Displaying reports 68481-68500 of 77130.Go to page Start 3421 3422 3423 3424 3425 3426 3427 3428 3429 End
Reports until 13:09, Thursday 12 December 2013
H1 PSL (PSL)
sheila.dwyer@LIGO.ORG - posted 13:09, Thursday 12 December 2013 (8927)
ref cav transmission

Robert, Chris, Sheila

Chris and Jamie got the script that records the psl camera centroids working on the gaurdian machine, it generates epics channels H1:PSL-FSS_TRANS_CENTROID_PIT, H1:PSL-FSS_TRANS_CENTROID_YAW, H1:PSL-PMC_TRANS_CENTROID_PIT, H1:PSL-PMC_TRANS_CENTROID_YAW with the position of the centroids in pixels.  For now the script is in userapps/isc/h1/scripts/AnalogCameras.

You need to give it the username and password for the cameras when you call the script.

For the ref cav trans, pitch has not really moved since Nov 22 (when chris first got this script running) (pit is  119, yaw is 177)  https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=8707

So, it seems like this position has been fairly stable.  the ref cav alignment always drifts up (meaning that the beam is high compared to the cavity position based on the refl camera), so if this was due to the cavity moving we would have seen some difference in the trans centroid position.  It seems like the beam moving, not the cavity. 

With Robert we looked at the long term drift, which doesn't seem to be correlated with temperature.  (the 20 minute fluctuations are). 
In the last several weeks we have had two times when the transmitted power was stable for several day stretches, both of those were times when the transmitted power was 1.2V.  (perhaps we need to realign the AOM and the cavity periscope each time we realign to get the power that high). 

I've attached a trend of the ref cav trans PD and the threshold over a long period of time.  It seems like this has never been stable, but the resonant threshold was set to be much lower than the normal value for most of the time since the PSL came online.

It may be that no one has cared about the stability of the reference cavity transmitted power until we started using it for ALS. 

 

Images attached to this report
H1 IOO (IOO)
cheryl.vorvick@LIGO.ORG - posted 12:47, Thursday 12 December 2013 (8926)
IMC Beam Centering Measurement - raw gains found to minimize excitation peak

- Kiwamu, Cheryl

I ran excitations to get gains that we turn into beam centering.  Here are the raw gains, and the minimum peak amplitudes.  Most peaks were reduced to the noise level at 0.05e-12, but two were not, and those are MC3 pitch (0.12), and MC1 yaw (0.3).

 

Beam Centering Measurements: 12/12    
     
  P2L/Y2L gain smallest peak amplitude
MC1    
P -0.90 0.05
Y 0.60 0.30
     
MC2    
P -1.30 0.05
Y -1.00 0.05
     
MC3    
P 0.85 0.12
Y -1.10 0.05
H1 SEI
hugh.radkins@LIGO.ORG - posted 12:09, Thursday 12 December 2013 (8925)
WHAM2 HEPI Shifts during pump down/unlock

I've confirmed with raw data (Inductive Position Sensors) that the shift in HAM2s HEPI position is pretty small.  The worst individual local shift is <0.2mm and in cartesian basis we see a 170um +Y shift & a 50urads +Rz; the other translations & rotations are less.  These comparisons are from during the HEPI Locked period (30 Oct to 3 Dec) during which the IMC crew had ok conditions, and, the current controlled position.  When HEPI trips and the position is not controlled, the shift is still quite minor and sometimes for the better.  In the case when it is not, it is still less than a factor of two.

H1 DAQ (CDS)
david.barker@LIGO.ORG - posted 11:33, Thursday 12 December 2013 (8924)
DAQ reconfigured for latest Beckhoff slow channels

Sheila and Dave

Sheila updated the Beckhoff EDCU INI files for PLC[1,2,3] for C1 and EX. I added them to the DAQ and restarted the DAQ. Note that the EX Beckhoff is a new addition to the DAQ, the master file was modified accordingly.

