Displaying reports 71701-71720 of 83316.Go to page Start 3582 3583 3584 3585 3586 3587 3588 3589 3590 End
Reports until 12:16, Monday 19 May 2014
H1 AOS (INS, SUS)
jason.oberling@LIGO.ORG - posted 12:16, Monday 19 May 2014 (11969)
SRM Surrogate Alignment Tentatively Complete
IAS: J. Oberling
SUS: B. Weaver
 
The fine pitch/yaw alignment of the SRM surrogate was completed this morning (actually, no alignment was required.  Upon setting up equipment to measure the pitch/yaw it turns out we got everything in spec during the rough alignment last Friday).  My equipment is still set up until I get word from SUS that the suspension is healthy; I will also post final alignment numbers at this point.
H1 PSL
jeffrey.bartlett@LIGO.ORG - posted 12:11, Monday 19 May 2014 (11968)
PSL Status Check
As of 12:00

PSL Status: 
SysStat: Green, except VB
Output power: 26.7w  
FRONTEND WATCH: Good
HPO WATCH: Red  

PMC:
Locked: 12min
Reflected power:   1.5w
Power Transmitted: 9.8w 
Total Power:      11.3w 

FSS:
Locked: 12min
Trans PD: 0.94v

ISS:
Diffracted power: 3.833%
Last saturation event: 12m
H1 General
jeffrey.bartlett@LIGO.ORG - posted 11:00, Monday 19 May 2014 (11966)
Morning Meeting Minutes
Jason & Betsy – SRM fine alignment at HAM5
Gerardo – Putting the OFI into storage box and fly over beam tube
Hugh – ISI balancing at HAM4
Travis – ACB balance and alignment
Richard & Filiberto – Chassis work in EE shop & cabling at HAM6
Peter & Olli – In H2-PSL working on ISS assembly
Dave – TCS Hartman table alignment
H1 SYS (SEI, SUS, SYS)
jameson.rollins@LIGO.ORG - posted 10:22, Monday 19 May 2014 - last comment - 17:26, Monday 19 May 2014(11965)
lockloss SUS and SEI watchdog trips should probably be addressed in the watchdog code

The problems we noted over the weekend with the ETM SUS (and sometimes SEI) systems tripping on lock loss (alog 11957) can maybe most accurately be characterized as a watchdog problem.  The trips are caused by large drive transients after lock loss.  It's hard to imagine that there's much we can do to prevent this from happening.  Even if the DARM (CARM, etc.) control signals could be shut off immediately, the residual impulses would still produce large impulse response in the LOCK filters in the suspensions.    We could try to shut off the drive signals in the SUS controllers, or hold the outputs at their current value, but that's a bit more difficult to implement.

In general, though, the watchdogs should probably just not be tripping on transients.  If the watchdogs were a bit smarter and only tripped on sustained saturations or oscillations, this would likely not be an issue.  I vote that we solve the problem in the watchdogs, but increasing the amount of time it takes before they trip.

Comments related to this report
arnaud.pele@LIGO.ORG - 17:26, Monday 19 May 2014 (11975)

I closely looked at one of saturday's trip on ETMX @ 04:44:40 UTC (May 18th 2014). The sequence was :

  • Large kick to UIM actuators (~2e8 cts) (RMS of osems exceeded ~10000cts)
  • ONLY UIM wd trips (the other WD were set at 80000 instead of 8000)
  • ISI ST2 trips on GS13

I will post some data tomorrow

H1 ISC (IOO)
kiwamu.izumi@LIGO.ORG - posted 09:22, Monday 19 May 2014 (11964)
IMC WFS centered

Just for a bookkeeping purpose:

I recentered the beam on the IMC WFSs on this past Saturday. I used the picomotors. Both of them had been off by 0.2-ish counts in the normalized pitch and yaw.

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:32, Monday 19 May 2014 (11963)
CDS model and DAQ restart report, Sunday 18th May 2014

No restarts reported.

H1 IOO (SYS)
jameson.rollins@LIGO.ORG - posted 19:22, Sunday 18 May 2014 (11961)
IMC guardian updates

I made a couple of improvements to the IMC guardian:

The final point was to make it so that there is no activity in the LOCKED state, so that reaching the LOCKED state means that the IMC is fully up.  In general, I think we should start making all requestable states be "idle" states in that they don't do any action other than monitoring for exit conditions.  This idea here is to make them true markers of a steady state of the system.

We end up with just two requestable states now: DOWN and LOCKED.  The DOWN state doesn't actually prevent the IMC from locking briefly, so we may want to change the DOWN state to something that actually prevents the IMC from locking.

Next, I want to make the IMC guardian the manager of the SUS_MC{1,2,3}, so IMC is actually in control of setting the MC suspensions to their ALIGNED states.  This will also allow us to achive the point above, since we can then make the DOWN state into something where the SUS are misaligned, thereby preventing the IMC from locking.

