Alexa, Kiwamu, Koji, Sheila, Stefan

In the morning we worked on getting the green beam correctly positioned onto the periscope mirror and onto ISCT1. First we adjusted PR3 such that the beam was centered through the Swiss cheese baffle opening and the viewport. We then had to move the periscope mirror by 1.5inch toward the east, and move the top mirror up slightly. Following this, we finessed our adjustment of PR3 so that the ALS-X green beam was 4mm toward the east in the horizontal direction and 6mm up in the vertical (as specified by Ketia's alog). We also ensured the beam hit the periscope on ISCT1 with M11.

In the afternoon we were able to see IR POP flashes in HAM1. We had to adjust M10, M15, M16, BDIV1. The pop beam was centered on the LSC_POP_A PD; however, we do not see a strong enough signal. We do see a signal when we shine a flashlight onto the PD. We also aligned the pop beam onto the viewport towards ISCT1. Koiji adjusted the periscope location on ISCT1 so that the pop beam was well centered.  

J. Kissel, D. Barker

I'll write a more detailed description of what was done later (and what will need to be done at LLO to absorb the changes), but I've *finally* finished the modifications to HTTS screens, and compiled and installed the new monitor model for the voltage readbacks of the HAM-A drivers. I don't claim perfection, but it's certainly good enough to commit to the SVN and release for more broad consumption.

New models:
${userapps}/sus/h1/models/
h1sushtts.mdl
h1susauxasc0
${userapps}/sus/common/models/
HSSS_MASTER.mdl

Tons of new screens:
${userapps}/sus/common/medm/hsss/SUS_CUST_H*.adl

Edited sitemap screen to call new screens:
${userapps}/cds/h1/medm/SITEMAP.adl

New / updated macrofiles:
${userapps}/sus/common/medm/*.txt

After multiple errors were noticed in our change of basis calculations, we have been checking and recalculating all of them carefully. The results are compiled in T1000388. This document shows:
- the ISI and HEPI orientations with respect of the IFO axis
- the instruments locations and orientations
- the math and programs used to calculate the matrices
- the matrices for every set of sensors, and for each of the two possible modules orientation
- where the matrices are saved in the svn and how they are named
- the transfer functions for each type on instrument
- the old naming convention that we changed because it was too confusing

After thorough review, we are now confident with the HAM-ISI, HAM-HEPI and BSC-HEPI set of matrices. The BSC-ISI review is still in progress. 

Today we installed the HAM-ISI, HAM-HEPI and BSC-HEPI programs and mat files in the local directories, and we committed them in the svn. The old matrices have been backed up in "archives" sub-folders.

We have started populating the new (good) matrices in ETMX. In the coming days, the good matrices will have to be populated in other chambers when commissioning activities allow to do so. Safe.snap files will have to be saved accordingly. 

I modifed rtsystab on h1boot and the STATE_WORD overview medm screen to add Jeff's new h1susauxasc0 model. We will add this to the DAQ tomorrow.

Looked at time series and of course suspecting the actual tilting found coherance between the T240 and the HEPI IPS--See first plot.  The Coherence plot is from the tilt period; untilted shows the same coherence--near 1 from 10 to 100mHz.  The power spectra show the increase power in IPS_RY when tilted (ref-brown) relative to the non-tilted IPS and the tilted IPS_RX--we aren't tilting RX.  Like wise the upper right graph shows the elevated noise in X_T240:

The noise in RY IPS becomes noise in the T240 X as the T240 is so very sensitive to tilt.  So HEPI is doing this to the T240 when HEPI tilts.  Why?  Just the large drive from zero?  Remember, this HEPI is not yet commissioned and this tilt is just open loop...

Looked at the HEPI Pump next.  See the second plot below.  This shows a few days where there was some long stretches of either HEPI Tilted or not.  In the two left graphs are the same IPS signal and I've zoomed into the non-tilted and tilted times and seen by the magnitude of the numbers.  The zoom scale is the same and the elevated noise here is apparent.  The two right graphs are the HEPI Pump Station Output Pressure and the controller output to the pump motor.  There are some transistion glitches during the large changes to tilt the HEPI and the control output changes to deal with the different valve position at the Actuators (Maybe?) but otherwise, the pressure and control are not noisier during the tilted HEPI.

Looked at zoomed in time of IPS tilt and the pump control.  See third plot.  I've offset and scaled the curves to get them to show on the same plot.  I'll look at more case of T240 glitches(excursions) but I think this plot suggests a correlation of large fluctuations of the Pump pressure (I know I plotted the control but it is similar) to the excursions of the IPS and ultimately tripping the ISI from T240 triggers.

Attached is a linear response graph of the ETMX OL to convert the QPD signals to uradians.

The calibration numbers are placed into the gain fields:
H1:SUS-ETMX_L3_OPLEV_PIT_GAIN == 76.72
H1:SUS-ETMX_L3_OPLEV_YAW_GAIN == 65.33

These are the open light, offset and gain values for the H1SR2 M2 and M3 AOSEMs. MEDM has been updated with these values. 

