The WHAM6 "Fast Shutter" system and OMC were repaired and replaced, respectively, during the recent vent.  The logic for the fast shutter has been augmented,  reviewed, and tested (see recent alogs for test results).  A TRB review of the OMC-shutter incident took place this morning and their recommendation was to return to normal operations.  The new fast shutter monitoring and control software (ECR E1600246) should now be in place and in routine use. Commissioining may resume at the 50W input power level of interferometer operation.

This relieves LHO alog #29010, "Input power to be held to be < 25 W until technical review of fast shutter
Notice from LIGO Systems".
 

This morning I installed the Young Model 81000 Ultrasonic Anemometer next to the wind fence at End-X. It's being powered by a sand alone 18VDC supply. All connections are being routed through two SOLA STC-DRS-038 Isolated Loop Circuit Protectors located in the rear of the electronics rack  in the VEA. There are 3 BNC pigtails awaiting connection through the PEM patch panel. Unfortunately, I didn't take a picture of the actual anemometer.

WP 6069

The copying of raw minuted trend files from h1tw1 is complete and the copied files have been verified.  The nds1 service on h1nds1 has been restarted with a new configuration to read the copied files from their new location.

[Stefan, Koji]

Quick Summary

Shutter timing test has been performed for the OMC PZT shutter and the fast mechanical shutter. Everything seems reasonable.

- The trigger logic fires at the PD input of +2V.

- The trigger logic reacts at 1.5us since the PD input thresholding.

- The PZT shutter detunes the OMC cavity at 4.8us.

- The fast mechanical shutter start blocking the beam at 1.7ms, reaches half blocking at 1.85ms, complete block at 2.0ms.

More about the test comes later.

HEPI BS Tripped few minutes before ITMX ISI.  This is the only HEPI that tripped in the neighborhood of the large quake.

ITMY ISI tripped--timing (H1:ISI-ITMY_ST2_WD_MON_GPS_TIME) indicates stage2 tripped on ACTuators 1 second before Stage1 on T240s but looking at the plots, the Actuators have only registered a few counts, nothing near saturation/trip level.  But the T240s hit their rail almost instantly.  It seems the Stage2 Last Trip (H1:ISI-ITMY_ST2_WD_MON_FIRSTTRIG_LATCH) should be indicating ST1WD rather than Actuator. On ETMY, the Trip Time is the same for the two stages and Stage2 notes it is an actuator trip but again, there are only a few counts on the MASTER DRIVE; seems this too should have been a ST1WD trip[ indication trip on Stage2--I'll look into the logic.

On the BS ISI, the Stage1 and Stage2 trip times are the same, and the Last Trip for Stage2 indicates ST1WD.  The Stage2 sensors are very rung up after the trip time but not before unlike the T240s which are ramping to to the rail a few seconds before trip.  ETMX shows this same logical pattern in the trip sequence indicators.

On the ITMX ISI, Stage1 Tripped 20 minutes before the last Stage2 trip. This indicates the Stage1 did not trip at the last Stage2 trip.

No HAM ISI Tripped on this EQ.

Bottom line: the logical output of the WDs are not consistent from this common model code--needs investigating. Maybe I should open an FRS...

Attachment 1) Trip plots showing Stage2 trip time 1 second before the stage1 trip where the stage2 actuators do not go anywhere near saturation levels.

Attachment 2) Dataviewer plot showing the EQ on the CS ground STS and the platform trip times indicated.

In an effort to eliminate the need to connect and disconnect shutter cables during vent we have moved the shutter logic controler to the rack from the table.  Also replaced the BNC cables with Yellow BNC cables so they can be easily identified.
See attachment.

Krishna,

Jenna and I had noticed that L4C 7 didn't appear to be working. L4C is close to the c-BRS, so it would have been good for comparison. In order to test if it was the instrument or the electronics, I temporarily swapped the cables with those of L4C 8 going in to the SUS rack at the LVEA. Now L4C "7" appears to be working and L4C "8" is not, indicating that the problem must be on the instrument side (or the pre-amp, I guess?). I'll swap it back in the afternoon.

