Displaying reports 62161-62180 of 77270.Go to page Start 3105 3106 3107 3108 3109 3110 3111 3112 3113 End
Reports until 09:17, Wednesday 10 December 2014
H1 SEI (CDS, DetChar)
krishna.venkateswara@LIGO.ORG - posted 09:17, Wednesday 10 December 2014 - last comment - 09:16, Thursday 11 December 2014(15529)
BRS tilt subtraction is improved

K. Venkateswara

After the changes to the way BRS is used at ETMX, detailed in 15497, tilt-subtraction shows significant improvement. Attached files show ASD plots from 40k seconds of data from last night, when winds were barely a few mph at ETMX.

The first plot is in angle units.  The blue line shows the ground seismometer output, the green shows the raw BRS output and the red curve shows the new tilt-subtracted super-sensor output. The roll-off at 5 mHz is due to the high-pass filter but most of the other difference is from the new tilt-subtraction. This is also clear in the coherence plot shown below - the coherence between the super-sensor and the T240 is less than the coherence between the T240 and BRS. The BRS ref is shown in cyan.

The tilt-subtracted super-sensor is tilt-free and reliable till ~30 mHz or so. Why is this important? For one thing, it can be used to do sensor-correction to Stage 1 of the BSC-ISI, while keeping tilt-reinjection at a minimum. This has the effect of reducing the microseism, which is a big problem at LLO and will be a problem here as well. This was shown recently in 15498.

Non-image files attached to this report
Comments related to this report
krishna.venkateswara@LIGO.ORG - 09:16, Thursday 11 December 2014 (15552)

Some data from last night when winds were at an incredible ~5 mph! :)

Images attached to this comment
Non-image files attached to this comment
LHO General
patrick.thomas@LIGO.ORG - posted 09:08, Wednesday 10 December 2014 (15530)
Morning meeting notes
Seismic:
Evaluation of tilt correction on all platforms as available

Suspensions:
Dan H. working on OMC tip/tilt

CDS:
Cabling for illuminators

Optical levers:
Installation of weights on optical lever piers

Facilities:
Contractors will be pouring concrete tomorrow. Access to the Y arm will be restricted until Monday morning.

3IFO:
Next to last BSC ISI is in its container, ready for exchange of containers
H1 AOS
david.barker@LIGO.ORG - posted 08:22, Wednesday 10 December 2014 (15528)
CDS model and DAQ restart report, Tuesday 9th December 2014

model restarts logged for Tue 09/Dec/2014
2014_12_09 10:45 h1susetmy
2014_12_09 10:46 h1iscey
2014_12_09 10:47 h1iscey
2014_12_09 10:48 h1susetmx
2014_12_09 10:49 h1iscex

2014_12_09 10:54 h1dc0
2014_12_09 10:56 h1broadcast0
2014_12_09 10:56 h1fw0
2014_12_09 10:56 h1fw1
2014_12_09 10:56 h1nds0
2014_12_09 10:56 h1nds1
2014_12_09 12:04 h1dc0
2014_12_09 12:04 h1fw0
2014_12_09 12:04 h1fw1
2014_12_09 12:04 h1nds0
2014_12_09 12:04 h1nds1
2014_12_09 12:07 h1broadcast0

Beckhoff:

C1PLC1 10:36 12/9 2014

C1PLC2 10:36 12/9 2014

C1PLC3 10:36 12/9 2014

X1PLC1 10:36 12/9 2014

X1PLC2 10:56 12/9 2014

X1PLC3 10:36 12/9 2014

Y1PLC1 10:36 12/9 2014

Y1PLC2 10:55 12/9 2014

Y1PLC3 10:36 12/9 2014

no unexpected restarts. Maintenance day. SUS and ISC model changes at end stations, with associated Beckhoff changes. Two supporting DAQ changes.

Conlog frequently changing channels list attached.

Non-image files attached to this report
H1 ISC
kiwamu.izumi@LIGO.ORG - posted 01:50, Wednesday 10 December 2014 - last comment - 18:34, Monday 22 December 2014(15526)
PRMI locked on sidebands, did OMC scan

Dan, Kiwamu,

We locked the PRMI on the sidebands to assess the current recyclying gains. The result will be posted later.

 


We did the initial alignment sequence to get back to a good global interferomter alignment. One thing I have to note is that I had to touch PR3 in yaw by 2 urads in order to recover a high RF power in ALS COMM. It is now back to 3 dBm in the monitor. Also this gave a good spot position on the ALS X camera as it was clipping before I moved PR3. The clipping seems to be fixed now on the camera. I aligned TMSY, ETMY and ITMY using the green light with a hope that they still represent a good IR alignment. After going through all the alignment sequence, the ALS DIFF beatnote came back to a high RF power of about 0 dBm. So I think the global alignment came back to as good as before.

