electronics documentation
• Sheila taking down EX Beckhoff system at 10:15am
• Building up ITMs  starting at 10:40 (Betsy & Travis)
• EY Dust Monitor #2 was removed and #1 was put in the Test Stand cleanroom (Jeff & Patrick)
• Went through PSL Checks (no real change from check I ran on Wed)
• Richard installed new Dust Monitor #12 at HAM5/6 (12:15)
• Richard working on ITMx camera
• Praxair at CP2 around noon
• Filiberto moving cables from Test Stand to BSC10
• Handing off end of shift to Thomas

Dave B., Patrick T.

Just realized that the system time for h1conlog is ~ 1 min 42 sec in the future. NTP needs to be set up. We will do this during Tuesday maintenance.

We also added three channels for testing:

H1:PEM-CS_GDS_0_RSET
H1:PEM-CS_GDS_0_SW1
H1:PEM-CS_GDS_0_SW2

(Jax, Keita)

Yesterday morning we measured the sensing matrix for the ALS WFS. We did this by Injecting 30000cts at 5Hz into H1:SUS-L2_(I/E)TMX_L2_TEST_(P/Y)_EXC, then measuring the transfer function between H1:ALS-X_WFS_(A/B)_I_(PIT/YAW)_OUT and H1:SUS-(I/E)TMX_L3_OPLEV_(PIT/YAW)_OUT. 

In cavity basis:

Pitch Sensing Matrix: (WFS ct/uRad)

Pitch Input Matrix: (uRad/WFS ct)

Pitch Output Matrix:

Yaw Sensing Matrix: (WFS ct/uRad)

Yaw Input Matrix: (uRad/WFS ct)

Yaw Output Matrix:

Raw data: 

Useful information for determining sign conventions from raw data:

1. ETM/ITM Yaw is defined with positive as a counter-clockwise rotation of the optic around the z-axis. 

2. ETM/ITM pitch is defined as positive pitch "down", but ITM oplev is set such that an increase in pitch gives a decrease in oplev measurement.

ETM Yaw:

ETM Pitch:

ITM Yaw:

ITM Pitch:

[Evan, Paul]

Here is a summary of the analysis of beam size measurements reported in 9898 and previous, in context with expected parameters from a model of the PRMI.

The first attached plot shows the ITMX direct reflection : PRM direct reflection beam size ratios predicted at the ISCT1 measurement location, as a function of ITMX susbtrate lens and PR2-PR3 distance offset*. The diagonal lines on the plots indicate the measured value of this beam size ratio**. There are also 3 pairs of red and blue vertical lines on the plots. The blue lines represent "cold states" and the red lines represent the designed for "warm state" with a +50km (+20uD) thermal lens in the ITM. The left-most pair of blue and red lines corresponds to the "expected" ITM lens state: -80km (-12.5uD) non-thermal lens in the ITMX substrate. The middle pair of blue and red lines corresponds to the "design" ITM lens state: no non-thermal lens in the ITMX susbtrate. The right-hand pair of blue and red lines corresponds to the "estimated" ITMX lens state, given the assumption that the generalized PRC parameter 2*PR2->PR3 - PR3Rc is as designed.

By assuming PR2-PR3 is as designed, we can estimate an ITMX non-thermal lens of +15uD (6.7km). The estimate from x-axis data and y-axis data agrees very well here. By assuming that the ITMX non-thermal lens is the -12.5uD (-80km) that came from surface figure measurements, we can estimate that the PR2-PR3 offset is +8.82mm. However, it should be noted that other simulation results showed that PRY is very likely to be unstable for such a large PR2-PR3 offset. As far as I'm aware, this was not observed during PRMI commissioning, though I'd appreciate some confirmation if anyone has any. Of course, any combination of PR2-PR3 offset and ITMX lens deviation that gives beam size ratios along the diagonal line is not discounted by these measurements.

The second attaced plots shows the same data for the ITMY measurements, which were taken while 4W was being applied to the ITMY ring heater. For ITMY we have no prior information about the non-thermal substrate lens, so the blue and red lines are not added. The only sensible prior information to assume, just for comparison, is that the non-thermal substrate lens is 0uD (+inf km). This is the right hand edge of the plot. The black dashed line represents the expected substrate lens caused by 4W of heating with the ring heater, using Aidan's number of -13.6uD/W. The diagonal lines again represent the measured beam size ratios. This seems to suggest that the non-thermal substrate lens is around +32uD (31.25km) in the x-axis and +40uD (25km) in the y-axis, again under the assumption that PR2-PR3 distance is as designed. From the ITMX plot and the ITMY plot, we should at least be able to pin down the difference in non-thermal lens power between ITMX and ITMY, even if we can't pin them down individually.

