Displaying reports 68241-68260 of 77131.Go to page Start 3409 3410 3411 3412 3413 3414 3415 3416 3417 End
Reports until 08:39, Thursday 09 January 2014
LHO VE
kyle.ryan@LIGO.ORG - posted 08:39, Thursday 09 January 2014 - last comment - 09:32, Thursday 09 January 2014(9162)
Soft-cycled GV20 for OPLEV-to-viewport work (resubmission, original entry was accidently deleted)
Nominal running of GV20 motor for 4 minutes and 16 seconds did not result in effective isolation of X-end (see attached)  

Additional running of motor was required to get full O-ring contact as follows:  

Ran motor 4 minutes 16 seconds - stop - accelerate to 500 rpm - stop - accelerate to 300 rpm
Images attached to this report
Comments related to this report
kyle.ryan@LIGO.ORG - 09:32, Thursday 09 January 2014 (9174)
This entry pertains to activity on 1/7/2014
H1 SEI
hugh.radkins@LIGO.ORG - posted 08:12, Thursday 09 January 2014 - last comment - 10:15, Thursday 09 January 2014(9172)
ETMX/ITMX ISI Commissioning/performance progress

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.

Comments related to this report
hugh.radkins@LIGO.ORG - 08:41, Thursday 09 January 2014 (9173)

Here is 30 minutes second trend of the T240 glitch that tripped the ISI.  It is like most all the others, pretty much just out of the blue.  BTW, I'm pretty sure the Isolation was just level1 as well.

Images attached to this comment
jim.warner@LIGO.ORG - 10:15, Thursday 09 January 2014 (9176)INS, SEI

New safe.snaps were generated this morning for ITMX ISI. I also checked the same matrices at ETMX and they at least agree with what is currently supposed to be there.

H1 ISC (COC)
sheila.dwyer@LIGO.ORG - posted 21:25, Wednesday 08 January 2014 - last comment - 16:41, Thursday 09 January 2014(9171)
apparent ETM reflectivity for green

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

Comments related to this report
sheila.dwyer@LIGO.ORG - 12:33, Thursday 09 January 2014 (9180)

Looking at the data from last night more carefully, with the ITM misaligned we get 12675 counts on refl B LF, the top of the fringe is around 17500 counts and the bottom of the fringe is 15300 counts.  The attached plot shows the ratio of the top of the fringe to the prompt reflection, and the bottom of the fringe to the prompt reflection, with predictions assuming the ITM R=99% and no other losses. Both the top and the bottom of the fringe are consistent with the ETM R=73%, not so different from the 76% on the nebula page.  The other ETMs on the nebula page (including livingston) are similar.  It seems like at least several of our ETMs are out of spec (spec was 3%-15%) , the cavity fringing is not terribly far off from what we would expect given the measurements from LMA.  Also, estimating this using the fringes means that our measurement is sensitive to mode mismatch and misalingments, and we don't know how our mode matching or alingment are right now. 

If the ITM has a reflectivity of 99% (we don't have a measurement of this, but that was intended) and the ETM 76%, we would get a cavity finesse of 22, and the reflected power on resonance would be about 93% of the reflected power on resonance.  The cavity pole would be at 840 Hz.  This will probably mean that the performance of our PDH lock is worse, but this may not be a serious problem since the noise of the PDH lock wasn't limiting us in HIFO Y.  

The efficency of the TMS table still seems to be worse than expected.  Assuming the ETM has R=76% , our measurement of the reflection off the ETM indicates that we loose 50% of our power in the TMS, or 70% of the power on each pass through the TMS.  At end Y (alog 3077) Keita measured 61% of the injected green light returning to the table, so this was at worse 78% efficiency each pass through the TMS.  

 

Summary:

the ETM is out of spec, but this was reported by LMA in the coating documentation, and pretty much explains the low finesse cavity we have. 

TMS efficiency is worse at end X than at end Y for reasons we do not know yet.  

Non-image files attached to this comment
keita.kawabe@LIGO.ORG - 16:41, Thursday 09 January 2014 (9188)

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=3077

Look at the above alog entry from OAT and its followup below that.

I was wrong about silver mirror reflectivity (I looked at Thorlabs, Newport and CVI catalog and they're more like 97% or less rather than 98%), and this 1% difference makes a huge impact because we have four mirrors double path so it's 8 reflections.

Anyway, all included, TMS itself is supposed to have 67% double path efficiency.

During OAT the double path efficiency was supposed to be 66% including the 99% ETM but was measured to be 61%, but note a large uncertainty regarding the protected silver mirror coating. If we put this discrepancy in the silver coating reflectivity, it is 96% per silver coating.

