(Alexa, Sheila)

For the noise budget, we had tried measuring the PDH shot noise by misaligning ITMX and reading out the amplitude spectrum from IMON of the demod. This amplitude spectrum was clearly not pure shot noise at low frequency; there seemed to be some scattering and fringe wrapping (see green line in plot). We went to investigate this by putting a HR 532nm mirror at the bottom of the periscope and repeating the measurement; the noise at low frequency subsequently decreased significantly (see red line in plot -- unfortunately I should have taken more frequency spans). There is stil some acoustic noise at around 100Hz but it's less than in the first measurement (and in the overall PDH noise, the fiber noise is dominant in this region anyway). We removed the HR mirror and tried misaligned ITMX to various different positions and saw that the amplitude spectrum changed around. Clearly, in this measurement we are picking up scattering in the cavity which comes about from misaligning ITMX. We have now convinced oursevles that we do not have any major scattering on the ISCTEX table. 

I have attached the data with the HR mirror in place.

The awgstream software for the control room has been updated to increase the size of the channel list it reads.  This should solve the problem encountered Wednesday in which H1:SUS channels could not be excited using awgstream.

Yesterday night and this morning some diagonalization measurements were taken with pum drive on etmx and itmx. The low coherence for the pitch drive described on the previous alog was due to the optic not centered enough on the oplev, so both ETMX p2p and y2y were remeasured. Those measurements can actually be really fast (15/20min each).
ITMX measurement has some calibration factor of 1.56 for Yaw and 1.83 in Pitch. T1100378 was the reference for calibrating the drive from cts to N.

Attached are the plots comparing the measurement and the model (wirerehang for itmx, fiber for etmx). Note that there is a sign error in ETMX Yaw, so we should double check if that comes from the Oplev sign convention.
 

• The data was processed (removed points with bad coherence) and calibrated in rad/N.m. It lives in :

ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Results/quad_{p2p/y2y}.mat

ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL2/Results/quad_{p2p/y2y.mat

• Dtt templates were saved under : 

ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Data/2014-03-06_H1SUSITMX_{P2PY/Y2PY}_WhiteNoise.xml

ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Data/2014-03-04_H1SUSETMX_{P2PY/Y2PY}_WhiteNoise.xml

• The data was processed with the scripts : 

ITMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGL2/Scripts/itmx_L2_diag.m

ETMX : /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL2/Scripts/etmx_L2_diag.m

The HEPI and ISI are locked at EndY.  SUS is being stopped down and ACB staging/prep is ongoing for installation.

These will be running continuously for the next week or two (part of portable RGA assembly/Y1 accumulation data collection).

With Jim needing to connect In-Vac cables to feedthrus today, I wanted to update the EY TMS Cable Table (mainly to show recent change of swapping damaged D1000223 cable with D1000225).  All of this follows the BSC10 Cable Routing Configuration (D12000111) & is in the following ICS Assy Load.

While I certainly appreciate the acumen of Stefan and Sheila on all things interferometeric, I showed yesterday in 10580 that HEPI did not move.  That said I do understand not always being able to catch all alogs that go in, I'm sure I'm very behind in my reading there too.

A couple things, that was not a glitch in HEPI, it was a trip condition that lasted for ~1.5+ hours.  I'm not sure how to figure out exactly what caused this trip in HEPI but the trend would suggest it is the last time this HEPI tripped and the MEDM says it was SUS.

I see ISI target changes on Tuesday and Thursday on stage1 timed with the HEPI Trips--likely model restart and ??  I suspect Stage2 sees this too.  This certainly will regulary impact alignment if it is recurring.  I think Sebastian must look through this closely and propose preventive measures here.

While I certainly appreciate the acumen of Stefan and Sheila on all things interferometeric, I showed yesterday in 10580 that HEPI did not move.  That said I do understand not always being able to catch all alogs that go in, I'm sure I'm very behind in my reading there too.

A couple things, that was not a glitch in HEPI, it was a trip condition that lasted for ~1.5+ hours.  I'm not sure how to figure out exactly what caused this trip in HEPI but the trend would suggest it is the last time this HEPI tripped and the MEDM says it was SUS.

I see ISI target changes on Tuesday and Thursday on stage1 timed with the HEPI Trips--likely model restart and ??  I suspect Stage2 sees this too.  This certainly will regulary impact alignment if it is recurring.  I think Sebastian must look through this closely and propose preventive measures here.

In addition to realigning the TMS, I also moved ETMX, ITMX, PR3, PR2 and IM4 tonight. 

I initially aligned the straight shot to ISCT1 using TMS and the baffle diodes, then PR3 for the camera spot.  Then I locked the cavity and tried engaging WFS.  I was able to engage PIT DOF1 and YAW DOF 1, and although the error signals were eventually brought to zero, the cavity build up dropped compared to the hand alignment.  The spot position also moved away from the spot on the camera that I had centered the single shot beam to.  I tried engaging PIT DOF2, but the gain was set to 0, and has been for a few days. I tried a gain of 1, which was bad, and a gain of 0.1 which seemed to have no impact. 

I gave up on the WFS and alinged the cavity by hand.  By moving TMS in pitch I was able to get the cavity build up to 800 counts again, so I decided to abandon WFS for tonight and go on to locking COMM.  The ALS_XARM guardian now has states for WFS. 

I was able to lock COMM using the guardian, and it was stable tonight with high gain ( I mean that the lock didn't drop unless I did something).  The noise measured by the linearize error signal is a bit worse tonight, 200Hz.  The first higher order modes were resonanting at the frequency were we though we had found the 00 mode last night.  I found the 00 mode at -5990Hz, and tweaked up the alingment using IM4 and PR2. 

