Displaying reports 71361-71380 of 83394.Go to page Start 3565 3566 3567 3568 3569 3570 3571 3572 3573 End
Reports until 14:16, Tuesday 17 June 2014
H1 ISC
keita.kawabe@LIGO.ORG - posted 14:16, Tuesday 17 June 2014 - last comment - 16:43, Wednesday 08 October 2014(12392)
HAM6 checked out for grounding

I and Dan replaced the bad UL BOSEM unit (SN of bobbin part of that assy is SN250, D0601106-C) with a good one (SN282) pulled out of spare "half-assembled" tip-tilt assy (base plate SN 034).

We also replaced UR one (SN258) with a spare (SN134) that was pulled out of the same half-assembled TT assy simply because we were not sure if the open voltage of SN258 (about 20000 counts) was too small. Later it turns out that 20k counts open voltage is not abnormal.

The newly installed units were of course assembled in the past but without fit check, and it turns out that the gap around the connector was non-existent and I had to loosen some screws and shift things around to make a good gap. I also used aluminum foil shim trick.

After this, we centered BOSEMs for all Tip-tilts to half the open voltage.

  UL LL UR LR
OM1 -16k -12k -16k -13k
OM2 -11k -11.5k -15.5k -16k
OM3 -16k -14k -16k -11.5k

WFS DC, AS_C QPD, OMCR QPDs, OMC QPDs and OMC DCPDs all responded to flash light.

Beam diverters moved back and forth.

Picomotors moved. On cable #234, the first, the second and the third channels correspond to WFSA, WFSB and AS_C picomotors. On cable #235, the first channel is the downstream 2" mirror for the QPD sled, the second the upstream 1" steering.

Checked ground loops from outside the chamber, and all cables including SUS were good except beam diverters (we know that they ground inside the chamber) and OMC QPDs (shield grounted to the DCPD signal ground) and OMC PZTs (same as OMC QPDs).

Comments related to this report
keita.kawabe@LIGO.ORG - 14:28, Tuesday 17 June 2014 (12393)

OMC PZT cable shielding also is grounded to DCPD signal ground.

Same as OMC QPDs. It's not clear from D1300376 (OMC PZT cable document) but there seems to be continuity from the shield to the mighty mouse connector shell, which is mounted on the aluminum bracket on the OMC.

LLO alog explaining these: https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=10121

keita.kawabe@LIGO.ORG - 14:48, Tuesday 17 June 2014 (12396)

As of now, ISI is locked. OMC is free.

keita.kawabe@LIGO.ORG - 14:32, Tuesday 17 June 2014 (12394)

Beam diverter cable sheild needs to be cut at the rack or at the chamber.

With the cables disconnected from the remote rack Beckhoff motor driver module, there's continuity between the cable shell and the rack. Relevant cables are cable #316 and #317.

keita.kawabe@LIGO.ORG - 14:35, Tuesday 17 June 2014 (12395)

PZT capacitance:

From the outside of the chamber, used a short DB25 and a break out board to check that PZT pins are not short circuited to stupid things. Since I was able to, I also measured the capacitance.

Pin1-14: 474nF.

Pin2-15: 428nF.

These of course include the in-vac cables and short DB25 cable I used outside.

koji.arai@LIGO.ORG - 14:56, Wednesday 18 June 2014 (12412)

Sounds the correct range for the PZTs. (spec: 470nF)

keita.kawabe@LIGO.ORG - 16:43, Wednesday 08 October 2014 (14376)

Correction: Corey found that the S/N of the pulled and newly put in BOSEMs are swapped in the above entry.

Bad BOSEM that has one PD pin grounded to the coil bobbin part is SN282.