  Posted below is a 45 day trend of the TCS laser power compared to operating temperature. There is a drop in power and temperature on 07/19/16 (aLOG #28506). During the HAM6 vent the RF driver was replaced (aLOG 28837) but was never tested due to lack of a beam. After the vent TCS-Y came back at ~16W with a temp of 22.   

Dear Colleagues,

As of now, LLO is closed until further notice due to widespread flooding in the area that prevents access, including emergency access.  I expect we will be able to reopen on Monday.

Any personnel or visitors on site now should immediately leave, taking US-190.  Explicit permission from either myself or Richard Oram is now required to be on site.

More details will follow, but I did not want this message delayed.  As always, liaisons should be in touch with your visitors to convey this message.

Joe

Joseph A. Giaime, Observatory Head, LIGO Livingston (Caltech); Professor of Physics & Astronomy (LSU).

phone at LIGO: +1 225 686-3169.

SEI: All back to normal after vent
SUS: All Ok
CDS: Looking into several read-back issues. Will need to do a restart of NDS1 this morning.
PSL: OK. Looking into the low power from the TCS-Y laser.
VAC: No report
FMC: No report

Relocking and commissioning work today.

I have taken camera images of the OMC R and ASAIR beam. This was primarily to compare the beam quality before and after the OMC swap. However, I did not find any obvious or significant change in the beam shapes. See the attached and compare them to the ones in 28718. Also the data is attached as well.

Stefan and Sheila working on shutter control logic. I helped resolve problems with h1ecatc1. Had to restart EPICS IOC and copy updated PLC2 to target.

23:32 UTC Gerardo to HAM6 area to check on vacuum equipment
23:39 UTC Gerardo back
03:05 UTC Joe to Y2-5 to watch meteor shower with telescope
04:30 UTC Stefan and Sheila done working on shutter control logic. Kiwamu starting work.
06:17 UTC Kiwamu to end X to investigate green laser electronics
07:00 UTC Kiwamu back

I was able to get the Y arm green power to around 1 with LOCKED_NO_SLOW_NO_WFS, but if I put it on INITIAL_ALIGNMENT it would start to be driven away. Kiwamu was investigating the X arm.

After CO2Y was powered on today, we noticed that the laser power was as low as 16 W which should be nominally 60-ish W. See the attached. This is the one with the RF driver recently swapped (28837). Needs more investigation.

J. Kissel

I took an opportunity between shutter testing and beckhoff problems to gather the final at-vacuum measurements of the HAM6 SUS. I'll process the data in complete detail tomorrow (I attach a screenshot of an example DOF from the OMC), but the message is that the TFs look just as good as they did before the vent: free, clear of rubbing, and all resonances are at the same frequency with roughly the same Q. 

Excellent!

Watch this space for full analysis and comparison with previous results.

/ligo/svncommon/SusSVN/sus/trunk/OMCS/H1/OMC/SAGM1/Data/
2016-08-11_2305_H1SUSOMC_M1_WhiteNoise_L_0p02to50Hz.xml
2016-08-11_2305_H1SUSOMC_M1_WhiteNoise_P_0p02to50Hz.xml
2016-08-11_2305_H1SUSOMC_M1_WhiteNoise_R_0p02to50Hz.xml
2016-08-11_2305_H1SUSOMC_M1_WhiteNoise_T_0p02to50Hz.xml
2016-08-11_2305_H1SUSOMC_M1_WhiteNoise_V_0p02to50Hz.xml
2016-08-11_2305_H1SUSOMC_M1_WhiteNoise_Y_0p02to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM1/SAGM1/Data/
2016-08-11_2249_H1SUSOM1_M1_WhiteNoise_L_0p03to50Hz.xml
2016-08-11_2249_H1SUSOM1_M1_WhiteNoise_P_0p03to50Hz.xml
2016-08-11_2249_H1SUSOM1_M1_WhiteNoise_Y_0p03to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM2/SAGM1/Data/
2016-08-11_2151_H1SUSOM2_M1_WhiteNoise_L_0p03to50Hz.xml
2016-08-11_2151_H1SUSOM2_M1_WhiteNoise_P_0p03to50Hz.xml
2016-08-11_2151_H1SUSOM2_M1_WhiteNoise_Y_0p03to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM3/SAGM1/Data/
2016-08-11_2257_H1SUSOM3_M1_WhiteNoise_L_0p03to50Hz.xml
2016-08-11_2257_H1SUSOM3_M1_WhiteNoise_P_0p03to50Hz.xml
2016-08-11_2257_H1SUSOM3_M1_WhiteNoise_Y_0p03to50Hz.xml

