Displaying reports 68221-68240 of 77131.Go to page Start 3408 3409 3410 3411 3412 3413 3414 3415 3416 End
Reports until 18:24, Thursday 09 January 2014
H1 CDS
david.barker@LIGO.ORG - posted 18:24, Thursday 09 January 2014 (9193)
h1boot and cds overview modified for new h1susauxasc0 model

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.

H1 SEI
hugh.radkins@LIGO.ORG - posted 18:22, Thursday 09 January 2014 (9190)
ETMX Elevated ISI T240 Noise source w/HEPI Tilt found. Glitches...maybe

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.

Images attached to this report
H1 AOS (AOS)
thomas.vo@LIGO.ORG - posted 18:14, Thursday 09 January 2014 (9192)
H1 ETMX Optical Lever Calibration
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

Non-image files attached to this report
H1 SUS
jeffrey.bartlett@LIGO.ORG - posted 16:51, Thursday 09 January 2014 (9189)
M2 & M3 Open Light Values for SR2
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
 
LHO General
dale.ingram@LIGO.ORG - posted 16:34, Thursday 09 January 2014 (9187)
Thursday summary
** 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
H1 SUS
jeffrey.bartlett@LIGO.ORG - posted 16:21, Thursday 09 January 2014 (9184)
Phase 2b TFs & Power Spectra for H1-SR2
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.  
Non-image files attached to this report
H1 ISC (ISC)
sheila.dwyer@LIGO.ORG - posted 16:21, Thursday 09 January 2014 (9185)
als laser noise eater, tms input beam polarization

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.

LHO VE
kyle.ryan@LIGO.ORG - posted 15:57, Thursday 09 January 2014 (9183)
Soft-cycled GV7 for craning of HAM4 doors + misc.


			
			
LHO General (CDS, PEM)
patrick.thomas@LIGO.ORG - posted 15:41, Thursday 09 January 2014 (9182)
started IOC for corner station weather station
Started in 'screen' on h0epics2.
H1 SUS
betsy.weaver@LIGO.ORG - posted 13:41, Thursday 09 January 2014 (9181)
ITM03 (H1-ITMx) first ear bonded sucessfully

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.

H1 CDS (SUS)
david.barker@LIGO.ORG - posted 12:19, Thursday 09 January 2014 (9179)
h1susitmy has hardware watchdog control part added

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.

H1 ISC (IOO, ISC)
stefan.ballmer@LIGO.ORG - posted 11:54, Thursday 09 January 2014 (9178)
PR3 alignment range that allows visibility to HAM1
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





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.
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
H2 ISC
keita.kawabe@LIGO.ORG - posted 17:22, Friday 08 June 2012 - last comment - 16:28, Thursday 09 January 2014(3077)
ALS power budget (mostly done by Alberto)

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.

Comments related to this report
keita.kawabe@LIGO.ORG - 16:28, Thursday 09 January 2014 (9186)

References: D1201457, E1000870, E1000669, E1000652, E1000425, C1103229

On a closer look, there is two E1000669 "IR HR, Green HT" mirrors (M4 and M7) in the green TMS path. Transmission of these is 98.6% according to the vendor measurement.

5% transmission is really 5.0% measured (E1000870), high reflectors are measured to be really high reflective (E1000652, E1000425).

Also, though there's no reflectivity measurement for TMS telescope silver mirrors, various vendos offer "protected silver" coating reflectivity data in tiny tiny plots, and Thorlabs data looks as if the reflectivity is 97% rather than 98 for 532nm, Newport quite similar, CVI looking lower. None of these three vendors are used for TMSY, we used two Edmund optics (the reflectivity data I wasn't able to find) and two custom optics coated by a coating vendor in California, but it sounds safe to assume that the reflectivity is 0.97 or lower per silver mirror.

ETMY uses ETM04 (C1103229) which has a ITM HR with a transmission of 1% for 532nm.

Including 98.6% transmission twice, 95% reflection once and 97% reflection four times,  we have:

0.986^2 * 0.95 * 0.97^4*0.99 = 0.82 single path, or

(0.986^2 * 0.95 * 0.97^4)^2 = 0.67 double path for TMS itself.

Including 99% ETM, we have 0.66 total.

Double path was measured to be 61%, so there's still 5% discrepancy but this might easily be the silver mirror reflectivity.

If we put everything into the silver mirror, its reflectivity should be 96% per mirror.

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