Scott L. Ed P. Rodney H.

7/6/15
Beginning this week we increased our crew size by one man. Rodney Haux previously worked for LIGO and has graciously agreed to return and assist with the beam tube cleaning.

Monday was spent relocating all equipment to Y-End where we will begin cleaning and moving toward the corner station. The lights were suspended and fans located for air movement. The crew started vacuuming support tubes and capping them as they were cleaned. 

The 1 ton truck was running extremely rough and it was discovered that the air box was 95% blocked with debris from mice. We were able to remove enough of the material to get the truck down there however, we may need a new air box as this one is very damaged with rodent excrement. I plan on picking up a new air filter today.

7/7/15
Cleaned 59 meters of tube including the bellows in those sections ending 10 meters east of HSW-2-096.

I recently purchased some cooling vest for the crew which seem to be working relatively well. The ice packs only last 3-4 hours at most and then need to be replaced with another set. The triple digit temperatures are taking a toll.    

Chris S. (Joe D.50%)

500 meters of the X-Arm beam tube enclosure have metal strips installed on the upper portions of each joint. We started at the bridge and are working northward.

This has been a slow process in part due to the triple digit heat we have been experiencing.  

While at EX with Jeff K. and Leonid for an ESD issue (alog to come), I restarted the code for the BRS since it crashed during ER7. As expected it was very rung up, so I turned the damper off to let it ring down naturally over the week.

Valved out Turbo pump from HAM6 at 11:45 am, ion pump is mantaining pressure, currently at 4.5 x 10^-6 torr.

Turbo pump + cart still running.

The 18 bit DAC card has been removed from the h1pemmx I/O chassis to update it's firmware.  The h1ioppemmx and h1pemmx models were modified to not include the 18 bit DAC.

All Times in UTC:

14:45 Jeff B out to LVEA to move cleanrooms

15:15 Andres out to LVEA to join Jeff

15:26 Karn and Christina to EY

15:36 Joe into LVEA to check on orklift batteries, Fire Extinguishers, eye-wash stations...etc

15:45 Hugh into the Bier Garden

15:47 Kyle to EY

15:52 Bubba goin to MX and EX

15:56 Karen and Christina leaving EY

16:07 Hugh out of LVEA and heading to EXto replace T240 with STS2.  Back at 17:59.

16:16 Fil out to Ends to do P-Cal power (both) and magnetometer power for Jordan at EY

16:26 Betsy and Travis out to the LVEA to check for post-vent fodder.

16:39 Andres out

16:46 Jeff B out

17:02  Leaving EX cristina & karen 

17:25  Restarting all SEI Models (Kissel)

17:30  Praxair called in to say a truck will be on-site in 15min (for "379" which is MX's CP6) & he mentioned that another truck will be heading to "380" (which is EX's CP8).

17:40  Noticed Beckhoff at EX went down, need to figure out how to remote login and restart.

17:53  pemmx rcg upgrade & pulling a card as well (Dave)

18:05  Continuing Vent clean up in the Cleaning Room (Betsy)

18:06  Heading into LVEA  for hose (Joe)

18:10  TCS Chassis Install at EX & then to EY (Sudarshan, Vinny, & Jordan)

18:20  Gerardo said to keep an eye on EY pressure---any alarm for pressure increase 

18:22  Gerardo on top of HAM6 (for how long?)

18:27  Kyle opening GV5 & GV7

18:38 Sudarshan turning on P-Cal LASER at EX

18:48 Fill reported back from Ends

18:49 Joe into LVEA 

18:50 DAQ restart

19:13 Sheila heading to EX to restart slow controls computer

19:28 Kyle out of LVEA. GV 5,7 are now opened.

19:35 Sheila back from EX

19:48 Fill called from EX. Continuing work for PEM

19:51 Sudarshan back from EX

20:03 Dave re-boot  somthing at EY

20:30 Kyle, John & Gerardo to EY to valve in NEG and valve out Turbo

21:15 John called from EY. Arm is open and Gauges are reading inconsistently. (2orders of magnitude)

21:19 Jordan and Vinny to EY WP 5336

21:20 Katie to EY, Mangetomoeter calibration.

21:21 Fil called from EY. While doing cabling, accidentally disconnected  12V oscillator source.

22:11 Nutsinee out to HAM4 to adjust alignment on HWS table

22:44 Dave and Jim at MX. Took PEM down to remove 18bit DAC.

22:47 Ellie out o HWS table to assist Nutsi

22:48 Jeff K, TJ and Leo to EX to debug ESD issue.

Must have inadvertently unplugged it yesterday while working around this rack

Kyle, Gerardo, John

The NEG pump has been valved into the END Y volume and all appears well.

The plot shows 2 hours of the BSC chamber pressure. Initially the main turbo was pumping the station along with the LN2 pump and open to the tube. The LN2 pump had been opened to the BSC earlier in the day and we let the pressure settle over lunch.

With the turbo still connected you can see the pressure fall as we open the NEG to the volume. Next the turbo was valved out and the pressure returns to near the starting value.

So far so good!