The PRMI was locked very easily by setting LSC_CONFIGS to PRMI_sb_OFFLOADED. Then we aligned the OMs and did OMC scans in order to evaluate the recyclying gains. The data is now under some analysis. After the OMC scan, we attempted to lock the PRMI on the carrier, by simply flipping the sign of the PRCL control sign. We tried different gain settings MICH which uses REFL45Q, but did not get good lock tonight. So, we still don't know the carrier recycling gain.

Comments related to this report
kiwamu.izumi@LIGO.ORG - 02:26, Wednesday 10 December 2014 (15527)

We locked the PRMI on carrier. The carrier recyclying gain was measured to be 35 at highest. However, since the alignment was not perfect, it probably would go up. To be continued.

After playing with the gain settings, we eventually became able to lock the PRMI on carrier. However the alignment was not stable to keep it locked with high build-up. I think this needs more study to understand what is going on. Anyway, so far, the highest buidl-up in POPAIR_A_LF we had tonight was about 3.5x104 uW. When the simple MICH without power-recycling was locked, POPAIR_A_LF was about 30 uW. Assuming that there is no mode-mismatch and Tp=0.03, we get a recycling gain of 3.5x104 / 30 * Tp = 35. 

LSC settings:

  • set LSC_CONFIGS to PRMI_SB_OFFLOADED
  • flip the PRCL control sign so that the PRCL_GAIN is -11
  • switch the sensor for MICH from REFL45 to AS45Q with an input matrix element of 1.
  • set LSC-MICH_GAIN to -100.
  • flip the sign of POPAIR_B_RF18_I in the trigger matrix so that it locks when RF18 is negative.
daniel.hoak@LIGO.ORG - 13:00, Thursday 11 December 2014 (15557)

Attached are the OMC scan results for a PRMI sideband lock, compared to a scan from a single-bounce beam.  The first plot shows the results of three single-bounce scans and three PRMi scans (100 second ramps of PZT2); the second plot has averaged the traces.  The PRMI data appears to be shifted upwards compared to the single-bounce data, by about 1V in the PZT2 output.  We expect some drift and hysteresis in the PZT, but the single-bounce data was taken immediately after the PRMI lock, and a shift of this size is...surprising.

Using Kiwamu's expression from alog:14532, I calculate the PRC gain of the 45MHz sideband to be about 11.8 or 14, depending on which sideband peak you use.  I think this is lower than we expect.  The PRMI sideband lock was quite wobbly with a lot of angular motion, we might get a more robust measurement by locking the OMC to a particular mode and maximizing the transmission.

Here is a table of peak heights:

Sideband Freq. Single-bounce data PRMI Data
-45 0.31 3.98
-9 0.17 2.45
9 0.17 0.22
45 0.31 4.70

With a Schnupp asymmetry of 9.5cm the gain, for example for the upper 45MHz sideband, is (4.7/0.31) * (0.03*0.5*0.5) * (1/sin(2*pi*0.095*5*9100230/c)**2) = 13.9.

Images attached to this comment
kiwamu.izumi@LIGO.ORG - 18:34, Monday 22 December 2014 (15794)

Just for a book-keeping purpose:

Two weeks later from this entry, we have measured the recycling of the carrier with the ASC loops fully engaged. We measured it to be 45 (see alog 15793).

H1 ISC
eleanor.king@LIGO.ORG - posted 22:50, Tuesday 09 December 2014 (15525)
Scattering measurements comparing X-arm and Y-arm test masses

Kiwamu, Dave O, Paul, Elli

 

We used the digital cameras looking at the test masses to compare scattering from ITMx and ITMy and from ETMx and ETMy.  From our measurements, it appears that ETMy scatters more light than ETMx.  The two ITMS scatter comparable ammounts of light.

 

We took photos of each of the test masses with the IR locked in each arm and the green beam misaligned.  Examples of the kind of scattering we saw are attached in scatteringPRofileExamples.jpg.

 

We then estimated the total light scattered onto each camera.

-The camera aperature was opened to maximum for each camera.  The exposure time was chosen to be the same for both ITMs and both ETMS, and the exposure was chosen so very few (<5) pixels were saturated.  When we did this, we noticed two particularly bright smears on ETMy.  We had to reduce the ETM exposure level right down before these two spots stopped saturating the camera.