One thing to note is that we changed the coating vendor of some (but not all) of the TMS optics, we now use Newport protected silver mirrors for F1 instead of Edmund for all but H1 TMSY.

H1 SUS (CDS, SEI)
jeffrey.kissel@LIGO.ORG - posted 19:09, Wednesday 08 January 2014 - last comment - 09:40, Thursday 09 January 2014(9169)
SUS Hardware Watchdog Testing
J. Kissel, R. Bork, B. Abbott, D. Barker, F. Clara, A. Sevigny

Satisfied with a few days of debugging and testing a single chassis of the new Hardware Watchdog System on the H1 DAQ Test Stand, we have installed a similar chassis in the SUS BSC123 rack, and hooked it up to the H1 SUS ITMY M0 sensors. We have deliberately *not* connected any of the trip signals (either to the SEI or SUS actuators) while we characterize the RMS trigger system. In addition to the hardware, we've installed temporary configurations of the h1iopsusb123 and h1susitmy models, in which

- h1iopsusb123: Unfortunately, neither analog or digital readbacks of the RMS calculated by the board are exposed in any way. Instead, we've installed a mock RMS system to replicate the RMS logic that is performed inside the hardware watchdog itself, using the raw ADC values as inputs. Though the changes have been made to the model, it has not yet been compiled, installed or restarted, since the green team were still actively searching for beams and needed ITMX up all afternoon. Hopefully we can install tomorrow morning.

- h1susitmy: the status bits of the hardware watchdog *are* digitized via a binary input chassis, and fed into spare channels of the already present Contec BIO card. Similarly, the remote control reset bit are spit out of the same card, through a binary output chassis, to the SUS hardware watchdog. As such, for the status bits, we needed to add a few new connections inside the BIO_DECODE block, which are turned into a bitword and fed into a new EPICs readback channel, H1:SUS-ITMY_HWWD_STATUS.

Once we get the readback installed, we'll run the ITMY chamber in various configurations of isolation and excitation, to determine a good value for the RMS threshold. The test cases we plan to use are:
- Ambient (no actuation from any layer)
- SUS Undamped, ISI Damped, HEPI Position Loops
- SUS Undamped, ISI Damped, HEPI Position Loops (With large alignment offset)
- SUS Damped, ISI Damped, HEPI Floating
- SUS Damped, ISI Damped, HEPI Driven (Normal level TFs)
- SUS Driven (LOUD White Noise TF), ISI Damped, HEPI Floating
- SUS Damped (With large alignment offset), ISI Damped, HEPI Floating
- SUS Undamped, ISI Driven (LOUD White Noise TF), HEPI Floating
- SUS Undamped, ISI Floating, HEPI Driven (LOUD White Noist TF)
These should give us a good feel for the most quiet and most loud situations for the M0 OSEMs. Based on these results, we'll make an assessment of where we want to set the threshold.
Comments related to this report
jeffrey.kissel@LIGO.ORG - 09:40, Thursday 09 January 2014 (9175)CDS
J. Kissel, J. Warner

After ensuring all seismic isolation and suspension systems were safely ramped down, I re-compiled, re-installed the h1iopsusb123 front end model. After which, I killed all processes running on that front end, h1susitmx, h1susbs, and h1susitmy, restarted the h1iopsusb123 process, and restarted all the suspension processes. I then finally restored damping on SUS ITMX, ITMY, and BS, and restored the alignments of ITMX and BS to what they had been set before I got started.

Both temporary configurations of the h1susitmy.mdl and h1siopsusb123.mdl have been committed to the userapps repo.
H1 ISC (ISC)
stefan.ballmer@LIGO.ORG - posted 19:04, Wednesday 08 January 2014 - last comment - 19:08, Wednesday 08 January 2014(9168)
X arm locking mysteries

Alexa, Sheila, Daniel, Keita, Kiwamu, Stefan

 

We tried to lock the x-arm today, but we stumbled over a couple of mysteries.

- For the initial alignment we first pointed TMS onto ITM baffle PD1, and found TMS PIT=107, YAW=-207. This was -2urad, -4urad less in PIT, YAW than the previous alignment measurements (alog 9126), so we subtracted these values from the subsequent ones. We repeated this for the ITM using the ETM baffle PD. The ITM was PIT=57, YAW=-78.