J. Kissel
WP: 5335
ECRs: E1500216, E1500245
II: 1046, 1059
Design aLOG: SEI aLOG 721

Through various levels of changes depending on the whether it was the BSC-ISI, HAM-ISI, or HEPI main library part (see SEI aLOG 721), there are now the following channels in the commissioning frames stored at 256 [Hz]:
HEPIs:
${IFO}:HPI-${CHAMBER}_SCSUM_${SENSOR}_IN_${DOF}_DQ
with ${SENSOR} = either IPS or STS

BSCs:
${IFO}:ISI-${CHAMBER}_ST1_SCSUM_${SENSOR}_${DOF}_IN_DQ
with ${SENSOR} = either L4C, CPS, or STS

HAMs:
${IFO}:ISI-${CHAMBER}_SCSUM_${SENSOR}_${DOF}_IN_DQ
with ${SENSOR} = either CPS or STS
sadly, I only realize after documenting what I've done that the order of "IN" and "${DOF}" is different for HEPI than it is for the ISIs. At this point it's not worth the IFO down time to make the bug fix. Sorry :-(.

This closes out ECR E1500216 and Integration Issue 1046 for Hanford, so I'll reassign it to Monsieur Pele. For Livingston to receive this upgrade, one must only update the following library parts, recompile, install, restart, and restore: 
${userapps}/release/isi/common/models/isihammaster.mdl
${userapps}/release/isi/common/models/isi2stagemaster.mdl
${userapps}/release/hpi/common/models/hepitemplate.mdl

I attach screen shots of the latest version of the relevant blocks in the library parts that I've modified.

Also a bonus change that had been pending until today when I re-found it: the HAM-ISI models had not had their SENSCOR BLRMS channels removed, which I thought have been done when Arnaud was here, as per ECR E1500245 and Integration Issue 1059, but it turns out he only modified the BSC-ISIs (see LHO aLOG 19187). HEPI models never had this calculation, so no need to change there.

For the record, I made sure 
- all SDF differences were understood and captured on all SEI systems before restarting
- all ISC guardians were in their DOWN state, and the IMC_LOCK guardian was OFFLINE before restarting.
- all chambers were brought to OFFLINE via their chamber GUARDIANs
- all chambers were able to be re-isolated after the restart of their front-end process via there chamber GUARDIANs
- add SDF systems for the new platforms have no channels "NOT FOUND" or "NOT INIT" -- because I removed the BLRMS of the STS channels from the BSCs, they required the re-saving and re-loading the SDF table, i.e. an OVERWRITE of the EPICS DB TO FILE, where the file is the safe.snap.
- The IMC recovered after the restart of the HAM2 and HAM3 chambers

Dan, Dave, Jim:

WP 5333

A reminder, just before ER7 Dan found data errors between a Q-Logic fiber-channel switch in the MSR and its corresponding machine in the LDAS server room. The error started after the tape robobt was moved from the CUR to the VPW and its data was added to the DAQ switches. We tried repacing fiber optic cables (did not help), and then Dan purchased new SFPs for both ends of the long haul. In the mean time for ER7 we effectively bypassed the defective switch, sending all the data through a second switch in the MSR. In order to do this, a short multimode fiber link was made between the MSR switches. End of history lesson.

Today Dan reactived the original single mode link and deactivated the multimode inter-switch link. Within the next hour fw0 crashed twice, so unfortunately it does not look like the single mode SFPs were the problem. We have gone back to the ER7 configuration.

STS2-B (ITMY) was sn109827.  STS2-A (HAM2-actually located in BierGarten on temp cable) was sn89950.  109827 has moved to endX to replace the T240 that has been there for some time.  This T240 will relocate to the ETF lab.  There is no instrument connected to the STS2-A chassis and sn89950 is now connected to the STS2-B chassis.

All temporary cable to accommodate the T240 as well as the T240 chassis remain in place.  The T240 chassis is powered off.

Laser Status: 
SysStat is good
Front End power is 32.8W (should be around 30 W)
FRONTEND WATCH is GREEN
HPO WATCH is RED

PMC:
It has been locked 13 day, 21 hr 9 minutes (should be days/weeks)
Reflected power is 2.5 Watts  and Power in Transmission= 22.6 Watts.
(Reflected Power should be <= 10% of Power in Transmission)

FSS:
It has been locked for 17 h and 34 min (should be days/weeks)
TPD[V] = .98V (min 0.9V)

ISS:
The diffracted power is around 6% (should be 5-9%)
Last saturation event was 2 h and 28 minutes ago (should be days/weeks)

NOTES: FSS TPD V is due for a tweaking.

This is Hannah Fair.

I’ve been investigating the FF LSC locklosses from ER7. The following are my findings so far.

About half of the FF LSC locklosses had a 20-25 second oscillation in one of the PRM and SRM channels, and in the PRCL and SRCL channels (and occasionally MICH). The start of this oscillation ranged between around -2000 seconds to only -100 seconds before lockless. All of these ended with one of the channels saturating. This saturation appears to be the cause of loss. This pattern is independent of laser power.

