Displaying reports 69101-69120 of 77126.Go to page Start 3452 3453 3454 3455 3456 3457 3458 3459 3460 End
Reports until 15:23, Monday 28 October 2013
H1 TCS
jodi.fauver@LIGO.ORG - posted 15:23, Monday 28 October 2013 (8289)
SM2 Re-Clean
After serious searching (OSB Optics Lab twice, VPW) this morning, Greg and I were able to locate the cleaning fixtures shortly after lunch: they were still attached to some obsolete steering mirrors that were not stored with the bulk of the TCS parts. I carefully removed the tooling (Teflon disk, gussets, handle) from the old mirrors and put it on the new mirrors. This task was completed at about 3:15 PM. We will try cleaning the mirrors tomorrow.
H1 SUS
mark.barton@LIGO.ORG - posted 15:04, Monday 28 October 2013 (8287)
IM1 TF test

Commencing Matlab TFs on IM1 at 3:00 pm to debug new HAUX support in the script.

H1 SUS
arnaud.pele@LIGO.ORG - posted 14:42, Monday 28 October 2013 (8286)
SRM phase 2b results

Attached are damped and undamped top mass transfer function results taken last friday night for SRM phase 2b (test bench, surrogate glass mounted)

Undamped TF are matching the model, cf the first attachement. Damped TF are slightly different for longitudinal and roll (cf second attachement), which might be due to a discrepancy between the design gain and the medm one. Since the filters will be redesigned soon, there's nothing to worry about for now.

The last attachement shows a comparison between SRM phase 1b (staging building), the last phase 2b measurement, and PRM phase 2b back in february.

The only 2 differences seen are for the pitch DOF (5th page)

1) SRM gain at DC is slightly higher by a factor of ~1.3 compared to PRM

2) Phase 2b shows a slight increase of the longitudinal to pitch cross-coupling at 2.8Hz compared to phase 1b

Other than this results are good.

Travis will be centering the lower stages osems this afternoon in order to check the actuation chain, before closing phase 2b.

 

Note : SRM has the "side" osem, which drives the "transverse" DOF, on the opposite side as PRM. The gain for the side drive is then different, (+1), cf the picture attached as reference.

The new settings have been saved under the "safe" snapshot.

Images attached to this report
Non-image files attached to this report
H1 ISC (CDS, ISC, TCS)
sheila.dwyer@LIGO.ORG - posted 12:08, Monday 28 October 2013 (8285)
changes to corner plc2

I made changes to plc2 on h1ecatc1, adding variables and function blocks for the PLL boards and the FindResonance library, which can be used to automate the search for the VCO frequency offset needed to bring the arm cavity on resonance using ALS.  I did not make any changes to the system manager, this will need to be done for the PLLs once the corner 6 chasis arrives. 

Everything is in SVN. 

When I try to use the installation scripts, activate and run always fails for PLC3.  (TCS stuff)  However, I can go the PLC control, loggin and run and it seems to run fine.

H1 SEI
fabrice.matichard@LIGO.ORG - posted 22:43, Sunday 27 October 2013 (8284)
HEPI to ISI Tilt decoupling: MIMO Calculation
Continuing the work on HEPI to ISI tilt decoupling for HAM2, I found that MIMO calculations were necessary to properly account for the non negligible cross couplings and minimize all four tilt couplings mechanisms (X to RX, X to RY, Y to RX and Y to RY).

Also useful to highlights how unsymmetrical the tilt coupling behavior is (almost two orders of magnitudes??)

The document attached is a draft of a procedure accounting for the cross couplings.

The last pages show predicted/calculated results. The correction matrix will be implemented tomorrow and we'll take data to see whether this works as predicted.
Non-image files attached to this report
H1 SYS
robert.schofield@LIGO.ORG - posted 13:35, Sunday 27 October 2013 (8283)
Magnetic coupling to ITMY sensor channels

Summary: no coupling hot spots (e.g. coil drivers, satellite amps, or feedthroughs) were found in the OSEM systems; L4Cs were the coupling hot spots in HPI and ISI systems. Magnetic coupling to sensors was not high enough to be a problem in normal operation but is a problem for our large magnetic injections.  Cable coupling is worse for AOSEMs than BOSEMs.

Our magnetic coupling experiments suffer from our inability to rely on L4C, T240, BOSEM, and AOSEM channels to measure motion because of direct magnetic coupling to these sensor channels. I studied coupling to these channels, particularly whether there were local sites (e.g. to magnets in the sensors, or to feed-throughs) or diffuse (e.g. to cables) in order to help us interpret coupling results. 