  Pulled Newly installed
UL SN282, broken SN250
UR SN134, turns out that nothing was wrong. SN258
H1 SUS
betsy.weaver@LIGO.ORG - posted 10:41, Tuesday 17 June 2014 - last comment - 12:38, Tuesday 17 June 2014(12389)
Suspect: 2 magnets possibly broken off of the SR3 intermediate mass

This morning, Arnaud mentioned that 2 of the 14 OSEM signals on SR3 were completely open light.  To which, Travis and I leaned in and said "excuse me, what??"  Apon trending and attempting to actuat, Arnaud found no life on the suspect 2 OSEMs/magnets on the M2 (Intermediate) stage of the SR3.  This screams broken magnets to us, however we cannot inspect becuase the doors are still on the chamber.  Arnaud will append trends and details of when it happened below, but we will add to the LONG vent list to fix these in-situ.  Note, the HLTS intermediate EQ stop design is very BAD (see attached pix).  The bottom EQ stops of the intermediate mass are pretty much inaccessible - they can only be accessed via sticking your hand through the optic below.  Tools do not help.  Likely the lower EQ stops were not set close enough to the mass.  (Ignore the red circle in the first picture - it highlights a whole different problem.  The inaccessible EQ stops are in the green circle on the 2nd picture.)

Images attached to this report
Comments related to this report
arnaud.pele@LIGO.ORG - 12:38, Tuesday 17 June 2014 (12391)

On may 28th, UR and LL M2 osems signals changed from ~13000 cts (nominal value when flag is centered) to their open light values (~25000cts), see attached screenshot
Several tests were tried, and they all confirm that the magnets are probably off :

1. Sent an offset in L to the top mass of suspension to pull the masses, expecting the osem signals to decrease. UL and LR osems decreased by ~7000cts UR and LL didn't change.

2. Sent a drive sinusoidal signal at the first pitch mode frequency (0.65Hz, 100000cts) in each of the osems, expecting the test mass to respond in pitch at the same frequency.
M2 UL drive : M3 responding
M2 LL drive : M3 not responding
M2 UR drive : M3 not responding
M2 LR drive : M3 responding
 

Images attached to this comment
H1 SUS
betsy.weaver@LIGO.ORG - posted 08:46, Tuesday 17 June 2014 (12387)
ITMx BSC1 install work

ITMx Install:

Yesterday, Travis and I connected and aligned all 12 top stage BOSEMs and made a round of course alignment on both main and reaction chains of this QUAD sus.  We then attached the corner cube mount and took the optic position-to-cube measurements for IAS.  We swung the ACB back into position such that IAS can have line-of-sight to the ITMx from the x-spool, so we anticipate X,Y,Z numbers from IAS later this morning.

LHO General
corey.gray@LIGO.ORG - posted 08:40, Tuesday 17 June 2014 (12386)
Morning Installation Meeting Minutes
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:30, Tuesday 17 June 2014 (12385)
CDS model and DAQ restart report, Monday 16th June 2014

model restarts logged for Mon 16/Jun/2014
2014_06_16 14:47 h1nds1
2014_06_16 14:57 h1nds1
2014_06_16 16:25 h1fw1

All restarts were unexpected. These systems relate to the default NDS, which may not be a coincidence.

H1 ISC
keita.kawabe@LIGO.ORG - posted 17:32, Monday 16 June 2014 - last comment - 23:46, Monday 16 June 2014(12382)
Tip tilt and ground loop woes continue (Dan, Keita)

Summary:

OM2 was rebalanced, but one of the BOSEMs is bad (one of the PD pin is grounded to the tip tilt body). We will replace it with a spare tomorrow.

We found that the shielding of QPD sled picomotor cablesand WFSA DC cable were grounded to the ISI. The former was fixed by loosening the DB25 connector mating screws and pulling the DB25 back a bit. The latter was fixed by loosening an ultra-tight cable clamp at the stage zero of the ISI.

Please do never tighten the cable clamps so hard that the cable cannot move. You should be able to move the cable through the clamp by pulling gently, though the cables should stay in place by friction when left alone.

Details:

 

I pulled the OM2, rebalanced, installed again, made sure that BOSEM flags don't interfere, set the BOSEM depth, and THEN found that some of the ground loops were back, and one of them was of course OM2 itself (not the cable).

Pulled OM2 again, and it turns out that the coil with a tiny gap that was OK before was touching, causing the grounding issue. By pushing or pulling the connector using my finger, I was able to make or break the connection, and when I remove my pressure it didn't go back to the original state.

I applied aluminum foil as a shim between the coil bobbin and the connector to make the bottom gap larger, and cocked the connector more to make the side gap larger (I needed to make one of the mating screws somewhat looser than the other), so that there is a clear visible gap all around the metal shell of the connector. It was tested good on the work table, so we installed it back to the table.

