On Friday, Gerardo and I encountered an issue while processing the optic as per the ear bonding procedure.  During the processing, the optic suffered a 3mmx 3mm crack at the bevel on the HR side of the optic and some scratches out near the edge of the HR face.  We're working to understand whether or not it can be used in BSC3, but our expectation is that it can, owing to the small nature of the crack.  We are also working with COC/SUS/SYS so this damage does not occur during future processing.

Kiwamu, Stefan

We did some tweaking of the PRCL servo in order to get stable locking of the low finesse half-PRC for further actuator commissioning.

- We are feeding back to PR2 and PRM.
- We removed any low-pass filter from the PRCL control filter, but left a CPL300 in the M3 locking filters of PRM and PR2. Currently only M3 and M2 are feeding back - the filter modules snapshots are below.
- This gives a PRCL UGF of about 18Hz (see OLG measurement, as well as the signal levels in counts below). 
- With that, fine-tweaking the alignment showed that PR3 was moving too much in pitch. We increased its L and P damping gain, and engaged corresponding boost filters. (snapshot below)

[Dick, Daniel, Koji]

The POP 2f demodulator unit previously installed on row 28 of the ISC R2 rack (c.f. this entry ) was replaced with the 2f demod unit.
This unit has a 24MHz LPF and a 80MHz HPF on CH1 and CH2, respectively, forming a diplexer configulation for 18MHz (2xf1) and 90MHz (2xf2) signals.
Therefore, the temporary power splitter for the POP 2f path was removed.

Because of this action, we expect that the demod phase for the POPAIR18 and POPAIR90 were changed.

The 3f demods (CH3/4) still have the power splitter. This will be removed when the 3f diplexer unit is installed on row 27.

We also cleaned up some of the RF cables:

- The REFLAIR9 cable plugged on row 34 is now routed through the patch panel on row 27.
This means that the demod phase of the REFLAIR_A_RF9 was changed.

- The cable for REFL9 was made and connected to the demodulator on row 34.

- Unnecessary connectors/cables were removed from the patch panel on row 29.

   After making several adjustments to the Coil Holder, the BOSEMs, flag alignments, and adding the third Coil Holder Mounting Bracket on H1-SR2, a new set of transfer functions were taken Friday evening. (See aLOG #9211). The plots for this latest set of transfer functions are posted below. All scripts and data files have been committed to the SVN repository. 

Note: The 4th Coil Holder Mounting Bracket has been modified and is being run through C&B this week. It will be installed on the suspension as soon as it comes out of clean and Bake.    

Apollo doing some cutting 920-940

Here is an site email announcment made with regards to ER5:

This is a step in getting closer to our ultimate goals as Operators, and that is running shifts during a Science Run. 

Thanks!

Corey

Three days of minute trend maxima for the LVEA PEM seismometer and the LVEA weather station, ~9:00 AM local on Friday through the current time.  The period of highest winds was Saturday afternoon and evening.

I set the mode cleaner requested state to down and turned off the alingment offsets on MC1 to avoid confusion from MC flashing.

[Stefan, Kiwamu]

Here are our corner locking activity today.

We completed the alignment of all the diodes on ISCT1:

• REFLAIR_A
• REFLAIR_B
• REFL camera
• POPAIR_A
• POPAIR_B
• POP camera

The razor blade beam dumps for the POP PDs are not aligned yet because the beam was not bright enough.

The demod phase of 2f signals were adjusted:

We adjusted the demod phases to get the signals maximized in I. When the 2f signals go positive, it indicates that the carrier is resonant in the power recycling cavity, and negative for the sidebands on resonance.

• H1:LSC-POPAIR_B_RF18_PHASE_R = -8
• H1:LSC-POPAIR_B_RF90_PHASE_R = -90

Note that the demod board that currently in the rack is not the final version (see alog 9103 and 9093).

The signals looked too small for the simple Michelson:

We misaligned PRM to see how big signal we could get for the simple Michelson. However, the RF and DC signals looked too small to acquire the lock. For example, REFLAIR_A_LF fluctuated only by a few ADC counts. It seems that it would be very tough to lock the Michelson without the power recycling at this power level.

PRM and PR2 are saturating:

We then moved onto PRX in order to establish stable lock of PRC. Wth both PRM and PR2 actuated, we could still see a saturation in them. We must revisit the multiple-stage offload in PRM and PR2 and activate the top stage stably. Currently none of the M1 stages are not in use because we haven't commissioned them. Also, at the same time, we should spend some time to reduce the seismic disturbance in the first place to ease the PRC lock.

I found that the diffraction power of ISS had decreased again.

This time, it seems that somebody changed the offset setting for some reason (or maybe it was related to Stefan's ODC activity, see alog 9222). I set it back such that the diffraction power stays at 10%.