The technique I used was to generate a global field (roughly the same over the entire system) with a distant coil and a local field at a slightly different frequency with a local coil. A magnetometer was set up at the tested location (e.g. a feedthrough) and the fields from both coils were adjusted to give equal amplitudes at the magnetometer (Figure 1). If the feedthrough was the dominant coupling site, then the peak from the local field would be comparable to the peak from the global field. If the local field made a much smaller peak in the OSEM channel than the global field did (as for the Figure 1 location) then the feedthrough could not be the dominant coupling site.

In addition to balanced magnetic fields, I also sometimes increased the local field to see how much leeway there was at the local coupling site. Figure 2 shows that coupling at the coil driver is lower than elsewhere even when the local field is much larger (good design!).

Results (good between 10 and 40 Hz)

SUS: I tested for local coupling at the chamber, the feedthroughs, the satellite amp, and the coil drivers. Coupling at each of these locations was small compared to global coupling, suggesting that the cable runs were the most important coupling sites. Unfortunately, the worst coupling was to the AOSEMs on the PUM, the closest OSEMs to the test mass. To see if there was a specific problem with the AOSEM cabling etc., I switched PUM AOSEM and UIM BOSEM cables at the BSC feedthrough, and the coupling was still high, so it is not because of a bad cable, etc. Tests of an isolated AOSEM and its in-chamber cabling indicated very low coupling, so it seems that the EMF generated in cables influences the AOSEM signal more than the BOSEM signal. For ITMY we are getting a coupling to the AOSEMs of as high as 0.05 m/T for a15 Hz field that is roughly uniform in the LVEA and ebay. The BOSEMs are lower by at least an order of magnitude.

ISI: Coupling to the L4Cs is greater than to the T240s or the GS-13s. It is good that they are only on the first stage. Coupling to the L4Cs dominates over cable coupling and ebay coupling. I am not sure what dominates in the T240 and GS-13 sensor channels because the coupling was so low.

HPI: the dominant coupling is at the L4Cs. 

Robert S., Richard McCarthy.

Non-image files attached to this report
H1 AOS
robert.schofield@LIGO.ORG - posted 13:32, Sunday 27 October 2013 (8281)
Views of and from ETMX for scatter evaluation

Summary: scattering evaluation photos of ETMX, the ACB, the cryobaffle and the p-cal periscope show no major problems.

Figure 1 shows approximately what the beam spot on ETMY “sees”. I use these photos to look for potential scattering problems; the camera is placed very close to the center of the optic where the beam spot will be. The flash mimics the wide-angle scattering of interferometer light from the beam spot and lights up regions that will retroreflect interferometer light back to the beam spot, where it can recombine with the main beam to produce scattering noise. Of course the technique is limited by different angular distributions of scattered IFO light and light from the flash, as well as by color differences, but it gives a rough idea. The camera is about 10 cm in front of ETMX, so it sees a little more through the hole in the baffle than the beam spot on the optic will. This is why you can see the baffle walls on either side of the baffle aperture. I think the actual view of the beam spot is just narrow enough that it doesnt see these baffle walls. The "H" at the middle is the sheet metal cover at the spool with an "H"-shaped aperture in it for IAS. The flash is reflecting off of this sheet metal cover. 

I dont see any terrible glints coming from the pcal periscope, though it reflects more than the cryobaffle behind it. I think the lower reflectivity of the cryobaffle is not needed here, but is needed for its twin baffles near the ITMs where the angle is smaller. The white spot at the right of center is one of the periscope mirrors, which is directing the flash to a reflective surface at the port. This is a reminder that we need to be careful about backscattering from the pcal boxes and other equipment at the ports.

Figure 2 is an approximation of what ITMX will see of ETMX. The camera is in the beam path and so the flash is reflecting off of the ETM. Of course the camera is a lot closer than the ITM, so the camera sees more through the baffle aperture of the region around the ETM than the ITM will see. The ETM is covered with first contact, which produces the irregular reflections. The view of everything, except the ACB, is blocked by the cryopump baffles. The ACB looks good, the light spots are the photodiodes. 