When we started setting the depth of the BOSEMs, UL coil was stuck at -8000 or so counts (it was not in the morning, but Dan recalls that that coil was stuck at that value on Friday).

I pulled the coil out while keeping the electric connection intact, and as soon as the coil came out suddenly the open value was -32k counts. As soon as the coil touches the ISI surface, it went back to -8000 counts.

It turns out that one of the pins for the PD for the BOSEM is short circuited to the coil bobbin, and of course the coil bobbin is grounded to the tip-tilt frame. In the morning, for some magical reason, it should have been that the PD pin was not short circuited, or the coil is not grounded to the tip-tilt frame.

Anyway, this is clearly a bad part, and we need to replace it with a spare.

Also UR coil open voltage is somewhat small (-20000 cts), so we'll see if replacing this BOSEM changes it.

Comments related to this report
daniel.hoak@LIGO.ORG - 23:46, Monday 16 June 2014 (12384)

Attached is a picture incdicating which connection on the BOSEM is shorted to the body.  According to T060233, it's one of the pins on the photodiode (which has the round hole; the IRLED has the slit, inside the BOSEM body).  With the BOSEM removed from the TT assembly we were able to use an allen key as a flag to block the shadow sensor and see some variation in the signal.  With the BOSEM touching a conductive surface the signal is stuck at about -6800 counts.  (Thanks to Keita's careful shimming, the cable connector shield is not electrically connected to the body of the BOSEM.)

Images attached to this comment
H1 SUS
filiberto.clara@LIGO.ORG - posted 16:28, Monday 16 June 2014 (12381)
SUS Watchdog chassis installed in CER
Installed SUS Watchdog Chassis D1300642 in rack SUS-C6-U26. Unit is powered up, and the only connections made to the unit are the binary inputs/outputs.

Filiberto Clara
H1 AOS
hugh.radkins@LIGO.ORG - posted 16:15, Monday 16 June 2014 (12380)
WHAM5 ISI Generic Isolation Loop (Lvl1) only works with 100mHz Blend

Started with the 750mHz.  It would trip the Actuator with the script so went to hand method.  Going dof at a time, was able to get the RZ RX  & RY dofs on with boosts and they were pretty quiet.  Could get Z on too but it would go unstable quickly when either the X & Y dof was included.  Checked the local to cartesian matrices and they are correct.  Looked at the parameter file in case the loops were created with incorrect matrices...but I could not find that info in the parameter file so not sure if you can determine that.  I did then spot the Blend filter and it said 01_28.  So, I changed the blend to 01_28 and tried the script again but it would still trip out quickly.  Same story on the 250mHz.  However, it is stable with the 100mHz blend...weird.

Attached is a isolated/damped only comparison.  The reference traces are with the lvl1 isolation and 100mHz blends.  The current rraces only have damping engaged.  This isolation does a fair amount of good in various places especially below a few htz but it appears to have resonances and other ill effects at various places above several htz....

Images attached to this report
LHO General
thomas.vo@LIGO.ORG - posted 16:03, Monday 16 June 2014 (12379)
06/16/2014 Ops Summary

- Hugh out to HAM6

- Betsy to Beer garden then to the west bay

- Jeff out to beer garden with film crew

- Jason to ITMX alignment

- Fred and film crew in the LVEA

- Sheila and Greg into the PSL for pictures

H1 SUS
filiberto.clara@LIGO.ORG - posted 15:45, Monday 16 June 2014 (12378)
Grounding plugs added to SUS coil drivers at EY and EX
While doing the AA/AI rework last week, installed grounding plugs (per L1200193) to all SUS coil drivers at both EY and EX. The plug is attached to the DB9 connector labeled Test Input. This completes all installed electronics in CER, EX, and EY.

Filiberto Clara
LHO General
bubba.gateley@LIGO.ORG - posted 15:41, Monday 16 June 2014 (12377)
Apollo crew
5 viewports were installed on MCB 2 today. Ref. W P 4673.
H1 General
filiberto.clara@LIGO.ORG - posted 15:40, Monday 16 June 2014 (12376)
AA AI chassis rework - EX
Per bugzilla integration issue 463, looked at AA/AI chassis to verify units have the proper insulating film used to isolate the -15V regulators to the chassis metal wall. 

