Today the injection locking of the high power oscillator (HPO) was not as good prior to the water
leak on Wednesday.  We examined the overlap between the front end (FE) and the HPO and tweaked it.
The beam profile appeared to improve as a result.  The reference level for the injection locking
was altered from -1.20V to -1.30V.  The injection locking appeared more robust with this setting.
No relocks were encountered during the lunch break.

    Using the high power attenuator, the output of the HPO was reduced to ~29W as measured by the
water cooled Ophir power meter on the table.  The beam was aligned to the pre-modecleaner (PMC).
Initially the reflection locking photodiode output was:
  L02 position = 61 mm on rail, 10 on micrometer
  unlocked = 922 mV
    locked = 185 mV
  visibility = (unlocked - locked ) / (unlocked) = 79.9%
We moved the mode matching lens L02 towards the HPO.
- L02 position = 56 mm on rail
  unlocked = 917 mV
    locked = 95 mV
  visibility = 89.6%
- L02 position = 49 mm on rail (this is as far as we could move it because another mount was in
                                the way)
  unlocked = 907 mV
    locked = 95 mV
  visibility = 89.5%

~26W was measured after the IO EOM.  This value is consistent with the PMC visibility.

    The frequency servo was locked after a minor tweak to the vertical alignment of the beam.
~60 mW was incident on the reference cavity.

    Things are by no means optimised.  All servos were left running as a test.  Obviously both
the FE and HPO are running.  The relock counter was reset, the power watchdogs for both lasers
have been engaged.  Autolock for the frequency servo was left dis-engaged.

    The values for the PMC transmission reported on the MEDM screens are out of whack.  There
are a few other signals that need to be checked out too.

    We will crank up the power to the PMC next week.

 Should the laser(s) trip for some reason, do not attempt to resuscitate them! 


Jason, Peter

Not pumping HAM6 chamber over the weekend because we found a leak on east door. We will need to pull off door to repair o-ring leak on Monday if leak rate is too big. Quantifying leak rate early Monday morning, after leak checker has had time to run and stabilize. North and South doors passed leak check test. 

Michael, Krishna,

No significant wind-storms yet. As discussed yesterday, in the quiet conditions (0-10 mph), when we tried to use sensor correction on the 90 mHz blend, we improved isolation in the 0.1-1 Hz region, but increased rms motion of the platform (as seen by the CPS) in the 10-30 mHz region. We tried to see if we could do a better trade-off.

We have been using a broadband sensor correction filter (Mitt_SC), originally made by Rich M. for the Z direction. After a few iterations, we came up with the filter shown in the first pdf, named Mitt_SC3. It has more gain-peaking in the 20-70 mHz region (where we get the best tilt-suibtraction), but suppresses motion below 20 mHz by a factor of ~3. I guess it will approach the Hua filter ultimately if we wanted even sharper roll-offs.

The attached pdfs show the result of this filter at EndY and EndX respectively in plots which have the same format as before. In this case, the overall rms of the CPS sensors is the same or smaller when using SC as compared to the 90 mHz blends alone. We still have a factor of 2-10 isolation improvement in the 0.1-1 Hz band as measured by the T240s on stage 1.

(Richard M, Filiberto C, Kyle R, Gerardo M)

"New" high voltage cable was pulled yesterday along with new fiber.

The cable was tested yesterday, hi-POT tested up to 5k, then both ends terminated.

Fiber was tested today, all good.

Today the power supply was setup on the shelf and powered on, ion pump is working good thus far.