Images attached to this report
H1 SUS
robert.schofield@LIGO.ORG - posted 13:31, Sunday 27 October 2013 (8282)
Magnetic moment of blade spring with attached 2x6 mm magnet is too large

We removed the large eddy current damper magnets from the UIM blade spring in the quads, and there remains a question about whether we can use a small magnet to attach a tuned mechanical damper to the blade spring. I have measured the relative permeability of a blade to be greater than 6 (here), so it is possible that the blade spring will “amplify” the moment of the magnet. For this reason, I attached a magnet to the blade spring at the proposed location and measured the magnetic moment of the blade spring in my moment balance (Figure 1).

Adding the 0.013 J/T 2x6 mm magnet to the blade spring increased the moment of a single blade spring by 0.12 J/T in the beamline direction. The resulting displacement noise of the test mass from ambient fields acting on a single such blade spring would be about 3.1 e-20 m/sqrt(Hz) at 10 Hz (assuming 2e-11 T/ sqrt(Hz) ambient magnetic field).  For this reason, I think that we should not use 2x6 or 2x3 magnets on the blade springs without a cancelation scheme. As a comparison, the large magnets used by the BOSEMs have a moment of 0.72 J/T, but with all of the cancelations from orientation, I have estimated that the remaining moment (with no orientation errors) would be about 0.2 J/T (here). If there are no other ways of attachment, I can try cancellation schemes, but they may not be very successful because one of the magnets is in contact with the ferromagnetic material.

Images attached to this report
H1 SEI
fabrice.matichard@LIGO.ORG - posted 20:41, Saturday 26 October 2013 (8280)
what state the ISI should be in while working on HEPI tilt decoupling
We have often had the discussion about "what blend filtering the ISI should be in while working on HEPI tilt decoupling".

The first plot compares the response from "HEPI IPS" motion to "ISI GS13 motion" for two different configurations: "ISI damped" and "ISI isolated". The low frequency part of the transfer functions don't change, indicating that the tilt coupling ratio is unchanged.

The second plot compares tilt decoupling results for several blend configurations. The black line is the reference (no tilt correction). The exact same tilt-correction factor was used for all other measurements (for the records, the decoupling factor used was 7.0%, calculated from the measurement shown in the first plot).

This second plot shows that the tilt correction implemented works just as well for all blend configuration, which is really good news.
Images attached to this report
H1 SEI
fabrice.matichard@LIGO.ORG - posted 20:54, Friday 25 October 2013 (8278)
Model Changes Completed and restarted
1) IPC senders for ODC have been added in all 21 SEI models (thanks Ryan). See pic #1 for an example

2) I removed the IPC receivers for SUS offloading (ECR E1300578). An example is shown in pic #2 and #3.

3) Updated the STS library blocks for EX and EY. Moved the block and links to receive STS A signals instead of STS B to be consistent with LLO. See pic #4 and #5 for an example.

4) I re-compiled, installed and re-started all 21 models. They have been committed in the svn Rev (6069 for isi, 6068 for hepi)

5) After restart, all models WD safe values are now up to date. ISI_GND_EX test points match with what's coming from STS_B. IPC indicators in CDS screens went from red to green -> All modifications seem to function

6) Ryan modified the ODC MEDM screens and committed them and ran scripts to populate the EPICS fields in the ODC screens. 

7) I created new safe.snaps for all 21 models so that these EPICS variables in ODC screens will be set to the correct names at the next restart. Created the safe.snap symbolic links in target to point toward the userapps. The safe.snap files in the usearapps have been committed in the SVN


That should complete the current set of modifications on: 
- ODC
- WD safe values
- STSA -> STSB 
- IPC offloding removal




  

Images attached to this report
H1 SUS
arnaud.pele@LIGO.ORG - posted 19:28, Friday 25 October 2013 - last comment - 10:13, Thursday 31 October 2013(8279)
ETMX and SRM measurements

I will start transfer functions of top mass of main and reaction chain of ITMX phase 3a (in chamber, under vacuum) on computer opsws2 and top mass phase 2b SRM (test stand) on computer opsws0 from 8pm tonight.

Measurements will run until saturday morning. Please do not close those matlab sessions if you come over the week end.