Next, I wanted to take a look at the consequences for actual mode matching in the interferometer, specifically between the IMC and PRX, PRX and XARM.
The third and fourth attached plots shows the IMC-PRX eigenmode overlap and PRX-XARM overlaps respectively over a slightly larger xaxis-range than for the first attached plot, but with the same blue and red lines for ITMX susbtrate lenses. Both diagonal lines from the plots in the first attached figure are included on these mode overlap plots: it is clear that lines from x and y-axes lie very close to each other. The important thing here is that at the "estimated" ITMX non-thermal lens value +15uD and the as-designed PR2-PR3 length, the IMC-PRX overlap is 99.5%(x) and 98.5%(y), and the PRX-XARM overlap is 99.7%(x) and 99.2%(y). If we allow for a +20uD (+50km) thermal lens on top of this value, these overlaps change to IMC-PRX 99.4%(x) 99.8%(y) and PRX-XARM 99.8%(x) 100%(y). In short: IMC-PRX and PRX-XARM should be mode matched well at cold and warm states if we believe the beam size measurements. Of course, the mode matching starts to suffer at a bit lower power than planned as a result of this, but PRX-XARM should still remain >97% for effectively all powers up to 125W. Also worth noting here is that for the mode matching, it doesn't matter right now whether it's the PR2-PR3 length that is off or the ITM non-thermal lens power, since the slope of the mode overlaps with respect to PR2-PR3 offset matches the diagonal lines from the beam size measurements.

I've also been looking at PRX-PRY overlaps for comparison with PRC gain observations as a function of ring heater power, but this post is already too long so I'll post that later.

* PR2-PR3 was varied in the simulation, but for these purposes it's degenerate with PR3 Rc change. The actual quantity that seems to matter most is (2 x PR2-PR3 distance - PR3 Rc), but in the simulation it suffices to vary just one of these. In practice we can only change PR2-PR3 distance so I plot that one.

**One caveat there: since the x-axis PRM measurement is believed to have been affected by the reflection from the back surface of the pick off window, I used the the model value of PRM direct reflected beam size and the measured value of the ITMX direct reflected beam size for computing the ratio. For comparison, the y-axis PRM direct reflected beam size (unaffected by the second reflection form the window) was measured to be 2.15mm, compared to the model value of 2.138mm. This is less than 1% difference, and the PRM model x-axis beam size was scaled by 2.15/2.138 to account for the possible small error in measurement location.

Sheila, Alexa

After spending the afternoon on the arm locking, we spent some time looking at the COMM handoff.  (Plots coming in the morning...)

• By lowering the PLL gain (to lower the gain peaking frequency) we can get the COMM ugf to 35kHz.  (using PLL gain 19, CM in1 gain 27). 
• The 27kHz line from the end station is large in the COMM error signal as well. (so we wouldn't wat to use a high bandwidth in this loop anyway).
• We then went back to the nominal gains and had a look at the coherence with the OPlevs of our refl control signal, and the COMM control signal.  The ETM motion was higher when we did this, and it had coherence around the pitch resonaonce, the ITM didn't have much coherence.
• We measured some tranfser functions from pitch of the ETM to our control signals, and should be able to use this to make a projection of the frequency noise due to pitch of the ETM. 
• We noticed that the cavity transmitted power fluctuations were much smaller with the dither alignment servos off.  Suspecting clipping, we checked the single show bem position on the camera on ISCT1but it seemed fine. However when we engaged the dither servos the cavity transmitted spot was not centered on the camera.  After a manual realingment the cavity transmitted power seems much more stable. 

I am leaving the arm cavity locking, PRM parked and ITMY misalinged, and the alingment servos off. 

The BS IS tripped on GS-13 watchdog at 1328 utc this morning.  Traffic, wind, something--plotting scripts still not functioning...

Anyway, I brought it back to lvl2 with 750mHz blends on stage2 and T250s on all Stage1 blends except T100mHz_0.44 blends on X & Y dofs.

I reset the target positions, there was about 700nrads on RX and <4um on Z, all other shifts were less.   Please let us know if this impacts any alignments.  This allowed for a one button isolation.