Day Shift Summary:

Title:  04/08/2016, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT)
State of H1: IFO unlocked. HAM6 vented for ISI upgrade. 
Commissioning: 
Outgoing Operator: N/A
 
Activity Log: All Times in UTC (PT)

15:00 (08:00) – Start of shift
15:45 (08:45) Jeff k., Jim, Corey – Working at HAM6
15:55 (08:55) Peter, Jason, Ed – Working in the PSL
16:15 (09:15) Patrick – Working on the End-X vacuum computer for new gauge install
16:30 (09:30) Patrick – Restarted the End-X vacuum computer
16:35 (09:35) Jeff K., & Evan – Confirmed the fast shutter is operating & out of LVEA 
16:40 (09:40) Filiberto & Manny – Going to End-X to recover tools
16:42 (09:42) Jim & Corey – Finished at HAM6 – Out of LVEA
17:37 (10:37) Patrick – Restarted the End-X vacuum computer
18:00 (11:00) Kyle, Chandra, Gerardo, Jeff B. – Reinstall north and south HAM6 doors
22:00 (15:00) Kyle, Chandra, Gerardo, Jeff B. – Out of the LVEA
22:40 (15:40) Kyle, Chandra – Starting pumping and leak checks on HAM6


End of Shift Summary:

Title: 04/08/2016, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT)
Support: 
Incoming Operator: 

Shift Detail Summary: SEI upgrades are finished. TFs for HAM6 look good. Reinstalled the north and south doors on HAM6. Vacuum group is pumping down and doing leak checks.  

   Took many particle samples inside the chamber and inside the cleanroom while installing the north and south doors on HAM6. There was one spike of over 2000 counts of 0.5um particles while putting in the bolts on the bottom of the north door. There were also a couple of elevated counts when covers were removed. All other readings (inside and outside of the chamber) were below 100 0.5um particles, with most below 50 0.5um particles.

   A 4" witness optic was placed on a mass stack just to the -X, -Y side of the OMC. 

   The cleanrooms from the north and east side have been powered down and returned to their parking spot. The Main cleanroom over HAM5/6 has been shutdown; the power cable has been disconnected. The temporary power cords for the cleanrooms have been removed from under the chamber. 

   The small garb room and cleanroom on the south side are still running. I have some work to do on Monday that requires a cleanroom. These will be shutdown and removed when the leak checks are finished. 

Ymid:  3:40-3:50pm local time

Took 2:34 min. to overfill CP3 today with half turn on bypass valve. 
Next fill due Monday, April 11th.

Top plot:

IM2 LR OSEM noise rises above other IM OSEMS around 135Hz.

At 570Hz, IM2 LR OSEM in blue in top plot is ~15x the noise of the IM3 LL, ~60x the noise of IM1 UR, and ~90x the noise of IM4 LR

Bottom Plot:

OSEM noise shows up in pitch signal

Kyle, Gerardo, Jeff B., Chandra

East door was installed on Thursday. North and South doors were installed today. Two of three are torqued. We will torque the South and start the rough pump down after late lunch. 

NOTES:  

1. North door has a questionable scratch along the o-ring sealing surfaces (but not wide enough to cross both o-rings at same time, we think). Scratch is in fourth quadrant (when looking at door).
2. Inner o-ring of South door was bad. We replaced with one from 1998 processed stock. 

We will leak check all doors before COB today.

Filiberto, Patrick

We did two things, and it is not clear which or if both were necessary. We swapped the transmit/receive fiber pair into the CU1521 media converter at X2-8. After that the link lights started blinking. At the end station we changed the rotary dial on the CU1521 media converter from 0 to 5. This dial sets the direction of the media converter as seen from the EtherCAT master. 0 is from fiber to copper. 5 is from copper to fiber. (pg. 22 of http://download.beckhoff.com/download/document/io/infrastructure-components/cu15xxen.pdf) So it had been incorrectly set as from fiber to copper. We then power cycled just the CU1521. We had checked the dial on the media converter at X2-8 and it was correctly set to 0 (fiber to copper).

I had to restart the Beckhoff controls and IOC again to scan and add the gauges. I called Cheryl from the end station and she ran a script on the vacuum computer in the control room to set the IOC values. She also set the CP LLCV control to manual. I just set it back to PID.