- With both optics aligned we get about 18000 counts on REFL_B_LF. Surprisingly though, misalignment of ITMX (yes ITM) dropped this to 12000 counts

- We do get a PDH signal of about 5V out of the Imon demod. However, with the cavity just slightly misaligned, we still get a sinusoidal PDH signal of about 2V. We are not sure why, but are afraid it could be some scattered light.

- The PDH loop does lock temporarily, but the arm motion was slightly too large -- the sus pro-team is working on this.

- Next we misaligned PR3 in yaw by -150urad (from -272urad to -422urad). This put the straight through beam nicely on the Swiss cheese baffle.

- We also noticed a ghost beam to the right of the straight shot. It moves with ITMX and CPX, which pretty much nails down what it is.

- There is also a 2nd copy of the straight though and ghost beam visible to the left of the POP hole in the Swiss cheese baffle.

Comments related to this report
stefan.ballmer@LIGO.ORG - 19:08, Wednesday 08 January 2014 (9170)
Here are Keita's rough alignment numbers, as well as two screen shots of the Swiss cheese baffle.
Images attached to this comment
H1 ISC
sheila.dwyer@LIGO.ORG - posted 18:42, Wednesday 08 January 2014 (9167)
Overall Offset Alignments

Images attached to this report
LHO General (SUS)
douglas.cook@LIGO.ORG - posted 17:47, Wednesday 08 January 2014 - last comment - 11:19, Thursday 09 January 2014(9166)
Fiber Pulling Machine updates and Alignments
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.
Comments related to this report
betsy.weaver@LIGO.ORG - 11:19, Thursday 09 January 2014 (9177)

Attached is a picture of the top bracket of what would be a fiber holder stuck in the top stage of the fiber puller, when in fact it should have released (hence Doug's hand prepared to catch it during the photo shoot!).  This sticky mating is what Doug fixed.  Currently Travis and Giles are pulling fibers.

Images attached to this comment
H1 AOS
thomas.vo@LIGO.ORG - posted 17:34, Wednesday 08 January 2014 (9165)
Fine Alignment of HIFO-X OptLevs
Now that the alignment of the cavities is roughly good, I aligned the ITMX, PR3, HAM2, HAM3, and ETMX optical levers to their respective optics/HAMs.  

It's relevant to note that the connector of the controller for the translation stages broke, we were able to re-solder the wires but the connection is very fragile.  I'll just have to be careful when moving it around but it'd be best to have a system where we're not constantly unplugging and plugging in delicate wires every time we want to re-align the pointing.
H1 SEI
hugh.radkins@LIGO.ORG - posted 17:02, Wednesday 08 January 2014 (9157)
WBSC9 ETMX T240 noise w/ HEPI Offset

Related to the continuing study of the subject problem, I repeated the measurement at ETMx.  When compared to a similar tilt applied to ITMY (see 9139), the HEPI Tilt increases the noise level on the T240 significantly more at ETMX.  See the first 4 hour plot below.  The upper right plot is the HEPI tilt first off then on and then off again.  The vertical axes of the T240 are pretty much unaffected.  And depending on the orientation of the pod, some axes are more affected than others.

I had a thought, if we were running the HEPI Actuators into their stops, we could be shorting HEPI to ground and affecting the T240.  So, I did the -12000 offset, back to zero and then went to -13000.  See the second 30 minute plot with the offset 'ramps' in the upper right.  Notice the other graphs with the 8 HEPI position sensors showing an increase in position at the -13000 offset relative to the -12000.  So I think this says the Actuators are not running into anything at the -12000 count level...

Images attached to this report
LHO General
gerardo.moreno@LIGO.ORG - posted 16:35, Wednesday 08 January 2014 (9164)
Ops Shift Summary

- Justin to LVEA, laser safe transition.
- John to LVEA, soft close GV6 and GV8, per WP4380.
- Bubba and crew to LVEA, remove HAM01 door, per WP4379.
- Mitchell and Andres to LVEA, AOS/ACB assembly work.
- Corey to MX, store items.
- Filiberto and Aaron to Y-End, inspection of installation.
- Justin to LVEA, supervise locksmith.
- Luis and Frank to X-End, PEM cable work.
- Justin to LVEA, laser hazard transition.
- Thomas to LVEA, alignment of OLs.
- Mitchell to LVEA, AOS/ACB assembly work.
- Dave from CR, lots of reboots per WP 4382.
- Karen and Chris to LVEA, HAM4 cleanroom, clean area per WP4384.
- Filiberto and Aaron to X-End, Install GigE camera on A1-C, port VP5, per WP4386.