Images attached to this report
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:58, Sunday 18 May 2014 (11960)
CDS model and DAQ restart report, Friday and Saturday 16th,17th May 2014

model restarts logged for Fri 16/May/2014
2014_05_16 23:12 h1fw1

No restarts reported for Saturday.

One unexpected restart of h1fw1 over the two days.

H1 ISC
lisa.barsotti@LIGO.ORG - posted 01:18, Sunday 18 May 2014 - last comment - 01:47, Sunday 18 May 2014(11958)
3f + dual arm tonight: some progress

Kiwamu, Jamie, Lisa

We figured out why we couldn't reduce the CARM offset below 1kHz while keeping the PRMI locked on REFL 45 I&Q.

The REFL 45 demod phase was tuned without the arms present; it turns out that with the arms, even with a large CARM offset (1 kHz), the demod phase changes enough to make MICH very close to instability.

So, we just tuned the REFL 45 phase by monitored the MICH OL TF and the REFL 45 I/Q decoupling by looking at a PRCL line around 50 Hz.

Not a very advanced technique, but we could recover pretty easily a reasonable shape for the MICH loop and we could reduce the CARM offset.

Kiwamu will post some plots with the MICH OL TF; here are some numbers for the REFL 45 phase:

Without the arms: 144 dg

1 kHz --- 900 Hz CARM offset: 172 dg

800 Hz  --- 700 Hz CARM offset: 180 dg

We were happy and ready to do the transition to 3f, but another seismic event like the previous one made the lock of the Y arm more difficult. 

We are still debating if we should go home or not...

 

 

Comments related to this report
kiwamu.izumi@LIGO.ORG - 01:47, Sunday 18 May 2014 (11959)

Fig.1 MICH open loop transfer functions. The pink curve is the one after we adjusted the demod phase at a CARM offset of 1 kHz. Everything else is the ones before the adjustment. You can see that the funny bump between 20 and 50 Hz dissappered as we adjusted the demod phase.

Fig.2 PRCL open loops. The red curve is the one after the demod phase adjustment. The blue one is before the adjustment. Not a significant difference.

Fig.3 Various error signals for the length control. The references were taken when the CARM offset was at 1 kHz and the live traces are the ones with the offset at 800 Hz. REFL45I sees more noise above 40 Hz which is seemlingly from the common mode. A peak at 50 Hz is our injection in PRCL for calibrating the responses.

Images attached to this comment
H1 ISC (SYS)
jameson.rollins@LIGO.ORG - posted 00:55, Sunday 18 May 2014 (11957)
ALS_DIFF DARM lock loss kicks ETM SUS and trips watchdogs

[Jamie, Kiwamu, Lisa]

The ETM SUS are getting kicked to the point of watchdog trips when the we lose the ALS DARM lock.  The DOWN state of the ALS_DIFF guardian was shutting off the INPUT to the LSC-DARM filter bank, but not the OUTPUT, so we were suspecting that leftover filter stuff was being driven out to the suspensions.  There are also no LSC triggers associated with the ALS error signals that could shut off the DARM output after lock loss.

I modified the ALS_DIFF DOWN state to turn off the DARM output as well, in the hopes that that would reduce the problem.  We thought that that did help, but then we just got another lock loss that did trip the ETMY SUS and ISI ST2 watchdogs, so it didn't elliminate the problem entirely.

I wonder if we'll need to add some LSC triggering based on the ALS inputs, for when we're using ALS signals to feed back to the SUS.

While I was at it, I did a bunch of code cleanup in the ALS_DIFF module.  Mostly just to keep things consistent with the guardian style guide (unpublished).  I also committed the ALS_DIFF.py module to the USERAPPS svn, and added it to the GUARD_OVERVIEW medm screen.
 

H1 PEM (PEM, SEI, SUS)
lisa.barsotti@LIGO.ORG - posted 20:58, Saturday 17 May 2014 - last comment - 22:26, Saturday 17 May 2014(11955)
Polarized seismic distrubance

Kiwamu, Jamie, Lisa

Today we had the illusion that we could start locking before dinner time, but that didn't happen.

While both the X and Y arms were locked on green, something happened in the corner station (visible in the PEM CS SEIS 30-100 mHz channels, especially Z) which affected only the Y arm, while the X arm remained happily locked.

Images attached to this report
Comments related to this report
kiwamu.izumi@LIGO.ORG - 22:26, Saturday 17 May 2014 (11956)ISC

I added a very-low-frequency-boost in the BS oplev damping loop which reduces the motion between 10 mHz to 100 mHz.

When seismic was high as Lisa reported, BS also moved a lot in yaw by 1.5 urad in pk-pk. This was causing a power modulation in the ALS diff beatnote. So I added this filter to reduce the motion at very low frequencies. Also, I increased the gain for this loop from -0.03 to -0.05 as there was a servo instability at 1-ish Hz with the VLF boost engaged. When seismic is at the normal level, do not forget to disengage this VLF boost.