-We also took background images of each optic with no IR or green beam in the arms at the same exposure level.  We also subtracted the noise floor from the images.  The images with background and noise removed are attached in backgroundAndNoiseRemoved.jpg.

-Finally the pixel value for each image was summed over the entire image to give a value proportional to the ammount of light scattered onto the camera.  These pixel sums are: (the matlab code for calculating these is attached.)

  Pixel Sum
ETMx 0
ETMy 36

 

  Pixel Sum
ITMx 43
ITMy 25

At a super low exposure time of 200microseconds, we detected no light scattered off of ETMx, but we can still see an appreciable ammount of light comming off of ETMY.

The ITMs were imaged at 10000microseconds exposure time, and the amount of scatter we see is much more comparable than for the ETMs.

Images attached to this report
Non-image files attached to this report
H1 ISC (CDS, ISC)
evan.hall@LIGO.ORG - posted 22:23, Tuesday 09 December 2014 - last comment - 09:33, Wednesday 10 December 2014(15524)
Prep work for arm ringdown measurements

Alexa, Evan

We want to perform some ringdown measurements of the arms (particularly the Y arm) in order to corroborate our other loss measurements. We intend to use the technique described by Isogai et al., which has already been carried out at LLO (see, e.g., LLO#13748, LLO#11727).

In preparation, we've done the following work:

Tomorrow we'll try to take some data and analyze it.

Comments related to this report
alexan.staley@LIGO.ORG - 09:33, Wednesday 10 December 2014 (15531)

In case someone wants to use Chris's script in the future it can be found here: /ligo/home/alexan.staley/Public/RingDown/RoboRingdown.py

H1 CDS
patrick.thomas@LIGO.ORG - posted 20:12, Tuesday 09 December 2014 (15523)
Conlog restarted
It appears that Conlog had stopped running at around 15:16. The following error was logged:

Dec  9 15:16:54 h1conlog2 conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Out of range value for column 'value' at row 1: Error code: 1264: SQLState: 22003: Exiting.
Dec  9 15:16:55 h1conlog2 conlog: ../conlog.cpp: 331: process_cas: Exception: boost: mutex lock failed in pthread_mutex_lock: Invalid argument Exiting.

I've restarted it for now.
H1 AOS
krishna.venkateswara@LIGO.ORG - posted 17:52, Tuesday 09 December 2014 (15521)
LLO Sensor correction filter turned on at ETMX

J. Warner, K. Venkateswara

As detailed in LHO alog 15511 and SEI alog 645, the BSC chambers would benefit from LLO's "0.43 Hz only" sensor correction filters for X and Y

Jim and Rich had installed the filters previously. I turned them on at ETMX along X and Y. The gains were set to ensure clear subtraction on the CPS channel relative to the ground by a factor of ~10 near 0.43 Hz as seen in the attached plots.

Non-image files attached to this report
H1 PSL (ISC, PSL)
sudarshan.karki@LIGO.ORG - posted 16:52, Tuesday 09 December 2014 (15519)
ISS Second Loop in IMC Gaurdian

Dan H, Sudarshan K,

The ISS second loop automation is implemented in the IMC guardian. This included a slightly modified script from alog 15164.

We added ISS_ON as a requestable state and CLOSE_ISS and OPEN_ISS as intermediate state to move  in and out of  it. The sticky issue is setting the REF_SIGNAL voltage to get the OUTPUT to zero. We do that  by looking at the sum of the in-loop-pd signal. This takes several seconds and occasionally will sets the initial ref signal little off from the optimal value because of the in-loop-pd transient.  We need to find a better way of doing this for our future iterations.

There are some failure modes in the CLOSE_ISS mode which will trigger jump transitition to OPEN_ISS. This can result in a never ending loop if the script keeps trying and failing to close the loop. In this case you can change the requested state to LOCKED and it will return to LOCKED when it fails the next time.

Images attached to this report
LHO VE
kyle.ryan@LIGO.ORG - posted 16:45, Tuesday 09 December 2014 (15520)
Restored Y-end purge air to nominal (1 psi) configuration
Had been modified to accommodate Rai W.'s needs for ionizer test
LHO VE
kyle.ryan@LIGO.ORG - posted 16:44, Tuesday 09 December 2014 (15518)
Finished replacement of Corner Station chilled water booster pump
Had started this job yesterday -> Should run Corner Station purge air compressor with new booster pump before purge air is needed to confirm cooling is adequate
H1 General
jeffrey.bartlett@LIGO.ORG - posted 16:11, Tuesday 09 December 2014 (15516)
Add Dust Monitors
Installed dust monitor (Location #2) at BSC10 for the ETM-Y Vent. Filiberto and Manny worked cabling issues with the location #2 dust monitor dropping network connection. Will run the dust monitor for 24 hours and check its operation. 