Level  Open Light  Gain  Offset
M2UL     25178     1.192   -12589
M2LL     27027     1.110   -13514
M2UR     24949     1.202   -12474
M2LR     25904     1.158   -12952
M3UL     25625     1.171   -12813
M3LL     25512     1.176   -12756
M3UR     24952     1.202   -12476
M3LR     24566     1.221   -12283
 

** The LVEA was in laser hazard all day and remains so now
** Both doors came off HAM4 and went over the X arm manifold to their storage locations.
** Commissioners continued in HAM1
** Mitchell continued his baffling work near the LVEA test stands
** Filiberto etc spent time at EX working on PEM cables
** Sheila went to EX in the afternoon to work on the green laser noise eater status readout
** Dust monitor 9 alarmed a number of times but the particle counts didn't exceed the threshold by much.  The monitor flipped between green and white often in the morning.
** When Kyle was working with GV7 in the afternoon for the craning of the HAM doors, four alarms were generated from HVE:LX_X4144BTORR (PT 144) on the mid station side of GV8.  The readout was bouncing near 2.4e-08 all afternoon and the alarms occurred when the value intermittently rose a small amount above the threshold of 2.5e-08 (for instance 2.69e-08). In each case the alarm condition immediately fell below the threshold.
** Lots of CDS, SEI and SUS work (Jeff B, Andres) in the control room

Andres R. & Jeff B. 

   After working through several scripts, missing folder, and missing path related issues, we successfully ran transfer functions and power spectra on H1-SR2. The results appear to be in line with other HSTS suspensions. The data plot files are posted below. All updated scripts and created data files have been committed to the SVN vault.  

I doubled checked that the noise eater monitor is not usefull-  the readback we have is an accurate reading of the voltage out of pin 12 on the laser diagnositcs cable, which the manual says is a noise eater readback.  However, this voltage is around 3.1V when the noise eater is on and when it is off. If we are going to use the noise eater we should have a way of remotely switching it on and off, and it would be nice to have a way to tell if it is oscillating. 

Also, just as a check I tried changing the input polarization of the beam leaving the ISC end table.  The arm cavity was misalinged, and I watched refl_B_LF as I inserted a half wave plate and rotated it. I could reduce the power in the reflected beam by diong this, the maximum power I could get back with the waveplate was the same as we get back when we don't have a waveplate.  So it seems as though the low TMS efficiency is not due to polarization.  This makes sense because we already knew that the input polarization is right (s-pol at the bottom of the periscope).

So the question of why the TMS efficiency is low remains.

Started in 'screen' on h0epics2.

This morning, Gerardo and I prepped the ITM03 test mass (side S3) and it's associated ear (s/n 95) for ear bonding.  He then silicate bonded the ear to S3.  After the usual 2 hours of intermittant inspection, he remeasured and confirmed that the position was within spec.  Tomorrow morning we plan to do the S4 side ear bonding.

Rolf, Jeff, Ben, Dave

Rolf added the susHWWD part to the h1susitmy model, which permits the front end to remotely reset the hardware watchdog and set the operational parameters (trip levels and time-to-trip). Communication is acheived via a single binary output channel from SUS ITMY.

We tested the binary I/O communication lines in both directions. The readback was tested by removing one or both of the 37pin connectors on the HWWD (from the Satellite Amp monitor port) which simulates a loss of LED current. The readback was not initially received by the model, but started working after the cable was reseated. We tested the control function by remotely resetting the watchdog and changing the time-to-trip from the defaut of 20mins to 2mins.

New MEDM screens have been built. An alarm handler was also built.

The running h1susitmy model has been built against the trunk (as of 9th January) to permit the new HWWD part to be used. I have subsequently reset the rtscore/release pointer back to RCG2.8.2

After lunch Jeff will put the ITMY SUS and SEI through a series of tests to verify the watchdog functions correctly.

Alexa, Kiwamu, Koji, Stefan

Today we started with centering the TMS pointing on the ITM using the baffle diodes (with ITMX misaligned) :

Baffle PD1: H1:AOS-ITMX_BAFFLEPD_1_POWER maximized:
H1:SUS-TMSX_M1_OPTICALIGN_P_OFFSET 105,5
H1:SUS-TMSX_M1_OPTICALIGN_Y_OFFSET -208.5

Baffle PD4: H1:AOS-ITMX_BAFFLEPD_3_POWER maximized:
H1:SUS-TMSX_M1_OPTICALIGN_P_OFFSET 174.0
H1:SUS-TMSX_M1_OPTICALIGN_Y_OFFSET -270.0

Center position:
1:SUS-TMSX_M1_OPTICALIGN_P_OFFSET 139.75
H1:SUS-TMSX_M1_OPTICALIGN_Y_OFFSET -239.25


Next we established the visibility into HAM1, i.e. the range of PR3 alignments that result in the x-arm green beam reaching HAM1. The orthogonal slider was left at the initial position.

