Displaying reports 71581-71600 of 83224.Go to page Start 3576 3577 3578 3579 3580 3581 3582 3583 3584 End
Reports until 15:51, Tuesday 20 May 2014
H1 SEI (SEI)
justin.bergman@LIGO.ORG - posted 15:51, Tuesday 20 May 2014 (11995)
OPS: reset of HEPI L4C Accumulated WD Counters Tuesday 20nd May 2014

HAM 4

LHO General
justin.bergman@LIGO.ORG - posted 15:43, Tuesday 20 May 2014 (11981)
ops

0905 - Richard working on ETM ESD in control room.

915 - Gerardo + John to MY to relieve pressure on valved out vacuum gauge (currently presenting 6e-5 torr)

925 - Jeff & Andres - Live at the H2 Enclosure one night only for OFI move to HAM5 Area and OFI Install.

945 - Travis & Margot & Fil - ACB staging area in LVEA (test stands)

1045 -  Praxair delivery

1102 - KingSoft onsite

1130 - Filiberto climbing on top of HAM 1 & 2

1330 - OFI install halted while Arnaud runs some TFs on HAM5

H1 SUS
betsy.weaver@LIGO.ORG - posted 15:27, Tuesday 20 May 2014 (11994)
purge air back up HAM4-6

This morning (9:20am-ish) I turned the purge air back up that is plumbed into the East side of HAM4.  It had been reportedly turned down yesterday.  Soft covers which were weakly billowing are back to full billow.

H1 AOS (INS, SUS)
jason.oberling@LIGO.ORG - posted 12:54, Tuesday 20 May 2014 (11992)
SRM Surrogate Final Alignment Numbers
Here are the final alignment numbers for the SRM surrogate optic.
H1 SUS (SEI, SUS)
hugo.paris@LIGO.ORG - posted 12:20, Tuesday 20 May 2014 (11990)
SR2 WD re-connected to ISI WD

I re-ennabled the path from SR2 WD to HAM4-ISI WD in h1sussr2.mdl, then re-compiled and restarted it.

The new model is commited under the svn -r8034

Work was perfomed under WP # 4639 which is now closed.

H1 SUS
betsy.weaver@LIGO.ORG - posted 12:10, Tuesday 20 May 2014 - last comment - 12:21, Tuesday 20 May 2014(11987)
SRM OSEMs aligned despite poorly designed brackets

This morning, I aligned the 3 stages of OSEMS (14 in total).  This involved some clean filing of one fo the middle stage brackets.  A month ago, we noticed that this bracket held the AOSEM already at an extreme in height range, however after beating the streets to see what could be done (via SUS engineering and SUS LLO), we decided to leave it and hope we didn't need more range.  The recent SRM mass alignment has sent a small differential pitch up the chain causing this AOSEM to now need more height range.  Dam*.  The bracket itself has slots for additional height adjustment, however the bracket then runs into the side of the AOSEM itself (hence the poor design statement above).  Since we can't do much at this point to fix the range, I disassembled the bracket, removed the AOSEM and filed the bracket down where it hits the AOSEM.  I used a Class B file.  There is another AOSEM hugging the edge of the mechanical range, but I'm leaving it for now.

 

With improved mechanical range on this one AOSEM, I was able to align it and the rest of the OSEMs.  I've run quick TFs in V, L, and R - all look good so the chamber is ready for OFI installation (and for Jason to post final alignment numbers of SRM).

Comments related to this report
betsy.weaver@LIGO.ORG - 12:15, Tuesday 20 May 2014 (11988)

This is how the magnet looked in the UR M2 AOSEM before bracket "attitude adjustment".

Images attached to this comment
betsy.weaver@LIGO.ORG - 12:19, Tuesday 20 May 2014 (11989)

This is the bracket-AOSEM mechanical intereference that didn't work today.  (Note, we've reported that on many of our HSTS suspensions at LHO these brackets are at the end of their range, it just bit us this time.  I do not know why they are all high at this stage, but the suspension pendulum modes match the model so the pendulum lengths are correct.  Our last round of diagnosis on this many months ago was hand washed off that the LHO suspension structures were possibly from a different batch than the LLO ones and therefore there is a mechanical difference in how these AOSEMs are mounted.)

Images attached to this comment
betsy.weaver@LIGO.ORG - 12:21, Tuesday 20 May 2014 (11991)

And this is the bracket with my hand-crafted AOSEM relief shape which shoulda been in the bracket in the first place.

Images attached to this comment
H1 ISC
daniel.sigg@LIGO.ORG - posted 11:17, Tuesday 20 May 2014 (11986)
Increase of the 45MHz modulation depth

Added a ZHL-1A RF amplifier to the 45MHz RF signal which goes to the EOM. The RF power measured at the patch panel in the LVEA is now 25.3dBm from 12.7dBm. There is a 6dB attenuator in front of the RF amplifier which can be replaced with a 12dB one, if the gain is too high. The modulation depth was measured in alog 9395. There seems to be a 2dB loss between the LVEA patch panel and the EOM. If correct, the modulation depth is now 0.3 and the 3f-signal strength about 70 times higher. With a little bit of cable and barrel magic the phase was restored to within 1 degree.