H1 INS (INS, SEI)
jim.warner@LIGO.ORG - posted 09:45, Thursday 12 December 2013 - last comment - 10:52, Thursday 12 December 2013(8921)
ETMX HEPI Unlocked

Hugh and I realized this morning (a little late, sorry) that the ISC crew were doing alignments that could be affected by HEPI, which was still locked after chamber close-out. I went down this morning and unlocked, hopefully I wasn't too disruptive. Will attach trends in a bit.

Comments related to this report
jim.warner@LIGO.ORG - 10:52, Thursday 12 December 2013 (8922)INS, SEI

Trends for ETMX HEPI IPS. Not great, but pump down is also going on right now, so these numbers look kind of normal. First 8 plots are local, the remaing are "global" in nm, although there are some doubts about their calibration. Looks like the platform lowered ~.1 mm (which makes sense, because HEPI only has Z axis stops that can only push up on the foot), with much smaller movements in the other axes.

Images attached to this comment
H1 ISC
keita.kawabe@LIGO.ORG - posted 07:35, Thursday 12 December 2013 - last comment - 10:53, Wednesday 18 December 2013(8919)
HAM1 REFL path: done for the moment (Jamie, Kiwamu, Keita)

Yesterday we adjusted WFS1 path.

From some calculations by myself and Lisa Barsotti plus an assumption that MC mode cannot be THAT bad, I concluded that there isn't that much of a difference between moving everything to optimize VS moving only RM2.

Detailed analysis will follow shortly, but it seems like we're at not too bad, not too good position and if that turns out to be the case we'll stop here.

For example X waist location is already perfect, the waist size is smaller than ideal and the Gouy separation seems to be 114 deg or some such. Y should be worse.

Before calling it a day, we looked at RMs and one of the eddy current dampers for RM2 was significantly closer to the mirror holder than everything else, so it was backed off.

Comments related to this report
jameson.rollins@LIGO.ORG - 10:53, Wednesday 18 December 2013 (9002)

We took pictures of the REFL path in HAM1 while we were in there, including overview pictures the RM mirrors, the WFS sled, and the REFL PDs.  These have been uploaded to ResourceSpace:

H1 IOO (IOO)
cheryl.vorvick@LIGO.ORG - posted 07:22, Thursday 12 December 2013 (8918)
Forensics on HAM2, HAM3, and the IMC alignment

After finding a big shift in MC1 pre-pump down to post-pump down, I looked at more optics on both HAM2 and HAM3.

MC3 moved -34urad in pitch and 106urad in yaw.  This is consistent with being tilted the same direction as MC1.

PRM shifted -63urad in pitch and 365urad in yaw.  This is consistent with tilted the same direction as MC1.

IM4 shifted 98urad in pitch and 82urad in yaw.  This is consistent with tilted the same direction as MC1.

Other optics on HAM2 are ignored due to having a shift in position that negates their pitch and yaw signals for this purpose.

The shift in all of these optics show that the +X,+Y corner of the HAM2 optics table is lower than it was before pump down.  This is a problem, since this results in the fixed mirror behind MC1 sending the beam low on MC2 by about 5mm.

PR3 has a signal, X/Y_DEMOD_SIG that seems to come from an optical lever.  I didn't get a chance to really look into this signal and how it is generated and calibrated.  It shows a shift in pitch that's small, but a shift in yaw of 40 counts(?).  This supports a rotation of the HAM2 table, though I can't put a real number on it at this time.

I also looked into the IMC WFS and compared a good IMC alignment from September to the lock yesterday.   Were all optics table positions restored after pump down to their previous positions, the position of the IMC optics would be very similar.  In the current situation, with the WFS drive optimizing the IMC, the optimal positions for MC1 and MC3 have change a lot.

MC1 has changed position by 674urad in pitch and 958urad in yaw.  This corresponds to a change in pointing at 16m of 11mm in pitch and 15mm in yaw.