The numbers below are PR3 alignment numbers (i.e. H1:SUS-PR3_M1_OPTICALIGN_P_OFFSET and H1:SUS-PR3_M1_OPTICALIGN_Y_OFFSET):

initial position:  pit -263.8, yaw -272

disappear up    pit -189
disappear down  pit -330 (spot visible in ham 2, glow starting at -320)
disappear north yaw -188
disappear south yaw -320

on swiss cheese baffle down  pit -353
on swiss cheese baffle up    pit -176
on swiss cheese baffle south yaw -366 (glow on cam from tower yaw -320)
on swiss cheese baffle north yaw -178


center visible: pit -254.5 yaw -254 (using -320 instead of -330 for pit down limit)

center swiss cheese baffle: pit -264.5 yaw -272

JimW FabriceM HughR

Jim identified a problem that I've been harping on for months (Input matrix errors.)  While for me it was improper calibration into the cartesian basis, it was also affecting the ISI & HEPI commissioning.  Once we rebuilt the matrices corrrectly, the ISI commissioning we did before the holiday allowed us to bring the ITMx ISI on line with 100mHz blends (on the translational dofs) and 750s elsewhere.  This greatly lowered the ITMx motion hopefully making IFO commissioning easier; especially with the notch Fabrice added to the X&Y dofs to help reduce Optic Pitching.  ITMX HEPI still remains uncommissioned but that should fall away soon.

The ETMx was brought on too the help the ALS crew with similar blends and this too helped quiet the cavity.  However, just as in the past, the watchdogs tripped on the T240 after a couple hours.  Still looking at that one.

Kiwamu, Sheila

Today we saw that the power on the als refl PD drops when we misalign the ITM. (ITM misalinged, 13000 counts, ITM alinged, fringing up to 18000 counts).  This would suggest that the ETM has a low reflectivity for green.  

We went out to the end station and measured 34mW going into the chamber, and by misaligning the ETM measured 13mW returning.  According the Keita the TMC efficiency is 90% each way, if this is correct for the polarization we are injecting the ETM reflectivity is 47%.  (or if we assume the etm transmitts 24% of the green, it could mean that the TMS efficiency one way is 70%)  We also measured 10mW rejected by the Faraday and 1.4mW in the hartman path. 

The fringes that we saw in the reflected PD DC output and the signal out of the demod seem consistent with a verry low cavity finesse. 

It may be worth checking the polarization of the light leaving the table.  Keita noted that there was more green light in the IR QPD path this time than in end Y: alog 8705  However, the polarization should only change the efficiency of the TMS, it would not explain the signal on the refl PD. 

According to the coating report that Betsy sent  the ETM transmission at 532 is 24% https://dcc.ligo.org/DocDB/0059/C1103233/002/Coating%20Characterization%20Report_ETM08.pdf

Alexa and stefan measured the polarization at the bottom of the periscope to be spol: 8558

The fiber pulling machine upper clamp was binding up when we advance the trolly to the end of its stroke after the fiber is pulled. This advanced travel gives you the clearance to allow you to get the fiber assembly out after the fiber is pulled. This issue has been happening more and more recently and causes damage and gross mis-alignments of the translation stages and goniometer mounts. The mounting hardware fit to the fiber clamps was tightly constrained adding to the problem. There is a bit too much wiggle to the mounting stages that were allowing further issues.
Bottom line, I loosened up some of the fit tolerances and coaligned the top and bottom mounts followed up by a beam realignment. I will revisit this in the AM and pull a test fiber. Hopefully we will not have any further issues. I hope to install more robust stages in the near future.

Laser current set to 1.5 amps.

IR output 1.125W (after the laser head), 50.0mW (after Faraday, we're using wave plate to intentionally dump some power), 10mW after PBS (another  attenuation, we can decrease this, or increase this up to 50mW)

With 10mW going to the PLL diode, we have about -3dBm beat note.

green output 22.9mW (right after the laser head), 17.5mW (after the first Faraday), 13.85 (after the second Faraday), 12mW (just before the bottom periscope mirror)

Retroreflection (measured after 10:90 splitter) 0.73mW, this means that the retroreflection is 7.3mW.

Apparent table efficiency is 7.3/12 = 61%.

Aluminum mirror reflectivity is probably not that good (95%-ish if they're good) (turns out that they're silver, not aluminum, coated, thanks Matt for pointing it out, and this means that the reflectivity of these is 98% or so rather than 95), and there are four such mirrors (TMS telescope mirrors), double path, meaning there are 8 reflections. This should amount to 0.98^8 = 85%-ish.

There is a splitter for QPD (5%? I don't remember), again double path, so if it's 5% splitter this removes 10%. 

0.85*0.9 = 77%-ish.