• 1117665437.75 and 1117743020.38: The 20-25 second oscillation appears to be begin approximately 100 seconds before lockloss. In both cases, this ends with the saturation of PRM_UR

• 1117898344.25: The 20-25 sec oscillation begins around -85 seconds. SRM_M3_UL saturates

• 1117946874.25: The oscillation begins at least -500s. There also appears to be beat pattern. Each envelope is about 100s long. PRM_M3_UR saturates.

• 1118022123.88: The oscillation begins at least -500s. A beat pattern with an envelope about 200s long. ETMY_UL saturates.

• 1118088249.75: The oscillation appears to last for several hundred seconds, most evident in PRM and PRCL. Beat pattern has envelope of around 350 seconds. ETMY_UL saturates.

The following are locklosses where I also looked at OPLEV channels (Due to timing, I was unable to look at the data from the OPLEV channels for the locklosses before this):

• 1118207893.12: This was a short lock, so the ~25s oscillation seems to be present throughout. Looking through the OPLEVs, there was a very defined peak around -600s in BS_M3_PIT, ITMX/ITMY/ETMX/ETMY_L3_PIT. PR3_M3_PIT also has a continuous downward progression from lock to lockloss. ETMY_UL saturation causes lockloss.

• 1118213355.125: This is very similar to the previous lockloss. Short lock, about 1000s long. Same oscillation throughout. PR3_M3_PIT has continual decline, and very defined spike in same channels as before around -862 seconds. ETMY_UL saturation causes lockloss.

Some of these are less detailed/precise because of timing and my inability to access data more than two weeks old.

Examples of this pattern are attached as images.

The h1boot, cdsfs0, and cdsldap0 servers were rebooted this morning between 08:00 and 08:30 PDT.  The h1boot was powered off, power cords removed for 30 seconds, then power reattached and powered up. No fsck was performed.  The cdsfs0 computer was patched late yesterday afternoon, and was rebooted this morning.  An fsck on the root file system was performed with no errors.  The cdsldap0 computer was also rebooted, no fsck was performed.

Evan, Kiwamu, Jenne, Stefan

- DRMI alignment is back to the old-good one: strategy: Used old slider values for everything but large optics. Tweaked SR3 (for instance) to get the beam spot centred on ASPD. Aligned PRX using PRM and PR2.
- DRMI ASC worked except PRC2 loop (didn't further investigate because we didn't care without the arms)
- Then we focused on MICH freeze:
  - We fine-tweaked the transfer function using a zpk([0.03],[0.054],1,"n")gain(0.555556) filter.
  - This made the gain roughly 1 below 0.1Hz. Plot 1 shows that - if measured coherently - we win up to a factor of 10 reduction at 0.01Hz. (Blue: no MICH freeze, red: MICH freeze)
  - In terms of RMS reduction (position) of the power spectrum, we gain a factor of 2, at the cost of significant noise injection at 8Hz. (Plot 2)

Interestingly, this RMS is now small enough that we spend most of the time in about 1/3 for the whole simple Michelson fringe. Unfortunately there is still slow drift, so parking at a "good" position isn't quite possible. But we are definitely in a regime where simple "fringe velocity" isn't a good parameter by itself. Fringe position must matter too. In our brief attempt to see locking performance changes we didn't notice anything significant though.

However, the next time we have high winds, we should definitely re-evaluate MICH freeze.

The ISS ref signal was changed from -2.01 V to -2.09 V which in turn changed the refracted power from 15% to about 5 %.

Inner Loop

ISS Inner Loop has  UGF of 22 KHz with a phase margin of about 50 degress. This was measured with variable gain set at 6 dB for the best phase margin. This is the normal operation settings for Inner Loop.

Outer Loop

Outer Loop has a UGF of 1 KHz ( designed for 4 KHz) with a phase margin of  about 30 degrees. The variable gain was set at 40 dB (max available) and an additional gain stage(?) was switched on as well.

Also tried moving the the Inner loop gain to see if it shows any improvement on the outer loop but no luck.

TF Plots are attached.

Calibration Team

Sign of h(t):

The gravitational wave strain h(t) is given by  h(t) = Delta L/L where Delta L  is is computed using

                         Delta L = ± (Lx - Ly)

The sign of Delta L can be determined using Pcal actuation on the test mass. Pcal only introduces a push force  so pcal readout signal (truly pcal excitation) is minimum when the testmass is away from the corner station (closer to pcal laser). From the first plot the phase between DARM/PCAL is ~ -180 degrees (DARM lags PCAL) which suggests that DARM signal from ETMX will be maximum when pcal is minimum (ETMX further away from corner station). Similarly, from second plot, since DARM and PCAL have a phase difference of ~-360 degrees (essentially 0 degrees), the  DARM signal from ETMY is minimum when the pcal is minimum. This shows that the sign convention for the Delta L is '+'

Time Delay between Pcal and DARM:

Also the slope of the curve gives the time delay between Pcal and DARM signal chain. The time delay is about 125±20 us. This time delay can be accounted for, within the uncertainity, from the difference in signal readout chain outlined in Figure 3 attached.

Refer to LLO alog #18406 for the detailed explanation behind this  conclusion.