MC3 has changed position by 723urad in pitch and 1030urad in yaw.  This corresponds to a change in pointing at 16m of 12mm in pitch and 17mm in yaw.

MC2, in comparison, has changed position by 124urad in pitch and 173urad in yaw.  This corresponds to a change in pointing at 16m of 2mm in pitch and 3mm in yaw.

Punchline:
HAM2 - very different than before pump down - tilted and possibly rotated
HAM3 - changed, but may be tolerable long term to the IMC

H1 AOS
arnaud.pele@LIGO.ORG - posted 23:15, Wednesday 11 December 2013 (8917)
RM2 TFs unchanged

After some work was done on RM2 to tune the position of the eddy current dampers, a quick dtt tf was ran, but doesn't seem to have changed the mysterious double resonance in yaw. (see the previous TF of H1 RM2 in the 3rd page of this pdf from alog 8725). Comparison results will be plotted tomorrow.

H1 SUS
arnaud.pele@LIGO.ORG - posted 22:36, Wednesday 11 December 2013 (8916)
dac monitor channels fixed for BSFM/QUAD/HLTS/HSTS

[Dave Arnaud]

Following Stuart's change at LLO after he discovered a bug in the display of some DAC channels (see alog entry 10101) the directories containing the SUS_CUST_${sus_type}_DAC_MONITOR.adl files have been svn updated, and now displaying the right signal.

H1 SUS
angus.bell@LIGO.ORG - posted 17:38, Wednesday 11 December 2013 (8915)
End Y monolithic welding preparation
Angus, Travis, Gerardo & Alastair
Removed test mass from suspension and stored in tin. Small chip on the side of one of the ears on this mass due to brush against structure on removal. After TCS had replaced ring heater we put the production ETMY into the suspension ready for full alignment tomorrow morning. We checked the profile of the fibres in storage and the following ones all look to have approximately the same stretch. S1301759,  S1301769, S1301770, S1301771, S1301772 & S1301767. The first 4 of these are now at at end-Y ready for use.
 
H1 TCS (TCS)
mindy.jacobson@LIGO.ORG - posted 16:22, Wednesday 11 December 2013 - last comment - 16:27, Thursday 12 December 2013(8913)
Replaced ETM-Y Ring Heaters
Addressing "Bug 256", the pair of ring heaters installed at the pilot ETM were from Production Lot #1. These have been replaced with a pair of ring heaters from Production Lot #3. See also T1300463-v17.
Comments related to this report
greg.grabeel@LIGO.ORG - 16:26, Wednesday 11 December 2013 (8914)TCS
Pictures of the replacement.
Images attached to this comment
mindy.jacobson@LIGO.ORG - 16:27, Thursday 12 December 2013 (8930)
NOTE:
Only the upper and lower ring heating segments were replaced.
All associated cables remain the same; hence, there should be no grounding concerns.
H1 ISC
alexan.staley@LIGO.ORG - posted 16:03, Wednesday 11 December 2013 - last comment - 09:36, Thursday 12 December 2013(8912)
Fiber power from MSR to EX

(Alexa, Sheila)

 

1. Input to MPC @ MSR: 280uW

2. Output of MPC @ MSR: 240uW

3. To EX @ MSR: 170uW  

4. Output @ EX: 45uW

5. Outpt of patch panel on ISCTEX: 42uW

6. On table @ fiber output: 25uW

 

This is not good. sad. The loss between 2&3, 3&4, 5&6 are much higher than expected. 

Comments related to this report
cyrus.reed@LIGO.ORG - 09:36, Thursday 12 December 2013 (8920)

If you are measuring the total power, then you might try mandrel wrapping the fiber at the input; it may be that you are measuring power from higher modes in the fiber that will dissipate rapidly in the first part of the fiber chain.  A mandrel wrap will dissipate these modes early, so you will be left with a more accurate reading of the power that will propegate the full length of the fiber.  This will be particularly true for 1064nm light; singlemode fiber is designed for 1310nm - for 1064nm, it will behave more like multimode fiber.