The channel list used to get the data from the framebuilder (in generate_channel_list.m living in sus/trunk/Common/Matlabtools/SchroederPhaseTools) has been modified to match with the recent model upgrade of the QUADS. Since channels H1:SUS-${QUAD}_${L1/L2}_DAMP_${DOF}_IN1_DQ do not exist any more. They are now called H1:SUS-${QUAD}_${L1/L2}_WIT_${DOF}.
This is related to why we couldn't get data out of the frame for the ETMX on thursday
This is also related to why we couldn't see any good calibrated rotation signal with dataviewer on ETMX for the UIM and the PUM

Comments related to this report
arnaud.pele@LIGO.ORG - 10:13, Thursday 31 October 2013 (8333)

I ment ITMX in the title

H1 General
jeffrey.bartlett@LIGO.ORG - posted 15:58, Friday 25 October 2013 (8277)
Ops Summary
LVEA: Laser safe
Alarms: CDS frontends

HEPI Alignment at End-X
Richard – working on TMS-X computers
Jim W – Working on ITM-X

Ed Watt – removal of insulation in X-Arm enclosure
Sprague – Pest control at X2

09:14 Stefan restarting the IMC Model
09:30 Filiberto & Aaron pulling cables at End-X
09:40 Thomas & Mitch working on Cryopump baffle
10:00 Peter & Justin – Working in H2-PSL enclosure
10:20 Betsy & Travis – Checking cabling and Satellite box at BSC3
13:30 Dave – Recycled alarm handler to add channels for End-X   
    
H1 SEI (SEI, SUS)
hugo.paris@LIGO.ORG - posted 15:37, Friday 25 October 2013 (8276)
Compare local SVN Revision with Server

We have been looking for ways to figure out which SVN revision is in use on the workstations, and which revision is available on the server. The goal is to allow the commissioners to understand where they stand regarding the ongoing updates.
 

Charles and I came up with the following sequence using svn log. The whole subtlety of it is the use of: ^, which tell the svn log to look at the server, and not the working copy.

 

Details are shown below, with h1isihammaster.mdl as an example.

 

Note: There may be a better way to do this. We just thought this one would be good enough for now.

 

 

 

Check What Is Loaded On The Local Copy

 

controls@ligo-ops2:/opt/rtcds/userapps/release/isi/common/models$ svn log -l 5 isihammaster.mdl

------------------------------------------------------------------------

r5713 | jeffrey.kissel@LIGO.ORG | 2013-09-16 15:41:18 -0700 (Mon, 16 Sep 2013) | 1 line

 

committing new master models for HAM and BSC. include changes for science frame channels, ODC gain monitoring, and migraion of checker-script to the front end - not yet tested at LASTI

------------------------------------------------------------------------

r5044 | hugo.paris@LIGO.ORG | 2013-07-19 14:28:17 -0700 (Fri, 19 Jul 2013) | 1 line

 

New ISI models including Cart biases.

------------------------------------------------------------------------

r4978 | celine.ramet@LIGO.ORG | 2013-07-12 10:37:53 -0700 (Fri, 12 Jul 2013) | 1 line

 

new ham-isi master model adding the recording of the sens corr channels

------------------------------------------------------------------------

r4677 | hugo.paris@LIGO.ORG | 2013-06-10 15:20:27 -0700 (Mon, 10 Jun 2013) | 1 line

 

corrected typo on the BLRMS links of ISISTAGE/SENSCOR/, in coordinaation with LLO (CR)

------------------------------------------------------------------------

r4659 | celine.ramet@LIGO.ORG | 2013-06-07 10:33:26 -0700 (Fri, 07 Jun 2013) | 1 line

 

isihammaster mod to allow L4C or STS sensor correction-CR

------------------------------------------------------------------------

 

 

 

Check What Is Available On The Server:

 

controls@ligo-ops2:/opt/rtcds/userapps/release/isi/common/models$ svn log -l 5 ^/trunk/isi/common/models/isihammaster.mdl

------------------------------------------------------------------------

r6061 | stefan.ballmer@LIGO.ORG | 2013-10-25 12:24:57 -0700 (Fri, 25 Oct 2013) | 1 line

 

installed 32bit ODC parts for isi2stagemaster.mdl isihammaster.mdl and route signal up to top per ECR E1300740

------------------------------------------------------------------------

r5713 | jeffrey.kissel@LIGO.ORG | 2013-09-16 15:41:18 -0700 (Mon, 16 Sep 2013) | 1 line

 

committing new master models for HAM and BSC. include changes for science frame channels, ODC gain monitoring, and migraion of checker-script to the front end - not yet tested at LASTI

------------------------------------------------------------------------

r5044 | hugo.paris@LIGO.ORG | 2013-07-19 14:28:17 -0700 (Fri, 19 Jul 2013) | 1 line

 

New ISI models including Cart biases.