H1:PSL-ISS_REFSIGNAL = -1.93 (had been set to be -1.95 by someone on 11th of January)

Note that this value is the same as what I set on this past Friday (see alog 9219)

I did some cleanup work for the PSL odc channels

- Updated the ODCV2.mdl library to use the MODAL_RATE part from RCG 2.8. This replaces the need to manually set the model rate. This library is in almost every model currently running, but there is no real urgency to push the change everywhere.
  Updated SVN: ODCV2.mdl revision 6837

- Added ADC/DAC overflow and Excitation monitoring to ODC for the PSL. Updated and restarted the following files (SVN revision 6839):
        h1pslfss.mdl
        h1psliss.mdl
        h1pslpmc.mdl


- Updated the PSL ODC medm screens. PSL_ODC.adl                    SVN revision 6838  (picture attached)
- Updated the ODC overview screen.  SYS_CUST_ODC_SITE_OVERVIEW.adl SVN revision 6842

- Updated the h1setODCbitstrings and h1setODCbitmask scripts in cds/h1/scripts to include the PSL settings. SVN revision 6841.

I went through the X arm alignment again, unfortunately the computer crashed before I saved the alog but the centered values for TMS are 147.5 PIT -234 YAW (+10 in pit compared to yesterday, +6 in YAW) ITM 72 PIT -62 YAW (basically the same as yesterday).

It was easy enough to find the pointing of TMS and the ITM using the baffle PDs starting from the last alingment in alog 9191.  However, I could not easily find the ETM pointing.  I did find the beams on the baffle PDs by doing a slow scan (Strip chat screen shot attached) and found:

with 40dB gain, PD3 has 2.1 V with ETM PIT 292 YAW 44.  REFL B then has 15400 counts

with 20dB gain PD1 has 2.6 Volts with ETM PIT 246 YAW 101 Refl B has around 1100 counts. 

From this the aligned position should be 269 PIT 72.5 Yaw.  This is remarkably different from where I found similar fringing yesterday, 384 PIT -77 YAW.  While there was some HEPI commisioning yesterday afternoon, I would have expected this to change the TMS and ETM alingments by the same amount, so either one or the other of these alignments is bad or something moved.  Also, the ETM oplev has moved quite a lot. 

The PD levels for these alingments seem suspicously low, if the mode matching was perfect I would expect the intensity on the diodes to only decrease by a factor of the ETM reflectivity compared to the straight shot from the transmon (alog 9191) Instead these are a factor of 100 and a factor of 10 lower. Either these are not the right beams or the mode matching could be wrong.  There was clearly some fringing on the refl PD and COMM (which I am using as an X arm trans readback for now). 

It is possible to find some light on the PDs for ETM alignments that don't make sense (PD1 on the wrong side of PD4 ect), probably a second bounce beam hitting the PD. 

I also changed the polarization into the X arm fiber (photo of settings attached). 

Once I saw some fringing I was able to "lock the arm"  and the "lock"  would stay for 10s of seconds although I'm not sure this was really locking to any reasonable mode of the cavity.  On the camera I could see that the beam motion is large, we have verry high winds.  I also could not go out to the end station to work on the locking because of tumbleweeds, photo attached. 

Keita, Koji, Stefan

I went out to ISCT1 and steered the REFL beam on to REFLAIR_A_9. After a little bit of alignment tweaking and closing the PRC loop (no MICH loop yet) we got some pretty decent REFL dips. More later this weekend.

Looking at the IMC transmitted light, I realized that the laser power occasionally dropped by 15% and came back to the nominal level in 10-ish seconds (see the attached screenshot). Since I knew this was usually associated with ISS, I took a look at ISS. Sure enough, the diffracted light was too low and it was about 5% or perhaps even less. According to the trend (see the second file attached), it seems that the diffraction power started decreasing after around 18th of December in the last year and recently dropped steeply. This too low diffraction was causing the frequent unlock of the ISS loop.

I adjusted the offset voltage to increase the diffraction power to 10% as was done by Doug (see alog 7810).

H1:PSL-ISS_REFSIGNAL = -1.93 ( which had been -2.00)

It seems this fixed the glitching issue as of now.

I updated the the LHO PSL code (FSS, ISS, PMC) to syrnchronzie with the LLO status, using all the common parts already in svn. This was slightly tricky, since there were some local changes at LHO that were never committed because the LLO files had changed. This also brings the PSL ODC code to the same status as LLO. Some more ODC threshold setup work will be required over the weekend to make sure the channel is green when it should be.

Files checked into svn: version 6832:
h1pslfss.mdl
h1psliss.mdl
h1pslpmc.mdl

I also re-implemented the local LHO changes to the common files, namely:
- $Id$ and $HeadURL$ tags for svn version keeping 
- Defining science channels by adding * in the DAQ block for the following channels:
   pslfss: FAST_MON_OUT, MIXER_OUT
   psliss: AOM_DRIVER_MON_OUT, PDA_OUT, PDB_OUT
   pslpmc: HV_MON_OUT, MIXER_OUT

Files checked into svn: version 6833:
pslfss.mdl
psliss.mdl
pslpmc.mdl

I guess LLO should syc those files to have the PSL run of the same library at both sites.