Even so, something looks particularly bad with the insertion loss for the jumper between the polarizer box and the patch to EX (2&3 in your list).  That's probably a bad or dirty fiber.

LHO General
gerardo.moreno@LIGO.ORG - posted 15:51, Wednesday 11 December 2013 - last comment - 10:48, Friday 09 May 2014(8911)
Ops Shift Summary

(Corey, Gerardo)

- Transition of LVEA to laser safe, Justin.
- Chris W, ASC/LSC front end code, per WP4335.
- TCS clean up, Thomas.
- Sheila and Alexa, X-End station, ALS table work.
- Travis, Alastair, Angus, and Gerardo, to Y-End TM removal from monolithic.
- Filiberto, to LVEA, camera work, ITMY installation.
- Transition of LVEA to laser hazard, Justin.
- Restart of epics gateway.
- Mindy and Thomas, Y-End, TCS ring heater installation.
- Travis, Alastair, Angus, and Gerardo, to Y-End, ETM12 install in monolithic.

Comments related to this report
margot.phelps@LIGO.ORG - 10:48, Friday 09 May 2014 (11802)
ETMy Ear Bonding Information:
Ear 58 was bonded to side S3 on 9/23/2013.
Ear 68 was bonded to side S4 on 9/24/2013.
H1 ISC
alexan.staley@LIGO.ORG - posted 15:29, Wednesday 11 December 2013 (8910)
Mode Matching ISCTEX

(Alexa, Sheila)

We were able to get the retro-reflected beam off of ETMX back onto ISCTEX. We adjusted the PIT and YAW offset of the TMS to the following values:

YAW: -297 (originally -224)

PIT:  -3 (originally -13)

ETM offsets remain off

We have improved the mode matching between the outgoing and reto-reflected beam by moving ALS-L7 two inches toward PZT 2. By looking at the iris with a viewer, the shapes and sizes of both beams look good and matched.

 

We have also aligned the retro-reflected beam onto the PD.  

H1 SUS
arnaud.pele@LIGO.ORG - posted 15:24, Wednesday 11 December 2013 (8909)
SUS RM2

DTT templates for RM2 tfs have been modified to match with the model update. They are called and lived in :

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/RM2/SAGM1/Data/2013-11-23_2212_H1SUSRM2_M1_WhiteNoise_${L/P/Y}_0p1to50Hz.xml

LHO VE
john.worden@LIGO.ORG - posted 15:19, Wednesday 11 December 2013 (8908)
X End pumpdown

The turbo was spun up around noon  - setpoints have been restored, vent and purge valves have been closed, and the system is stable. Pressure is currently 1.5 e-5 torr.

H1 ISC
alexan.staley@LIGO.ORG - posted 18:52, Tuesday 10 December 2013 - last comment - 14:22, Friday 13 December 2013(8898)
ALS Fiber Distribution Chassis S1202528

As noted in alog6341, the gain on the Dual PD Amp board was set to 30dB (photo 1). I have reduced the gain to 10dB (photo 2). However, I still see saturation at 10V in the external PD monitor. Tomorrow I will try reducing the gain to 0dB.  

Images attached to this report
Comments related to this report
alexan.staley@LIGO.ORG - 11:14, Thursday 12 December 2013 (8923)

I have reset the internal PD gain to 30dB (since we were never saturating there), and set the external PD gain to 0dB.

For the external PD:

Transimpedance = 20kOhm

Responsivity = .268A/W

Power @ ext PD = 0.93mW (w/ a drift of 7% of the ref cav alignment)

Gain = 0dB

Volts = (resp) x (power) x (trans) x (gain) = 5V

alexan.staley@LIGO.ORG - 14:22, Friday 13 December 2013 (8948)

...Ignore above calculation for external PD...

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