------------------------------------------------------------------------

r4978 | celine.ramet@LIGO.ORG | 2013-07-12 10:37:53 -0700 (Fri, 12 Jul 2013) | 1 line

 

new ham-isi master model adding the recording of the sens corr channels

------------------------------------------------------------------------

r4677 | hugo.paris@LIGO.ORG | 2013-06-10 15:20:27 -0700 (Mon, 10 Jun 2013) | 1 line

 

corrected typo on the BLRMS links of ISISTAGE/SENSCOR/, in coordinaation with LLO (CR)

------------------------------------------------------------------------

 

 

SVN UP

controls@ligo-ops2:/opt/rtcds/userapps/release/isi/common/models$ svn up isihammaster.mdl 

U    isihammaster.mdl

Updated to revision 6065

 

Note: 6065 is the "head revision" number

 

 

 

Check That The Local Copy Is Up To Date (same revision as the one on the server):

controls@ligo-ops2:/opt/rtcds/userapps/release/isi/common/models$ svn log -l 5 isihammaster.mdl

------------------------------------------------------------------------

r6061 | stefan.ballmer@LIGO.ORG | 2013-10-25 12:24:57 -0700 (Fri, 25 Oct 2013) | 1 line

 

installed 32bit ODC parts for isi2stagemaster.mdl isihammaster.mdl and route signal up to top per ECR E1300740

------------------------------------------------------------------------

r5713 | jeffrey.kissel@LIGO.ORG | 2013-09-16 15:41:18 -0700 (Mon, 16 Sep 2013) | 1 line

 

committing new master models for HAM and BSC. include changes for science frame channels, ODC gain monitoring, and migraion of checker-script to the front end - not yet tested at LASTI

------------------------------------------------------------------------

r5044 | hugo.paris@LIGO.ORG | 2013-07-19 14:28:17 -0700 (Fri, 19 Jul 2013) | 1 line

 

New ISI models including Cart biases.

------------------------------------------------------------------------

r4978 | celine.ramet@LIGO.ORG | 2013-07-12 10:37:53 -0700 (Fri, 12 Jul 2013) | 1 line

 

new ham-isi master model adding the recording of the sens corr channels

------------------------------------------------------------------------

r4677 | hugo.paris@LIGO.ORG | 2013-06-10 15:20:27 -0700 (Mon, 10 Jun 2013) | 1 line

 

corrected typo on the BLRMS links of ISISTAGE/SENSCOR/, in coordinaation with LLO (CR)

------------------------------------------------------------------------

H1 CDS
david.barker@LIGO.ORG - posted 14:36, Friday 25 October 2013 (8275)
State Word Overview MEDM Update

I brought the STATE_WORD MEDM overview screen up to date. I added the ODC models at the end stations, added the DAC CRC count on each model, moved the mid stations and DAQ units, removed the LVEA test stand units (may restore these if the LVEA test stand is to be used in the near future).

To get the new screen, please close your existing on and re-open.

Images attached to this report
H1 CDS
david.barker@LIGO.ORG - posted 14:31, Friday 25 October 2013 (8274)
CDS and DUST alarm reconfiguration

The CDS alarm handler was brought up to date with the new EX front ends. I added the EX alhConfig files to h1cds.alhConfig and added the corresponding disable records to the alarm manager IOC and MEDM. At the same time I added the PSL DIODE room DUST disable channel.

The CDS portion of the alarm manager MEDM was reordered to look like the overview MEDM.

The EX IOP models are not actually raising alarms at the moment, I need to configure the safe.snap files for the IOPs. Most probably will be next week.

H1 AOS (SEI)
jason.oberling@LIGO.ORG - posted 13:53, Friday 25 October 2013 (8273)
WBSC9 ETMx Alignment
IAS: J. Oberling
SEI: H. Radkins, J. Warner
Apollo: R. Thompson
 
We re-aligned the ETMx in Y and Z position and Yaw this morning.  I'm also going to list the current X position of the ETMx so it is logged; this large error from the design has been signed off by SYS (due to extreme difficulty in making the correction) and an equal shift will be made in ETMy to keep the arm lengths equal.

These measurements will be taken again when the HEPI actuators are reattached.