There is one more thing: psldbb.mdl I did not touch it today. LLO is up to date. LHO has some local mods (presumably from the MATLAB2012 move), BUT:
Both versions are so messed up with wiring that I do not dare touch it.

[Alexa, Koji, Kiwamu]

We finally completed the in-vac work in HAM1 and the Apollo crews put the door back on. All the necessary beam comes out to ISCT1 and all the necessary beam hit the in-vac diodes. Yeah!

Some pictures will be uploaded in ResouceSpace later.

Here are a list of what we did today:

• TMSX was aligned to make sure that the green light hits the center ITMX (reported in alog 9203).
• Sheila aligned PR3 to get the green light on the iris on ISCT1 (reported in alog 9191).
• We placed the beam dump in the position where the beam should be.
  • This is the one we could not align yesterday (see alog 9196).
• We checked the spot position of every optic in the ALS path with the green light.
  • They looked good.
  • Therefore we didn't touch the alignment of these mirrors.
• We checked the spot position of every optic in the POP path with the infrared POP beam and with an IR viewer.
  • They looked good.
  • The beam still landed on the center of the bottom periscope on ISCT1.
  • Therefore we did't touch the alignment of these mirrors either.
• We opened the shutter of the PSL/ALS light pipe to check the alignment of this path.
  • It was a bit too high and therefore we steered the top periscope mirror of the PSL to lower it.
  • The horizontal alignment was good from the beginning.
• We moved onto the REFL path.
  • The REFL beam coming out from HAM2 toward HAM1 seemed a bit too low by probably 5 mm.
  • The horizontal alignment looked very good.
  • Even so, the beam on RM1 and RM2 and their downstream looked well centered. So we didn't change anything.
  • The beam was already on all three diodes from the beginning.
• The tip-tilts were found to be not damped.
  • There was no damping signals flowing through the model. I am not sure why we lost the last good settings for them.
  • Koji and Jeff Kissel worked on this and finally made them damped.
• We centered the beam on the REFL LSC diode by steering the steering mirror (which is, technically speaking, a BS) in front of the diode.
  • This was done by looking at the digitized DC signal.
  • Also we moved the black glass beam dump, which is supposed to catch the reflection off of the REFL LSC diode, by an inch or to the west because the beam had been on the edge of the black glass.
• We found that the reflected light off of the WFSs were hitting their steering mirror and not making to the black glass beam dump.
  • Note that WFS_A, which is the PSL side of the WFSs, didn't have a black glass beam dump. Therefore we asked Corey to give us a dump and we newly installed it.
  • We introduced some more rotation in the angle of the WFS detectors to get the reflected light spatially separated from the incident.
  • We took several pictures before and after changing WFSs' orientations.
  • Then we fine-adjusted the location of the black glass beam dumps to catch the reflections.
• We centered the beam on each WFS by steering the picomotorized mirrors on the sled.
  • This was done by looking at the digitized WFS_DC signals.
  • Also we had to switch the WFS interface D-subs with the ones of the analog WFSs to get the signal available.

(Alexa, Kiwamu)

We noticed that the FSS was osillating significantly. I first lowered the resonant threshold from .8V to .5V. I also decreased the Common Gain from 30dB to 10.4dB. This seemed to help. It's possible the oscillation was due to instability in the MC servo. 

After an initial assessment that stated "not too bad, not too good" (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=8919), which was based on just two data points (beam radius on WFSs), I added the third point further downstream of the WFS2 and it turns out that actually it's excellent.

In the attached plot, blue circles represent the measured beam width, blue crosses on both sides of blue circle represent the potential position error (Jamie claims +-1cm though probably it's too generous), red line is a fit over the three points, green is the curve generated by the design parameters.

As you can see, in both horizontal and vertical direction, the waist is very close to the middle of the WFSs, and the waist radius is very close to the designed 250um.  Gouy separation for X (horizontal) and Y (vertical) are 82.6 and 87.1 degrees, respectively.

This was obtained from just two iterations of measurming at WFS1 and WFS2 and pushing RM2 toward RM1 based on the measurement. Downstream was measured just once after we were satisfied with WFS1 and WFS2.

Distance from RM3 to the first lens on the sled is, according to Jamie, between 48.0 and 48.25 inches.

Also, as noted earlier, the above data was obtained after having moved RM2 toward RM1 by 22.5mm. Everything else is the same as what Sheila reported much earlier.

We also measured at one point between RM3 and the sled (14.5" downstream of RM3).  Together with upstream number measured yesterday (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=8893), these are:

In all of the above measurements, "Profile averages" was 10, "Rolling profile Averages" was 3, the actual number of measuremets (i.e. the number of scans performed before I stopped the measurement) were larger than 10 but I don't know if the software was taking more than 10 points into the statistics or not.