My watch on Operations: approx. 18:00-20:00UTC (11:00-1:00PT) - as of 20:56UTC:

• 18:11UTC - Kyle, JeffB, Chandra, 4th person - reinstall HAM6 North and South Doors - currently putting on the South door
• 18:30UTC - Fil and Patrick - EX-28 to look at fibers - done
• 19:00UTC - PSL team out for mid-day break - currently Jason and Peter are in the PSL
• 19:47UTC - Fil and Patrick to EX - vacuum controls, restarted Beckoff - currently Patrick is monitoring the PID for CP8

The h1nds1 computer died with a kernel panic.  I powered the computer off, then powered it back on at about 11:53 PDT.  Monit needed to be told to monitor the daqd process once the computer booted.

Corey and I did the last few ISI items this morning in HAM6. Check for tools, wiped down areas where people were working, pulled the septum cover, unlocked the ISI and closed the chamber. While we were doing that Evan, JeffK and Fil checked the operation of the beam diverter and fast shutter (Jeff just alogged that). I've now taken closeout ISI measurements and the ISI looks ok. I think my measurements are made a little noisy by high purge flow in the chamber, so I may take longer measurements after the chamber closes. But I think we are good to put doors on.

J. Kissel, E. Hall, F. Clara

As per this April HAM6 vent's plan, E1600092, we've confirmed the functionality of the AS AIR and OMC REFL beam diverters, as well as the HAM6 fast shutter. Details of the test below. The tests required turning on the HAM6 High Voltage for the shutter, but we since have turned it off again now that or tests are complete.  All mobile ISC components are functional; ISC is a go for chamber closeout.

------------------
Beam Diverters:
- The AS AIR and OMC REFL beam diverters did not need to be moved or disconnected at all during this vent, so testing their functionality was as simple as exercising the OPEN/CLOSE buttons on the corresponding Beckhoff MEDM screen and watching as the shutters cycled through the two positions. We were able to cycle both several times without issue.

Fast shutter:
To test the fast shutter we did the following (informed by LHO aLOG 17831)

This scenario: The chamber doors are open, the shutter is clearly visible, ISCT6 has been pulled away from the chamber, the trigger PD's input has been disconnected from the remote chassis, and the high voltage has been turned off.

Gather ahead of time: a portable DC voltage supply (it need only be capable of +5V) and associated BNC cable and adapter.

Process:
(1) Confirm that the HAM6 fast shutter remote chassis's power is OFF (both that the front-panel "HV Enable" little silver dip-switch is set to "disable", and the back panel power rocker switch is OFF). This chassis is located in the field rack just -Y of HAM6 at the bottom of the rack.
(2) Turn on the high voltage power supply in the Computer Electronics Room (CER) Mezzanine. Since the voltage and current adjust are analog dials, they are typically left at the right setting, so one only needs to turn on the power switch to the power supply. Once on, the voltage readback should show 250V, and the current readback should be hovering just above 0 A (i.e. *very* little current should be drawn).
(3) Return to the field rack, and turn on the back panel chassis power rocker switch.
(4) On the front panel, you should see the +/-15V light green, the computer screen light up, and after a few seconds the fault light will go red.
(5) Enable the HV from the front panel silver dip switch. The computer screen will indicate that the capacitator is charging up for ~10 sec or so. The fault light will remain on.
(6) Connect the DC voltage supply (with no voltage output) to the Fast Trigger Input. 
(7) As soon as you give the voltage supply 5 V, the shutter should pop up, and the fault light will go off.
(8) Cycle the 5V a couple of times to confirm expected functionality. If the shutter pops up and down as expected, then the shutter is functional.
(9) Disconnect the 5V voltage supply, flip the sliver dip switch back to "disable," turn off the power to the chassis via the back panel rocker switch, and turn OFF the high voltage power supply in the CER mezzanine.

NOTE This only tests the mobility of the shutter, it does not test the shutter logic or the timing. This requires ISCT6 to be in place, and light on a trigger PD, as per LHO aLOG 17831 cited above. We will test these critical components as soon as possible.

The Diagonal Volume is currently being pumped by the Turbo, IP7 and IP8.  IP7's voltage setting is not optimal, I'll fix it later.  Unless otherwise directed, will leave this way over the weekend and shut down the Turbo Monday.