Installed a dust monitor near the door at HAM-1(Location #1) for the vent of HAM-1 next week. Will monitor and establish a base line ahead of opening the chamber.   
LHO General
corey.gray@LIGO.ORG - posted 15:59, Tuesday 09 December 2014 (15507)
Ops DAY Summary

Day's Activities

 

EY Dust Monitors both appear to go INVALID

H1 CDS
david.barker@LIGO.ORG - posted 14:08, Tuesday 09 December 2014 (15515)
CDS Maintenance Summary

h1guardian0 restart: DB and PT

We rebooted the h1guardian0 machine for testing. As last week, the guardian nodes restarted automatically with no problems but conlog died. We were closely watching the conlog MEDM screen and saw all the numbers increment wildly for a second and then the IOC died. Patrick noticed that in both cases, it was one of the new guardian USRMSG channels which logged an exception (these are the 100 byte array PVs). During this morning's conlog channel reconfiguration we removed these channels from conlog, and will test with another guardian reboot next Tuesday.

End Station SUS and ISC changes: DS and DB

Daniel installed new SUS and ISC models in both end stations. The DAQ was restarted to support these changes (new INI files for ISC).

Beckhoff Code Changes: DS and DB

Daniel installed new Beckhoff code in all three locations. The following INI files were changed: h1ecatc1plc1, h1ecatx1plc[1-3], h1ecaty1plc[1-3]. The DAQ was restarted.

Code With Local Mods:

the attached files show front end and guardian files with local modifications which require commits to svn.

Partially loaded filter modules: DB

The load-all-coefficients button was pressed for the following models: h1suspr3, h1sussr3, h1susomc, h1susitmx, h1lsc, h1sushtts

Files without controls group access: DB

Shared files on the /opt/rtcds/userapps, /opt/rtcds/lho/h1/target and /ligo/svncommon which were not writable by controls group were modified to be so.

INI and Foton Checks: DB

Running DAQ INI files and filter module foton files were passed through inicheck and foton. Reports attached. Reminder we have DAQ channels with mixed case in their names.

DMT DAQ: DB

Verified all DMT channels are in the DAQ and there is no duplication

Non-image files attached to this report
H1 SEI
hugh.radkins@LIGO.ORG - posted 11:52, Tuesday 09 December 2014 - last comment - 12:14, Wednesday 10 December 2014(15510)
STS2 Grund Seismos A & C put into igloos this morning

These instruments have just been sitting on thefloor with no insulation so Krishna Jim and I got them under Trillium igloos.  We had trouble with the internal Cable routine and may revisit to improve that.

Comments related to this report
krishna.venkateswara@LIGO.ORG - 16:46, Tuesday 09 December 2014 (15517)

The seismometers may be a little better - I've attached a pdf showing the X, Y, Z channels on the HAM2, HAM5 and ITMY seismometers and the coherence between them.

ITMY in particular looks significantly different and shows much less coherence than it probably should. It also refuses to zero out very well when the 'zero' button is hit on the control unit for the seismometer.

An overnight measurement may be a bit more illuminating.

Non-image files attached to this comment
krishna.venkateswara@LIGO.ORG - 12:14, Wednesday 10 December 2014 (15535)

J. Warner, H. Radkins,  K. Venkateswara

The data from last night looks about the same. Plots are attached. The ITMY_Z and HAM2_Y channels look odd at low frequencies. The rest look reasonable.

Jim, Hugh and I checked the U,V,W outputs from the seismometers and confirmed that they were within the +/- 2 V spec described in the STS-2 manual.

Non-image files attached to this comment
H1 SEI (IOO, ISC)
kiwamu.izumi@LIGO.ORG - posted 20:13, Monday 08 December 2014 - last comment - 10:44, Wednesday 10 December 2014(15499)
HAM2 ISI sensor correction turned off

Evan, Krishna, Alexa, Dan, Kiwamu,

At some point in this evening, we noticed that the IMC kept dropping its lock for some unknown reason. It turned out that the HAM2 ISI sensor correction was amplifying seismic at 0.3-ish Hz which resulted in a large drive in MC2 to keep it locked. So we turned the sensor correction off for now. This fixed the issue.