H1 SUS
jameson.rollins@LIGO.ORG - posted 10:53, Tuesday 20 May 2014 - last comment - 18:26, Tuesday 20 May 2014(11982)
changes to SUS guardian

Arnaud and I have made some changes to the SUS guardian.  We broke up the graph such that the requestable states are now idle states that don't actually change the state of the suspension:

The dark blue states, which are the requestable states, now only check the alignment and watchdog status.  The reason for this change is so that guardian being in e.g. the ALIGNED state actually indicates that suspension is fully aligned.  Previously guardian would enter the ALIGNED state, even before the offsets had fully wrapped to their alignment values.  Other guardian nodes that might be watching the SUS guardians for optic alignment would therefore be misled.  This just makes the state more explict.

I also removed the goto flag from the RESET (was SAFE) state due to a bug I discovered in guardian.  The bug is that if there is a goto on the graph, then the INIT state will not be executed.  This is something I need to fix in guardian.  In the mean time, I just made all the desired transitions explicit.

Images attached to this report
Non-image files attached to this report
Comments related to this report
jameson.rollins@LIGO.ORG - 16:24, Tuesday 20 May 2014 (11996)

I wanted to mention a couple more changes that Arnaud and I made to the main SUS guardian module:

  • Added some decorator objects for wrapping functions with common checker code.  In this case we added "watchdog_check" and "alignment_check" GuardStateDecorators.  These are now used instead of explicitly making those checks in the body of the state methods.  This makes the primary logic of the methods clearer.
  • We made "state generator functions" for states having to do with optic alignment.  These functions spit out "ALIGNING" and "ALIGNED" states for various alignment settings.  We now use these functions for creating the ALIGNING, ALIGNED, and MISALIGNING, MISALIGNED states.
  • Using the above we created a SUS_TMS.py module specifically for the somewhat odd TMS suspensions that have additional alignment states: ALIGN*_TO_PD1 and ALIGN_TO_PD4.  SUS_TMS.py inherits everything from SUS.py, creates the additional alignment states, and adds
     new edges for getting to/from those states to the reset of the graph:

Arnaud will write another follow-up comment once these changes are all committed.

Images attached to this comment
Non-image files attached to this comment
arnaud.pele@LIGO.ORG - 18:26, Tuesday 20 May 2014 (11999)

The changes were commited under the svn. Details can be found under the OpsManual

H1 ISC
corey.gray@LIGO.ORG - posted 10:42, Tuesday 20 May 2014 (11985)
Replaced Cable For ISCT1 Lights

Thought the issue was a bad switch, but it was actually one of the cables.  I swapped this cable out (which wasn't easy since it was hard to see where the cable connector needed to go [& these connectors suck!]). 

LHO General (CDS, PEM)
patrick.thomas@LIGO.ORG - posted 10:27, Tuesday 20 May 2014 (11984)
dust monitor code updated to 1.3.0
This completes WP 4633.

This was done to communicate with the MetOne model 6000 installed in the H1 PSL diode room.

The h0dustdr, h0dustex, h0dustey, h0dustlab, h0dustlvea, h0dustmx and h0dustmy target directories in /ligo/lho/h0/target were copied to /ligo/lho/h0/target_archive and updated. The h0dustex, h0dustey, h0dustlvea and h0dustlab IOCs were restarted and burtrestored to the snapshot files in /ligo/cds/lho/h0/burt/2014/05/19/08:00.

The h0dustdr IOC was started. The settings were changed to:
Sample Time: 20 seconds
Hold Time: 300 seconds
0.3 micron minor alarm: 100
0.3 micron major alarm: 200
0.5 micron minor alarm: 100
0.5 micron major alarm: 200
LHO VE
john.worden@LIGO.ORG - posted 10:20, Tuesday 20 May 2014 (11983)
MID Y vacuum PT246

Gerardo and I pumped out the dead space around PT246 and closed the valves to their prior state.

LHO General
justin.bergman@LIGO.ORG - posted 09:18, Tuesday 20 May 2014 (11980)
notes from tuesday morning meeting

SRM looking good; Betsy plans to do final check and hand off to OFI today

Apollo will be craning OFI over beam tube

Gerardo s. closing GV5/GV7 in anticipation of craning

HAM4 ISI floating, HEPI locked

McCarthy and Fil pulling cables at HAM5/6

Dan Hoak/Corey working on SLED buildup for HAM6

TCS calibrating CO2Y, troubleshooting interlock system CO2X

laser hazard expected ~1400

Corey swapping light in ISCT1 and manhandling things with Bubba in the squeezer bay

control room tour expected 1230-1300

King Soft expected

 

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:51, Tuesday 20 May 2014 (11979)
CDS model and DAQ restart report, Monday 19th May 2014

No restarts reported.

