Displaying reports 48961-48980 of 87784.Go to page Start 2445 2446 2447 2448 2449 2450 2451 2452 2453 End
Reports until 13:49, Tuesday 02 January 2018
H1 SUS (SUS)
marc.pirello@LIGO.ORG - posted 13:49, Tuesday 02 January 2018 - last comment - 13:01, Thursday 04 January 2018(39946)
Triple Top Coil Driver Repaired & Replaced - SUS-C4 Rack

R. McCarthy, M. Pirello

We replaced the spare (S1001082) Triple Top Coil Driver with the repaired original (S1100195).  The original had a bad relay and was swapped back in December with the spare.  The unit was repaired, tested, and replaced into its original configuration. 

Alog of events leading up to this: 39877

Comments related to this report
jeffrey.kissel@LIGO.ORG - 13:01, Thursday 04 January 2018 (39990)
Link 

This is PR3's top mass (T3 LF RT SD) coil driver. It actually resolves the issue of PR3 (LHO aLOG 39540, LHO aLOG 39878, FRS Ticket 9497) -- not PR2 (the aLOG linked above).
H1 CDS
david.barker@LIGO.ORG - posted 13:37, Tuesday 02 January 2018 (39945)
Beckhoff slow controls IOCs at end stations restarted, fixed EDCU and autoburt problems

Daniel, Dave:

Daniel restarted the EPICS IOCs for h1ecat[x1,y1]. This fixed the DAQ EDCU and the hourly autoburt connection issues.

H1 CDS (ISC)
david.barker@LIGO.ORG - posted 13:35, Tuesday 02 January 2018 (39944)
new models for lsc, omc and sqz

Daniel, Dave:

new models for h1lsc, h1omc and h1sqz were installed. No DAQ restart was needed.

2018_01_02 13:31 h1lsc
2018_01_02 13:31 h1omc
2018_01_02 13:31 h1sqz

H1 IOO (IOO, VE)
cheryl.vorvick@LIGO.ORG - posted 12:16, Tuesday 02 January 2018 (39943)
HAM2 viewport covers

Pictures of HAM2 West and East doors showing all viewports have Lexan covers.

Images attached to this report
H1 PSL
jeffrey.bartlett@LIGO.ORG - posted 10:15, Tuesday 02 January 2018 (39942)
Weekly PSL Status (FAMIS #7471) 
   No PSL stats this week as PSL is still down for the holiday break.
H1 SQZ
sheila.dwyer@LIGO.ORG - posted 10:03, Tuesday 02 January 2018 - last comment - 11:20, Tuesday 09 January 2018(39897)
Squeezer Faraday TFP extinction ratios

The afternoon of December 22nd I went back into the optics lab and made a few measurements to try to understand why our Faraday isolation was only 20dB(see alog 39861).  It turned out that one of the TFPs had an extinction ratio that didn't meet the spec, and by switching the positions of the TFPs I was able to measure an isolation of -28dB. 

Thin Film Polarizer extinction ratio:

To measure the extinction ratio of each of the TFPs I used a set up very similar to the image in 39861, with the rotator removed (PD monitoring input power in position A, PD monitoring TFP transmission in position C which is after the Faraday path, used chopper to measure transfer function between PDs).  

After the fiber collimator, there was already in place a PBS mounted to clean up the input polarization by reflecting horizontally polarized light.  I also used whichever TFP I wasn't measuring to further clean up the polarization.  I rotated the half wave plate to measure the maximum and minimum power transmitted by the second TFP to get its extinction ratio.  For the TFP mounted with the backplate labeled SN9, I got a ratio of 2220:1 (coated side facing down in the mount, so that incident beam hit uncoated side first), for the one mounted on the backplate SN08, I got 336:1 with the coated side down and 577:1 with the coated side up (so that the incident beam first hits the coated side).  The spec for these TFPs is greater than 1000:1 (spec here)

Better Faraday Performance

In the original set up, SN08 was the first polarizer in the Faraday (the one closer to the OPO), and both TFPs were mounted coated side down.  Scattered light from the interferometer will be mostly in the polarization to be rejected by the TFP closer to the OPO, so swapped the two positions.  Now SN09 (2220:1) is mounted coated side down closer to the OPO, and SN08 is mounted coated side down further from the OPO.  

With this arrangement I repeated the measurements of isolation, transmission, and backscatter (I also increased the laser power compared to 39861).  For transmission measurements I got 95.6% and 97.6%, for isolation I got -27.9 dB and -27.8dB (0.16%), and for backscatter I got -40dB and -41dB.  

Comments related to this report
sheila.dwyer@LIGO.ORG - 11:20, Tuesday 09 January 2018 (40053)
Link

Sheila, Nutsinee, TJ

We made a couple of measurements to try to measure the Faraday rotation angle, but our measurements don't provide any better information than the constraint placed on the error by the isolation measurement.

  • The extinction ratio of the thin film polarizer that rejects the return beam is 1:2200, which places an upper limit of 33dB on the possible isolation.
  • If the half wave plate is set to maximize transmission, the polarization of the return beam before this TFP is going to be 90+2delta, where delta is the difference between the Faraday rotation angle and 45 degrees.  This will allow a fraction of sin^2(2delta) of the return beam to pass the first polarizer.  
  • We measured a return beam with 0.16% of the return beam transmitted through the Faraday.  If  0.04% is from the TFP transmitting the wrong polarization and the remained is from an error in the rotator, the rotator error is 0.98 degrees.  

We tried a few methods of measuring this, including setting the half wave plate to maximize transmission with the rotator both in place and removed and comparing the angles (47+/-3 degrees). We also used a polarizer in a rotation stage mounted after the Faraday and setting its angle to maximize transmission with vertically polarized light (with HWP and TFP after rotator left in place) and with the light directly out of the rotator.  This method gave us fairly good accuracy (about 1 degree) but we found that repeated measurements varied by up to 5 degrees, so there must be something mechanically unreliable about the rotation stage we were using. 