H1 ISC
kiwamu.izumi@LIGO.ORG - posted 04:01, Saturday 17 May 2014 - last comment - 20:49, Saturday 17 May 2014(11952)
3f + dual arm tonight: no real progress

Lisa, ChrisW, Jamie, Arnaud, Kiwamu

We locked the PRMI with the 1f signals at a CARM offset of 1-2 kHz. The goal is to hand it over to the 3f after the CARM offset passes approximately 1 kHz at which the arm cavities resonate with the 2f sidebands. However, we didn't get a real progress tonight. We will continue studying this configuration.

What we did:

Comments related to this report
lisa.barsotti@LIGO.ORG - 20:49, Saturday 17 May 2014 (11954)

"At some point, we noticed that the cavity stay locked without the slow feedback. So we stopped using the slow feedback."

There was high wind last night until around 2 am. Kiwamu's locking successes started when the wind stopped blowing. According to Robert's FOM, the wind was indeed pretty high, around 90% percentile..but still, I claim that we should be able to lock a cavity anyway.

We will try to produce meaningful plots, in the meantime here is the plot which has the times with high wind, as looking at the PEM EX SEIS BLRMS 1-3Hz.

Images attached to this comment
H1 SEI
fabrice.matichard@LIGO.ORG - posted 17:51, Friday 16 May 2014 (11950)
Stage 1 Drive to T240 RZ Decoupling

The coupling from the BSC-ISI Stage 1 Z drive to the T240 RZ signal reported a few weeks ago has been lately our first guess as for what's limiting the RZ (Yaw) isolation performance.

This week we modified our real time model to do subtraction tests. The modification has been installed on ITMY.

The first plot attached shows:

- the coupling measurement in green

- a simple fit to be used in the subtraction block, in black

- the expected residual coupling in red

 

The second plot shows the residual coupling measured after installing the correction. The subtraction results look pretty good. Unfortunately, I did not observe substantial improvement in the optical lever Yaw motion. To be further investigated...

 

 

Images attached to this report
H1 TCS (TCS)
thomas.vo@LIGO.ORG - posted 16:53, Friday 16 May 2014 (11949)
TCS Progress
G. Grabeel, D. Hosken, T. Vo

CO2X:
- Running all day today and last night, turned off at 23:25 UTC.
- Shipped out flipper mirrors and central heating masks for testing at CIT.

HWS:
- Visible laser alignment of the Y section of the HWS optics table complete up till the periscope, excluding the HWS.  
- Position sensors checked and working properly.
- X side of the table has all the optics mounted and we'll set them in place and align on Monday.

RH:
- ITMX RH is hooked up but the drive is about half as much as we request compared to ITMY.  We're investigating the possible causes now, the Beckhoff controls seem to be working alright.

Updated to latest MEDM SVN revisions to match LLOs recent changes.
H1 General
jeffrey.bartlett@LIGO.ORG - posted 16:28, Friday 16 May 2014 (11948)
PET Swipe in HAM5
Took PET swipe in HAM5 after the installation of H1-SRM and before we started the alignment. 
H1 SEI
hugh.radkins@LIGO.ORG - posted 16:28, Friday 16 May 2014 (11947)
SEI ISI Build Updates
3rd IFO unit#2 is essentially done testing.  Collecting info from minor static tests are all that remains.
Unit #3 is built up to a test state for MIT--looking at coupling from the EM actuators to the sensors.  We have a few CPSs left to connect and cable.  We should be ready to do this test by Wednesday.  Once this test is done we'll need to back track a little to build it right and float the table.  Something like another week after this special test.  Meanwhile we'll dance large plates for Unit #4 around with the Container to get unit#2 out of the Staging building early next week.
H1 SEI
jameson.rollins@LIGO.ORG - posted 09:10, Friday 16 May 2014 - last comment - 15:26, Saturday 17 May 2014(11936)
BS ISI stage 2 GS13 watchdog tripped

Came in this morning to find the BS ISI stage 2 GS13 watchdog tripped.  Unclear why.

The strange thing is that the trip appears to have occured at GPS 1084253752, which is 10:30pm last night, whereas commissioning finished up around 4:30am.  Did they just run with the BS tripped all night?

The watchdog was reset and guardian recovered everything fine.

Comments related to this report
sebastien.biscans@LIGO.ORG - 09:27, Friday 16 May 2014 (11938)

The ISI-BS is a little peculiar: we know that the Michelson feedback could send a kick to the ISI and trip ST2 watchdogs. It's very often that the commissioners work with ST2 tripped, and I wouldn't be surprised that's what happened last night.

Given that, you should double check with the crew to see if it was really the case.

jameson.rollins@LIGO.ORG - 15:26, Saturday 17 May 2014 (11953)

This was indeed the case.  The michelson lock was kicking the BS and tripping stage 2, so they just ran with it tripped.

This is obviously an untennable solution, so we need to figure out how to prevent the BS ISI from tripping during acquisition.

Displaying reports 71701-71720 of 83316.Go to page Start 3582 3583 3584 3585 3586 3587 3588 3589 3590 End