H1 ISC
lisa.barsotti@LIGO.ORG - posted 01:16, Tuesday 20 May 2014 (11978)
3f + dual arm: understanding our pain

Kiwamu, Stefan, Lisa

After talking with our LLO locking friends, spending some more time trying to further reduce the CARM offset, and thanks to the fact that tonight everything else was working fine, we think we know why our CARM offset reduction is so painful.

At LLO, the transition to 3f signals can be done with a very large offset (~ 3kHz), and once the transition to 3f signals is done, there is no particular issue in reducing the CARM offset down; no adjustments are done in the DRMI control.

Here, first of all we can transition to 3f signals for PRMI only after having passed the 18 MHz resonance in the arms (~970 Hz). This implies using the REFL 45 I&Q signal down to 700-800 Hz, which can be done only by tuning the demod phase on-the-fly .

Second, once on 3f, without constantly tuning the MICH loop (gain, offset, demod phase), we can't keep the PRMI locked while reducing the CARM offset.

We realized that the problem is that here we are using REFL 27 Q for controlling MICH, instead of REFL 135 Q. This is bad because REFL 27 Q is much more sensitive to the CARM offset, and offset and gain changes for this signal are indeed predicted by Kiwamu and Anamaria's simulation (though we don't have on hand plots for the exact CARM offsets we are currently at; Kiwamu is in the process of producing more plots).

The reason why historically REFL 135 Q was not used here is that there was essentially no signal. By comparing the LLO parameters with the ones we are currently using, it looks like we should increase the modulation index by at least a factor 2 and increase the light on the BBPD.

On the other hand, once we realized what was going on, we could reduce the CARM offset down to 250 Hz, by keeping the MICH loop happy monitoring offset, gain, and demod phase, and adjust all these parameters by hand. We could probably keep going, but there is no much point in doing that if we believe that we are just making our life harder by using a hostile signal.

Here is the roadmap to reach 250 Hz:


CARM OFFSET / MICH OFFSET
700 Hz / +200 cts
600 Hz / +400 cts
550 Hz / +800 cts
400 Hz / +900 cts
350 Hz / +900 cts
250 Hz / +1300 cts (PRCL offset -1000 cts)
MICH GAIN = 2
PRCL GAIN = 1.5


Other changes we did tonight:
    1.    Stefan relaigned the full IFO (X arm green, X arm red, TMSY single shot to beat note, Y arm green, PRMI)
    2.    We added a notch in the PRCL loop for the 70 Hz periscope resonance
    3.    We realized that theTMSY YAW damping loop has been off since May 15.. we re-closed the damping..
    4.    We modified the ALS slow path to include a 40 dB 5 second ramp for smooth engaging
    5.    We re-commissioned the Y arm ITM dither alingment loops, 1 dof only, in PITCH and YAW (the PZT loops are broken for both arms since the WFS software upgrade)

H1 PEM
kiwamu.izumi@LIGO.ORG - posted 18:48, Monday 19 May 2014 (11977)
ISS reference offset readjusted

ISS was in a state where he tries to engage the loop but keeps failing. So I re-adjusted the reference DC signal to -1.631. It fixed the issue. The diffracted power is now at 8-ish percent. Good.

Hope this will help our locking activity tonight.

H1 SEI (SUS)
arnaud.pele@LIGO.ORG - posted 14:25, Monday 19 May 2014 - last comment - 23:48, Tuesday 20 May 2014(11951)
Oplevs on friday windy night

On friday night, the wind was high(~25mph), and the arm was hard to lock. Although the angular motion of the test masses was not particularly different than on a quiet night. First attachement shows the oplev spectra from friday night, when the wind was ~25mph. second attachement shows spectra from yesterday night with a 5mph wind.

To note :

Non-image files attached to this report
Comments related to this report
lisa.barsotti@LIGO.ORG - 18:02, Monday 19 May 2014 (11976)

We tracked down the problems  we had in the past windy nights to be related with the   ALS tidal tuning , but it is still good to make these plots with the OpLEv signals.

However, I think your plots didn't turn out the way you wanted to. There is only YAW in the second attachment.

Also, it would be easier to make a comparison if you put windy/quiet  curves for each DOF in the same plot. Thanks!

arnaud.pele@LIGO.ORG - 23:48, Tuesday 20 May 2014 (12000)

thanks for noticing! 

Attached are some other plots : 

1. wind at corner and endy stations between may 17th/may 20th. High winds references are marked in orange, low winds is in green

2. Spectra comparison of ground sensors (HEPI STS) at end and corner stations with different winds. Blue and pink curves are during high winds (blue = may 17th, pink = may 18th). Red is during low winds (may 19th). From top to bottom rows : ETMX ETMY and ITMY. From left to right : X Y Z degrees of freedom. 

3. Spectra comparison of oplevs during high winds (may 18th blue curve) and low winds (may 19th red curve) for ETMx ETMy and ITMy top to bottom. Left column is pitch, right column is yaw.

Images attached to this comment
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

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