I put the TwinCAT system into configuration mode at end X and scanned for devices. The media converter and X2-8 EtherCAT gauge did not show up. I put it back to run mode. The LLCV is in manual mode until the PID recovers.

Related alogs 26264. 26245

I did some follow-up tests today to understand the behavior of the DARM cavity pole. I put an offset in some ASC error points to see how they affect the DARM cavity pole without changing the CO2 settings.

I conlude that the SRC1 ASC loop is nominally locked on a non-optimal point (when PSL is 2 W) and it can easily and drastically changes the cavity pole. The highest cavity pole I could get today was 362 +/- a few Hz by manually optimizing the SRC alignment.

[The tests]

This time I did not change the TCS CO2 settings at all. In order to make a fair comparison against the past TCS measurements (26264, 26245), I let the PSL stay at 2 W. The interferometer was fully locked with the DC readout, and the ASC loops were all engaged. The TCS settings are as follows, TCSX = 350 mW, TCSY = 100 mW. I put an offset in the error point of each of some ASC loops at a time. I did so for SRC1, SRC2, CSOFT, DSOFT and PRC1. Additionally, I have moved around IM3 and SR3 which were not under control of ASC. All the tests are for the PIT degrees of freedom and I did not do for the YAWs. During the tests, I had an excitation line on the ETMX suspension at 331.9 Hz with a notch in the DARM loop in order to monitor the cavity pole. Before any of the tests, the DARM cavity pole was confirmed to be at 338 Hz by running a Pcal swept sine measurement.

The results are summarized below:

• SRC1, offset = from +400 to -300 cnts, cavity pole = from 350 Hz to 275 Hz
• SRC2 , offset = from +0.2 to -0.2 cnts, no change
• DSOFT, offset = from -0.03 to 0.03 cnts, no change in cavity pole, but a noticeable drop in the power recycling gain (41 --> 39).
• CSOFT, offset = from -0.03 to 0.03 cnts, no change in cavity pole, but a noticeable drop in the power recycling gain (41 --> 38-ish).
• PRC1, offset = from -0.1 to 0.1 cnts, no change in cavity pole, but a noticeable drop in the power recycling gain (41 --> 38-ish).
• IM2, some large offset, no change in cavity pole.
• SR3, offset = +/- 50 urad, no change in cavity pole or recycling gain.

The QPD loops -- namely CSOFT, DSOFT, PRC1 and SRC2 loops -- showed almost no impact on the cavity pole. The SOFTs and PRC1 tended to quickly degrade the power recycling gain rather than the cavity pole. I then further investigated SRC1 as written below.

[Optimizing SRC alignment]

I then focused on SRC1 which controlled SRM using AS36. I switched off the SRC1 servo and started manually aligning it in order to maximize the cavity pole. By touching PIT and YAW by roughly 10 urads for both, I was able to reach a cavity pole of 362 Hz. As I aligned it by hand, I saw POP90 decreasing and POP18 increasing as expected -- these indicate a better alignment of SRC. However, strangely AS90 dropped a little bit by a few %. I don't know why. At the same time, I saw the fluctuation of POP90 became smaller on the StrioTool in the middle screen on control room's wall.

In order to double check the measured cavity pole from the excitation line, I ran another Pcal swept sine measurement. I confirmed that the DARM cavity pole was indeed at 362 Hz. The attached is the measured DARM sensing function with the loop suppression taken out. The unit of the magnitude is in [cnts @ DARM IN1 / meters]. I used liso to fit the measurement as usual using a weighted least square method. 

By the way, in order to keep the cavity pole at its highest during the swept sine measurements, I servoed SRM to the manually adjusted operating point by running a hacky dither loop using awg, lockin demodulators and ezcaservos. I have used POP90 as a sensor signal for them. The two loops seemingly had ugf of about 0.1 Hz according to 1/e settling time. A screenshot of the dither loop setting is attached.

This is an update of the DCPD cross correlated spectra. This time I have added the one from Livingston which was integrated over 1266 hours using the O1 data. High noise durations (e.g. LLO 23453) are excluded from the integration.

The fig and mat files are attached.