Krishna

Here are the recorded c-BRS associated channels and their calibrations (I think it is accurate to <20%):

1. H1:NGN-CS_CBRS_RY_PZT1_CTRL_IN1_DQ  :   PhotoDiode 1 output  :  1.6e-10 rad/count

2. H1:NGN-CS_CBRS_RY_PZT1_MASTER_OUT_DQ : PZT1 output  :  2.8e-10 rad/count

3. H1:NGN-CS_CBRS_RY_PZT2_CTRL_IN1_DQ  :   PhotoDiode 2 output  :  1.23e-10 rad/count

4. H1:NGN-CS_CBRS_RY_PZT2_MASTER_OUT_DQ : PZT2 output  :  2.8e-10 rad/count

I've also attached more spectra recorded this morning after the clean room fans were turned off. Many of the noise peaks went away, especially above 100 Hz, but some lines remain which are common to the seismometers and c-BRS. The DIFF signal above 100 Hz, drops to ~10 picorad/rt(Hz), indicating that it's noise floor is indeed well below the SUM channel. I expect that the current SNR at ~10 Hz is between 10-30. I've attached Matlab code showing the analysis.

[Corey, Betsy, Fil, Peter, Calum, Stefan, Koji]

Summary

- The ISC portion of the HAM6 vent work has been completed.

- Shield isolation of the in-vacuum cables was confirmed.

- The fast shutter was reinstalled on the table after some modifications.

=> Ready for the SEI mass balancing and other exiting procedures. OMC PZT HV is still on. Remeber to turn it off before pumping down.

Some details

- Shield isolation: It is always confusing to check the shiels isolation on HAM6 because of several reasons.

1. All the OMC cables (OMC DCPDs, OMC QPDs, and OMC PZT) are sharing their shield on the OMC breadboard. Therefore one needs to remove the related three DB25 cables from the flange when the shield shorting is checked for them.
2. The beam diverters connects the shields of their cables shorted to the ISI table. Therefore the shorting needs to be checked with the beam diverter disconnected at the mighty mouse connectors. When the test is done, the connectors need to be restored and the function of the beam diverters should be checked again.
3. The picomotors don't short the shields on the table. Check them as usual.

We initially had several cables shorting to the chamber but all of them but one happened at the slack of the cables right inside of the flange. The last one happened on the DB25 cable before it climb up to the vertical wall of the ISI.

- The fast shutter modification / reinstallation

(Photos are supposed to come later.)

1. The new bobbin came in for replacing the moving part of the shutter.
2. The wire stays were modified to have the bobbin wires more relaxed. Also it should allow us to have more clearance of the wires from the beam towards OM1.
3. To allow this modification, the direction of a coil wire (shorter, negative, lower slot) in the terminal block was flipped (Corey's attachment 1).
4. The shutter was placed on the ISI table. Then we found that clearance of the wire is in fact poor. We bent one of the wire clamps (Corey's attachment 2: The clamp at the right side of the shutter) and also adjusted the wire length to have 8~9mm clearance from the beam now. (Corey's attachment 3: The clearance does not look great in the photo but in reality the beam is clearly away from the wire.)
5. The shutter function was tested with the shutter test controller. No HV was used during the test.
6. The beam alignment from the shutter to the gold coated tube was checked. The beam is on the tube but close to the top edge of the tube aperture when the shutter mirror wobbles. We believe this does not create any issue even if the beam falls off from the dump as there is nothing sensitive behind the tube beam dump.
7. Related to the entry  LHO ALOG 28958, we found the shutter height was too low. The distance between the top of the shutter mirror and the beam was ~9mm. The nominal distance is 6mm. We adjusted the height of the shutter to have the nominal height. (Corey's attachment 4)