All AA/AI chassis at EX have been modified or verified to have the appropriate insulating film.

SUS
S1100321 S1105306 S1105295 S1103819 S1202273 S1202611 S1202819 S1202612 S1202820

SEI
S1300132 S1300135 S1300136 S1300140 S1300144 S1300611

ISC (including Whitening chassis)
S1102763 S1102781 S1102777 S1101606 S1101587 S1101631 S1101642

All electronics have been reconnected and powered up. All units were placed back in appropriate rack and slot location.

Filiberto Clara
H1 General
filiberto.clara@LIGO.ORG - posted 15:37, Monday 16 June 2014 (12375)
AA AI chassis rework - EY
Per bugzilla integration issue 463, looked at AA/AI chassis to verify units have the proper insulating film used to isolate the -15V regulators to the chassis metal wall. 

All AA/AI chassis at EY have been modified or verified to have the appropriate insulating film.

SUS
S1107601 S1105299 S1105300 S1103818 S1202280 S1103775 S1103772 S1103774 S1103773

SEI
S1103403 S1103401 S1103406 S1103409 S1103510 S1103501

ISC (including Whitening chassis)
S1102755 S1102764 S1102765 S1101600 S1101638 S1101595 S1101579

All electronics have been reconnected and powered up. All units were placed back in appropriate rack and slot location.

Filiberto Clara
H1 SUS
arnaud.pele@LIGO.ORG - posted 14:35, Monday 16 June 2014 (12374)
TMSX electronics noise

Dave reported this morning that TMSx osems readback were moving too much. Looking at a spectra from one of those osems, a 1777Hz line appears to be the main source of oscillation. This looks similar to a problem we had few months ago with one of the sat boxes of the BS (cf alog 7237). We will reboot the sat box and see if that changes it.

Images attached to this report
H1 PEM (CDS)
james.batch@LIGO.ORG - posted 11:00, Monday 16 June 2014 (12373)
Mid X weather station back online.
The weather station at Mid X has been restarted after replacing an isolator between the weather station and the comtrol serial interface box.  Wind alarms have been set to 30 and 40 MPH.

End X is online, but the anemometer is not working at this time.
H1 SEI (INS, ISC)
hugh.radkins@LIGO.ORG - posted 10:14, Monday 16 June 2014 (12372)
WHAM6 ISI is now Locked

Keita is removing a tiptilt so I locked up the ISI.  It was already out of balance and probably should have remained locked anyway.  The cables that were moved from stage1 was enough to unbalance the table.

Once Keita returns the TipTilt, SEI will need to rebalance the table.

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 10:11, Monday 16 June 2014 (12371)
CDS model and DAQ restart report, Saturday and Sunday 14th,15th June 2014

No restarts reported.

H1 TCS (TCS)
greg.grabeel@LIGO.ORG - posted 18:30, Friday 13 June 2014 - last comment - 16:45, Wednesday 18 June 2014(12365)
ITMy Ring Heater Forensic
Thanks to the efforts of SUS I was able to get in and look at the ring heaters of ITMy today. There are no apparent problems with breakage of either the glass formers or the macor retaining pieces. However, the center macor piece (D1002545) looks to have wandered off center quite significantly. I didn't have any pictures from that angle while the quad structure was still in chamber. So, unfortunately, I am unable to determine when it wandered off, but it definitely warrants looking at ITMx closely before it leaves BSC 3 if possible. 

It should be noted that this is the older style of ring heater, but the macor element standoff is the same throughout all but the most recent version.
Images attached to this report
Comments related to this report
greg.grabeel@LIGO.ORG - 09:10, Monday 16 June 2014 (12370)TCS
As requested a picture with a few labels, showing how the macor has wandered off the center point where it should be.
Images attached to this comment
greg.grabeel@LIGO.ORG - 16:45, Wednesday 18 June 2014 (12414)TCS
The old ring heaters on ITMy have been removed from the old quad structure. While I was packaging the upper and lower ring heater I noticed quite a bit of particulate coming out. Looks like glass, certainly warrants a closer inspection.
Images attached to this comment
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