Even though the MC2 coil DACs were not saturating, somehow the motion was big enough to unlock the IMC. It is still unclear why it could unlock. Anyway, after turning off the sensor correction, the amont of drive in MC2 suspension reduced by a factor of 5 or so and IMC became able to stay locked. With the sensor correction on, the MC length was moving approximately +/- 5 um according to IMC_X displacement monitors. We don't know what changed in the HAM2 ISI sensor correction as it has been running fine for a while recently. Only thing we immidiately noticed was that the seismic freq-limited RMSs were pretty high in 0.1-0.3 Hz and 0.03-0.1 Hz bands in this evening. The attached is a time series of the IMC_X signals when we did a simple test of turning on and off the sensor correction in the HAM2 ISI. Since we were a bit rough for turning on and off the correction, it gave a transient when switcing it, but one can still see that when the correction was running, the IMC_X signal increased by roughly a factor of 5.

Images attached to this report
Comments related to this report
evan.hall@LIGO.ORG - 19:42, Tuesday 09 December 2014 (15522)

According to Valera, we should have sensor correction on for both HAM2 and HAM3, or for neither.

If both of them have sensor correction on, the MC benefits from the reduced seismic noise. If both of them have sensor correction off, the MC benefits from some amount of common-mode rejection in the ground motion between HAM2 and HAM3. If only one or the other has sensor correction on, then the MC is fully exposed to the ground motion, since one platform moves with the ground and the other is isolated.

valery.frolov@LIGO.ORG - 10:44, Wednesday 10 December 2014 (15532)
For PRC/SRC the sensor correction has to be ON on all HAMs (as BSCs are already inertial due to low blend) to avoid the full ground motion impression on these cavities.
H1 SUS
jeffrey.kissel@LIGO.ORG - posted 11:30, Monday 04 August 2014 - last comment - 13:44, Tuesday 09 December 2014(13184)
H1 SUS ITMY Dorrs On TFs -- TOP looks good, lower stages discrepant with model by factor 2
J. Kissel, A. Pele

Ran transfer functions over the weekend, to assess if the SUS is free after first contact removal and closing doors. While the top stages look great, this is the first time I've been exposed to a factor of two missing between model and measurement for the lower stages. While we don't expect the model to account for the dynamics of the reaction chain (which is why we see a whole bunch of "extra" features in the main-chain dynamics), we don't expect an overall gain mismatch. Arnaud informs me that this is true of every QUAD except one stage of one (including L1 SUS ITMY). 

No reason to pull doors off, but we should figure out where this discrepancy lies. And also , we should develop a model of the lower stage dynamics which include both chains.
Non-image files attached to this report
Comments related to this report
brett.shapiro@LIGO.ORG - 11:51, Monday 04 August 2014 (13185)
The reaction chain will displace about the same amount as the main chain for the lower stage measurements. Could this explain the factor of two gain relative to the model, since the OSEMs measure the difference between chains?
arnaud.pele@LIGO.ORG - 12:00, Monday 04 August 2014 (13187)

HA !

jeffrey.kissel@LIGO.ORG - 12:07, Monday 04 August 2014 (13188)
Plausible. Let's model it to find out!
brett.shapiro@LIGO.ORG - 15:30, Monday 04 August 2014 (13199)
I added a feature to 

 .../SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/generate_QUAD_Model_Production.m

to compile a quad model with both main and reaction dynamics to predict what the L1 (UIM) and L2 (PUM) OSEMs will measure. See the results in the attached pdf. The overall gain is still not 100%, but is definitely closer. Pitch has some obvious mismatch due to known extra stiffness on the reaction chain (from OSEM cables I think).


The update to generate_QUAD_Model_Production.m has instructions commented into the header for using the new combined main/reaction model. I copy those instructions here.

"
You can compile multiple chains simultaneously, to predict what the UIM 
(L1) and PUM (L2) OSEMs will measure. To use this feature, sandwich the 
string '_with_' between the two build types you want to use, main chain 
1st, reaction chain 2nd. For example, for a monolithic ITM use

   buildType = 'fiber_with_thincp'
 
The combined model will only combine the outputs for the UIM (L1) and
PUM (L2) L, P, and Y DOFs, to reflect the OSEM measurements. The inputs
however will be shared for all the seismic inputs as well as the UIM and
PUM L, P, and Y DOFs. The indices for inputs and outputs are unchanged.
 
  Caution: there is no error or warning for non-physical combinations. For
  example, 'fiber_with_fiber' will compile OK, but the results will be
  inconsistent with reality.
"
Non-image files attached to this comment
arnaud.pele@LIGO.ORG - 13:44, Tuesday 09 December 2014 (15514)

For future reference, attached are osems spectra from before the swap comparing top mass damping on / off 

Non-image files attached to this comment
Displaying reports 62161-62180 of 77270.Go to page Start 3105 3106 3107 3108 3109 3110 3111 3112 3113 End