H1 ISC (SEI)
jeffrey.kissel@LIGO.ORG - posted 13:41, Friday 25 October 2013 (8271)
unintended interdependencies in sei models
I noticed (with cds/common/scripts/checkCompiledMpdel) that isihammaster.mdl is pointing to isi2stagemaster.mdl and hepitemplate.mdl:

controls@opsws4:models 0$ cat isihammaster.mdl | grep isi2stagemaster
	      SourceBlock	      "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/L4CY_BLRMS"
	      SourceBlock	      "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/L4CY_BLRMS"
	      SourceBlock	      "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/L4CY_BLRMS"
	      SourceBlock	      "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/HPI_L4C_X_BLRMS"
	      SourceBlock	      "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/L4CY_BLRMS"
	      SourceBlock	      "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/L4CZ_BLRMS"
controls@opsws4:models 0$ cat isihammaster.mdl | grep hepitemplate   
	  SourceBlock		  "hepitemplate/HEPI/STSINF"


Apparently, when the BLRMS parts were copied, the links were not broken. The same seems to be true for GNDSTSINF.

Recommended fix: make a separate library block for BLRMS. Break the link for GNDSTSINF to hepitemplate/HEPI/STSINF.

H1 SEI (SEI, SYS)
jeffrey.kissel@LIGO.ORG - posted 13:12, Friday 25 October 2013 (8270)
hepimaster.mdl, isi2stagemaster.mdl and isihammaster.mdl updated with 32bit parts
Fabrice, Stefan

Updated hepimaster.mdl, isi2stagemaster.mdl and isihammaster.mdl with the new 32-bit ODC libraries and routed the signals up to the top screen.
The are in svn as of revisions 6061 (isi's) and 6064 (hpimaster.mdl).

We modified the following 3 toplevel models, compiled and installed them:
h1hpiham4
h1isiitmy
h1isiham2
They all are running fine.

Fabrice is going to add more changes on the top level models before committing them to svn.




restart instructions
---------------------------------------

### recompile h1hpiham4
ssh h1build
cd /opt/rtcds/lho/h1/release

make h1hpiham4

### install h1hpiham4
make install-h1hpiham4

#log into the corresponding front end
ssh h1seih45
## shut down output on medm screen
starth1hpiham4 
# and hit BURT restore button
--------------------------------------------

## recompile and install h1isiitmy
ssh h1build
cd /opt/rtcds/lho/h1/release
make h1isiitmy
make install-h1isiitmy
ssh h1seib1
## shut down output on medm screen
starth1isiitmy 
# and hit BURT restore button
--------------------------------------------

## recompile and install h1isiham2
ssh h1build
cd /opt/rtcds/lho/h1/release
make h1isiham2     
make install-h1isiham2     
ssh h1seih23 
## shut down output on medm screen
starth1isiham2
# and hit BURT restore button


H1 SUS
betsy.weaver@LIGO.ORG - posted 11:45, Friday 25 October 2013 - last comment - 08:55, Tuesday 29 October 2013(8267)
SRM TFs

We looked at Arnaud's TFs taken last night on SRM and determined that there was something unhealthy in the vertical/roll, pitch directions of motion as seen by the top BOSEMs (T1, T2, T3).  Travis investigated and tweeked a few seemingly non-issues:

Slightly offcenter T2, possible loose cable connections (ha!), possibl droopy C3 cover at the top.  A quick look at DTT roll and vertical and these don't seem to have helped...  Arnaud is looking at verifying direction of excitation motion now.

Comments related to this report
betsy.weaver@LIGO.ORG - 12:47, Friday 25 October 2013 (8269)

Richard found that the binary cabling was pointing incorrectly.  He recabled according to spec and actuation has restored to the BOSEMs we couldn't see actuation on previously.  A look at a new roll DTT TF and things look healthier.

 

HOWEVER - Arnaud also pointed out that the side actuation has a sign flip somehwere.  Travis dug into documentation and found that the side BOSEM is mounted on the incorrect side of the suspension.  We'll switch it and retake the full TF set this weekend.

arnaud.pele@LIGO.ORG - 13:46, Friday 25 October 2013 (8272)

Side osem actuates in the right direction, so top mass actuation is now fully functionning. Phase 2b transfer functions will be running tonight.

betsy.weaver@LIGO.ORG - 08:55, Tuesday 29 October 2013 (8293)

In fact, the SRM is supposed to have the side BOSEM mounted opposite to most othere HSTS, with an appropriate sign flip in the side coil gain, functionality is as expected.

Displaying reports 69101-69120 of 77126.Go to page Start 3452 3453 3454 3455 3456 3457 3458 3459 3460 End