Right now IM4 is at PIT -3077 YAW -5707 PR2 at 445 YAW at -383.1  I didn't save these using the IFO align screen in case the red team wants to restore their alignment from this morning using the current saved offsets. 

I did save TMSX, ETMX, ITMX and PR3.

After I restarted the corner beckhoff machine, the timing system did not come back.  I has an error on Corner Master A, Fanout 15, VCXO control voltage.

I've installed tilt decoupling on:

- ST1 BS

- ST2 ITMY

I've started working on ST2 ETMX & ITMX but haven't finished yet. I'll kkep going as soon as I have access to the platforms.

For the curious ones, you can find the DTT templates with the results of the tilt decoupling into the SVN:

/ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/<CHAMBER>/Data/Transfer_Functions/Measurements/

Stefan briefly mentioned in his alog last night that something happened with HEPI that caused them to realing etmx and TMSX

Today I tried to check the TMSX alingment using the baffle PDs, and found them 25 urad away from the saved positions  (I've saved new posoitions for both PDs and the aligned state).  For the record the positions were:

PD1 202.9 P -232 Y PD4 272 -293.8 saved

PD1 204.3 P -207 Y PD4 274 P -269 today aligned 238.15 -237.9

I've attached a screen shot of the CPS positions, after a glitch in HEPI stage 1 move by 10 urad, and stage 2 by about 15 urad in RZ.  According to Sebastian the total yaw the TMS would see will be the sum of these, so the ISI move explains the required move of TMS.

J. Kissel

Following the same procedure outlined in LHO aLOGs 9453 and 9079, I balanced the coils on the PUM stage of H1 SUS ITMX. The final balanced gains in the L2_COILOUTF bank are

H1 SUS ETMX
Channel     Balanced COILOUTF Gain
L2 UL            +0.909
L2 LL            -0.965
L2 UR            -1.035
L2 LR            +1.099

The precision to which we could balance the coils was limited by the really windy day ground motion, but we believe the obtained values are good to within +/- 0.5%.

This balancing has reduced the L3 P and Y caused by a L2 pringle excitation at 4 [Hz] by
   DOF                  Reduction Factor @ 4.0 [Hz]
    P                          > 14.6      (peak below the noise, and totally incoherent)
    Y                          > 10.1      (peak below the noise, and only ~45% coherent)
The attachment shows the result from which these values were obtained, comparing the optical lever ASD at 4 [Hz] driven from L2 at the same amplitude for both balanced and unbalanced configurations.

J. Kissel, C. Ramet, S. Biscans, B. Lantz

While grabbing data for the windy day today, I found that the temporary T240 that has installed at the X end station (see LHO aLOG 9758) was not being read out by the channels H1:ISI-GND_ETMX_{X,Y,Z}_DQ, and therefore not stored in the frames as expected. I found that the bug was in the ISI's front-end model where the channels on which the T240 were coming in were piped into the spigots for the "A" STS right off of the ADC, where it should be piped into "B." Check out D1400077 for more details and detailed redlines to both the analog wiring diagram and Simulink front-end wiring diagram. Finally, I've filled in the STS2CART matrix such that the T240 is now properly piped into the ground sensor correction path.

 

Mitchell and I got one more set (Pier 1, NW) of HEPI Actuators installed.  We ran into a problem though with the tilted tripod bar running into the Sensor Holster and locking up losing adjustablility.  I've noticed the closeness of this before but had never heard of a problem from LLO HEPI experience.  Anyway, we could not adjust the position to center the sensor without jamming/tilting the holster and locking it into position.  So we've taken the holster off and will mil it down a bit to give it some more clearance.  Definitely an issue to watch for during commissioning incase we incounter problems when adjusting Sensor Zero.  See attached sketch for idea of problem.  Who'd a thunk 30mils clearance would never be too little?

I tried running tf's on ETMY last night, but was foiled by my lack of understanding of the ETM sus overview screen (see Jeff's log # somethingorother). After SUS finished up alignment, I went down and unlocked the ISI to try again. After several hours of fruitless DTT tf's I'm giving up for now. I went down this morning and fiddled with the cables some, we tried several quad configurations (normal damping, increased pitch damping and all off), but have only managed to get worse, not better. The best guess we have right now is that maybe TMS is causing the badness (they are unplugged and can't damp at all) , but it doesn't seem a good guess because they weren't damped on the test stand (I think). More digging tomorrow, Arnaud wants the chamber for tonight.

For context, the attached DTT shows one degree of actuation and 3 associated sensors. Each curve  should kind of look like the red trace, make a peak(s, 3 seems normalish for this chamber) @ 1hz , then a valley @2.5hz, then another peak(s) @ 5hz. The extra notches at 2, 4 and 9.5 hz are "bonus", or maybe "bogus".

LVEA Laser Hazard

08:43 Justin – Working on IOT2R table
09:27 Betsy, Travis, & Jason - End-Y working on ETM-Y alignment
09:30 Jax – End-Y working on table
09:30 Andres – LVEA SUS test stand working on BOSEMs
09:30 PSL Status is good. All parameters are OK
10:30 Rick & Chris – Working in H2-PSL enclosure 
10:45 Rick – Craning items over beam tube
11:17 Karen – Finished cleaning at HAM4 and HAM5 area
11:44 Andres – Out of SUS Test Stand 
13:06 Karen – Going to End-Y
13:30 Hugh & Mitch – HEPI work at HAM4
14:50 Karen – Finished cleaning at End-Y
15:03 Patrick – Going to Mid-Y 
15:46 Patrick – Back from Mid-Y
16:00 Hugh & Mitch – Finished in LVEA