H1 SUS
mark.barton@LIGO.ORG - posted 15:19, Wednesday 08 January 2014 (9160)
SUS Guardian fix

Mark B. and Kiwamu.

Yesteday afternoon, Kiwamu reported that the MC2 guardian was giving an error in line 104 the SUS.py script. This was a call to a method from sustools.py in the definition of the ALIGNED state:

self.optic.lockGainWrite(1.0,[],[], [P,Y])

This could never have worked - all arguments to lockGainWrite other than the first are keyword arguments, and the non-empty list should be of strings. I changed it and a similar instance (line 120) to

self.optic.lockGainWrite(1.0,chans=['P','Y'])

That solved the initial problem and exposed a second: there was no file ^/sus/h1/burtfiles/h1susmc2_misaligned_offsets.snap .

I created one by copying h1susmc2_aligned_offsets.snap and manally putting in new offsets suggested by Kiwamu.

I committed the fixed SUS.py and added and committed everything else in the ^/sus/h1/burtfiles and ^/sus/common/guardian directories.

H1 ISC
keita.kawabe@LIGO.ORG - posted 12:16, Wednesday 08 January 2014 (9155)
POP and ALS handling in HAM1

References: aLOG 6683, https://dcc.ligo.org/L1200282, https://dcc.ligo.org/T1200470, https://dcc.ligo.org/D1000313-V9

Attached shows the relative position of ALSX, ALSY and POP (from L1200282) together with two top periscope mirror profiles (equidistant from three beams and centered on ALSY, the latter is supposed to be the current configuration). Green and red circles show the beam diameter obtained from T1200470 and D1000313-V9 (V10 doesn't have the beam profile information).

With the "centered on ALSY" configuration POP is close to the edge of the mirror. Today HAM1 incursion team will move everything such that periscope and downstream will be equidistant from three beams though we have only the ALSX for the moment,. They'll also try to find POP in HAM1 again with the new alignment.

Non-image files attached to this report
H1 ISC (ISC)
stefan.ballmer@LIGO.ORG - posted 11:58, Wednesday 08 January 2014 - last comment - 12:59, Wednesday 08 January 2014(9156)
arm initial alignment work
I installed the following IPC links:

ASC to ISCEX:    PZT1X_PIT PZT2X_PIT, PZT1X_YAW PZT2X_YAW  (all four are being received)
ASC to ISCEY:    PZT1Y_PIT PZT2Y_PIT, PZT1Y_YAW PZT2Y_YAW  (all four are being received)
ASC to SUSTMSX:  TMSX_PIT, TMSX_YAW  (not being received yet)
ASC to SUSTMSY:  TMSY_PIT, TMSY_YAW  (not being received yet)

(links for ASC to ETMs and ITMs were already installed.)


checked in
h1asc.mdl:  SVN revision 6769
h1iscex.mdl: SVN revision 6770
h1iscey.mdl: SVN revision 6770

We are still getting some IPC errors.
Comments related to this report
jeffrey.kissel@LIGO.ORG - 12:59, Wednesday 08 January 2014 (9158)CDS, INS, SUS
J. Kissel, S. Ballmer, D. Barker

I've completed the install of the new IPC communication between the ASC front-end model and the TMS and HTTS models for green / REFL alignment control. This required 
- (as Stefan mentions above) Adding RFM IPC parts to the ASC model to send to the end-station SUS computers,
H1:ASC_TMSX_PIT_SUSTMSX
H1:ASC_TMSX_YAW_SUSTMSX
H1:ASC_TMSY_PIT_SUSTMSY
H1:ASC_TMSY_YAW_SUSTMSY
- (as Stefan *didn't* mention above) Adding SHMEM IPC parts to the ASC model to send to the HTTS core on the same front-end
H1:ASC_RM1_PIT_SUSHTTS
H1:ASC_RM1_YAW_SUSHTTS
H1:ASC_RM2_PIT_SUSHTTS
H1:ASC_RM2_YAW_SUSHTTS
- Modifying the ASC and OAF IOP model parameters to turn on the RFM capability (Set "rfm_dma=1")
- Installing all of the above mentioned channel into the respective receiver models, and hooking them up to the already-present place holders in the ISC input bus creator,
h1sustmsx --> H1:ASC_TMSX_PIT_SUSTMSX, H1:ASC_TMSX_YAW_SUSTMSX
h1sustmsy --> H1:ASC_TMSY_PIT_SUSTMSY, H1:ASC_TMSY_YAW_SUSTMSY
h1sushtts --> H1:ASC_RM1_PIT_SUSHTTS, H1:ASC_RM1_YAW_SUSHTTS, H1:ASC_RM2_PIT_SUSHTTS, H1:ASC_RM2_YAW_SUSHTTS
- Re-compiling, Re-installing, Re-starting, and Re-storing all of the following models:
h1iopasc0
h1iopoaf0
h1asc
h1sustmsx
h1sustmsy
h1sushtts
All of the modified models mentioned above have been committed to the userapps repository.