H1 PSL
jeffrey.bartlett@LIGO.ORG - posted 10:01, Tuesday 02 January 2018 (39941)
Monthly PSL Chiller Filter Check (FAMIS #8304) 
   Monthly chiller filter check shows all OK. The filers are clean and clear. 

   I added 200ml water to Crystal chiller, and 100ml to Diode chiller. Diode chiller was not low on water just added what was left over in the measuring cup from the Crystal chiller top off. Closing FAMIS #8304.
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 09:36, Tuesday 02 January 2018 (39940)
fixed h1nds1 access to frame files

After configuring h1nds1 to once again use framed data from h1ldasgw1 before the break, I forgot to fix the /frames symbolic link. I have corrected this and framed data (full and second trends) should be available. h1nds0 was unaffected.

LHO VE
kyle.ryan@LIGO.ORG - posted 15:09, Saturday 30 December 2017 - last comment - 17:05, Saturday 30 December 2017(39938)
1505 hrs. local -> Kyle on site checking misc. vacuum pumps etc.. 
I'll go ahead and do an impromptu site inspection while I'm here.  I expect to be here between 60- 90 minutes.

I will make a comment to this log entry when I leave
Comments related to this report
kyle.ryan@LIGO.ORG - 17:05, Saturday 30 December 2017 (39939)
Link 


Vacuum pumps and purge air are all normal.  

local gauge indications Vertex MTP (7.7 x 10-7 torr, 1.0 x 10-2 torr), XBM MTP (8.8 x 10-7 torr, 6.9 x 10-3 torr) and YBM MTP (1.1 x 10-6 torr, 8.5 x 10-3 torr)  

SITE INSPECTION:  

1)  JOY fan (HVAC) at X-mid is quite whiney/screatchy and noticeablly noiser than the rest of the fans on site -> I was unable to open the door to inspect as the internals of the door handle seem broken.  
2)  Filler cap on main chiller (ante room?) was not in place, i.e. just dangling. -> I left as found.  
3)  Weld shop door was found to be unlocked -> I locked it.  
4)  VPW above-ground waste water tank must be full as the "RED" lamp is illuminated.  

1705 hrs. local -> Kyle leaving site now, no one else here at this time.
H1 CDS
david.barker@LIGO.ORG - posted 12:29, Saturday 30 December 2017 - last comment - 13:11, Saturday 30 December 2017(39935)
CDS web access problems and general CDS status

Starting around 6pm Friday 29th PST we are seeing auth problems when accessing the internal CDS web pages using the standard LIGO authentication option. The work around is: when you get the web page with the LIGO logos, if you select the LHO Backup option you should be able to view the web pages.

Both Beckhoff end station slow controls systems are having problems. h1ecaty1 continues to run but not allow connections to the DAQ-EDCU nor the hourly autoburt. h1ecatx1 froze up on Christmas Eve (23:37 PST). Both require IOC restarts.

No other problems have been found.

Comments related to this report
david.barker@LIGO.ORG - 13:05, Saturday 30 December 2017 (39936)
Link

In other words, select the middle option.

Images attached to this comment
david.barker@LIGO.ORG - 13:11, Saturday 30 December 2017 (39937)
Link

If the LOGO for LHO:Backup is not presented, press the "Allow me to pick from a list" button to make your selection.

Images attached to this comment
LHO General
bubba.gateley@LIGO.ORG - posted 10:18, Friday 29 December 2017 (39934)
Site Inspection Completed 
The site is secure. The entire site is covered in ice and showing no signs of melting as of this moment. Let's hope the weather man is correct about the warmer temps tomorrow. All buildings checked.
LHO VE
chandra.romel@LIGO.ORG - posted 17:01, Thursday 28 December 2017 (39931)
Day's summary

IP 1,2,3 are being pumped via aux carts (valved out now). IP4 valve dead space was pumped out with loaner "cube" cart. GV5 annulus is set up to pump next week.

HAM 1 is on turbo powered through safety GFCI in case of a power failure.

All three turbos are valved into main volume and backed by local scrolls. QDP80s are OFF; water valved out.

Attempted to start leak checking but leak detector was not budging below 1.1e-8 Torr-L/s background. Postponing till next week.

Mark & Tyler worked on TMDS tables.

Dick G. was onsite for a while in the EE lab.

John Deer tech was on site for a while working on big green machine. 

 

Images attached to this report
LHO FMCS
chandra.romel@LIGO.ORG - posted 10:21, Thursday 28 December 2017 - last comment - 06:23, Friday 29 December 2017(39929)
Site check

No issues to report.

Comments related to this report
chandra.romel@LIGO.ORG - 10:31, Thursday 28 December 2017 (39930)
Link

Except that the janitor closet next to unisex bathroom in OSB has a slow leak in faucet.

bubba.gateley@LIGO.ORG - 05:49, Friday 29 December 2017 (39932)
Link 

The drip in the closet is condensate, not a faucet leaking.
chandra.romel@LIGO.ORG - 06:23, Friday 29 December 2017 (39933)
Link

Water drips from hose connected to faucet.

LHO VE
chandra.romel@LIGO.ORG - posted 08:11, Thursday 28 December 2017 (39928)
Pump down curve

Corner pressure is 1e-5 Torr this morning with two turbos valved in (pressures at turbos:  3.8e-6 & 2.8e-6 Torr). XBM turbo is humming along at 4.9e-9 Torr; will valve in after leak checking today.

Images attached to this report
Displaying reports 48961-48980 of 87784.Go to page Start 2445 2446 2447 2448 2449 2450 2451 2452 2453 End