Taking down H1 SUS TMSX naturally trips the watchdog on HPI and ISI ETMX, so Hugh and I made sure to ramp down all offsets before getting started. After restoring, Hugh has brought up HPI ETMX and ISI ETMX, and I've restored the alignment of both SUS ETMX and SUS TMSX. No one is using the RMs just yet, so they have not been restored -- and indeed, they do not yet have a good safe.snap, so they will need a complete restore from scratch. Bummer.
LHO VE
john.worden@LIGO.ORG - posted 10:22, Wednesday 08 January 2014 (9154)
End Station Pumpdown and transition to BT

The attached plot shows the XEND pump down and transition to BT operation. 30 days are shown.

Over the Christmas break we operated on the main turbo only. On Jan 6 the transition to the main ion pump and 80K pumps was made.

After isolating the main turbo the beam tube valve was opened for HIFO X  work.

You can see that the the pressure has come to ~4e-8 torr in the BSC chamber (pt510). The two gauges on the 80K pump and the beam tube are both below 2e-8 torr.

In summary the transition from turbo only to final configuration has bought us slightly more than a factor of 10 improvement in pressure.

 

The LVEA transition is shown in this alog https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9119

 

For reference, guidance related to opening to the beam tube is here: https://dcc.ligo.org/LIGO-T1300802

Images attached to this report
H1 ISC
kiwamu.izumi@LIGO.ORG - posted 08:06, Wednesday 08 January 2014 - last comment - 08:09, Wednesday 08 January 2014(9150)
PRX locking: PR2 and PRM aligned to the newly aligned PR3, some optics oscillating in pitch

After the alignment of PR3 (see alog 9146), I aligned PR2 and PRM to get PRX flashing with the infrared light. The resultant alignment sliders are shown in the attached.

I could lock PRX quite smoothly, but it seems that some optics are oscillating in pitch by a non-negligible amount. Due to this, the intracavity field spatially wobbles by almost its beam size in pitch according to the CCD camera attached on BS's chamber. In this condition, the intracavity power observed by the POP_A QPD fluctuates more than 10%. We need to identify which optic is the culprit by using the oplevs and witness sensors. It seems to me that it is hopeless to try locking PRMI without improving this wobbliness.

Images attached to this report
Comments related to this report
kiwamu.izumi@LIGO.ORG - 08:09, Wednesday 08 January 2014 (9153)

An additional note:

The spatial beam motion was observed by introducing an intentional misalignment in ITMY and BS to let the ITMY reflection beam hit the BS baffle which is monitored by the BS CCD camera.

H1 AOS
thomas.vo@LIGO.ORG - posted 20:08, Tuesday 07 January 2014 (9152)
ETMX Optical Lever
Greg G, Thomas V

I tricked Greg into helping me and we successfully installed and aligned the ETMX optical lever; it will need to be calibrated it next but that will not require the closure of a gate valve. At the first shot of alignment, there was some clipping on the edge of the viewport so we had to modify the transmitter mount which took a bit more time than I expected.  

Note:
We adjusted the height of the receiver pylon to line up the viewport to the optical lever enclosure, but this did not take into account what will be needed for the photon calibrator receiver so we might have to revisit this in the future.
LHO VE
kyle.ryan@LIGO.ORG - posted 16:09, Monday 23 December 2013 - last comment - 14:53, Wednesday 08 January 2014(9068)
2500 L/s ion pump controller settings
For the record, the following are the nominal values used for the large ion pump controllers (listed in the order queried by the MultiVac firmware Flow 7):  

Torr
Spare
7000V 
200mA 
200watt 
Protect
10mA 
STEP 
5000V 
1.0 x 10-3amps 
3000V 
4.0 x 10-5amps 
(StPt 1) 1.0 x 10-5torr (not used?) 
(StPt 2) 1.0 x 10-6torr (not used?) 
1.0 x 10-10 
1.7 x 10-9 
8.0 x 10-7 
2.0 x 10-4 
Comments related to this report
kyle.ryan@LIGO.ORG - 14:53, Wednesday 08 January 2014 (9159)
Correction:  

1 x 10-3 amps (should be) 3 x 10-3 amps
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