LVEA is LASER HAZARD

Op Lev - ongoing investigation of ITMY OpLev 

TCS Install - no one present to report

Vacuum - No one present to report

P King - would like to pull cables for ISS. FE LASER watchdog tripped last night. Comments made about aginf NPRO. misc: H1 LASER 'accepted' about 3 weeks ago.

F Raab - suggested some sort of "dashboard" as a visual means to monitor which (sub)systems have passed acceptance testing

Seismic - reported that excess moin in ITMX has been remedied and there will be further investigations into the reason(s) There was a discussion about the 'global' condition of HEPI/ISI world akin o the aforementioned "dashboard"

Commissioning-  Keita will be working on getting the SLED QPDs aligned in the morning and then working on the PRMI in the afternoon to coordinate his activities with the ongoing Seismic testing/investigations.

K. Venkateswara

At UWash, I have built a simple turn-table with two 1.0 kg brass weights controlled by a stepper motor. The angular position of the table is controlled in a 0-90 degree range by a 0-5 V signal applied to the stepper motor controller (consisting of an Adafruit Shield on top of an Arduino Uno). Pictures are shown on page 1 of the attached pdf. The gears and support structure were laser-cut out of acrylic (with our very own 400-W CO2 laser-cutter).

When placed under the beam-balance, the brass weights apply a purely gravitational torque on the balance depending on the angular position. To damp the balance, I take the autocollimator output (angular position of the beam-balance), differentiate it once and band-pass between 3-33 mHz and use it as the control signal after appropriate gaining. The result is shown on page 2.

This setup should work very well with the BRS at ETMX. We could have the damping controlled by the Front-End so that if the beam-balance does get rung up by people in the vicinity it could be remotely damped and the damping turned off once the amplitude is small. Preliminary results indicate that it could even be left on permanently with Q set to 50-100.

model restarts logged for Thu 11/Sep/2014
2014_09_11 00:45 h1fw0
2014_09_11 01:02 h1fw0
2014_09_11 13:12 h1fw0
2014_09_11 14:39 h1fw0
2014_09_11 16:21 h1fw0

four unexpected restarts of h1fw0, h1ldasgw0 was rebooted to resolve the instability.

Did various tests. No dramatic results yet. Here is just a brief summary:

• I could lock PRMI without using the variable finesse technique on the carrier. I used the same settings as the sideband locking except for the sign of the PRCL control
• Moved the spot position upward on PR3 and ITMX by an inch or so while keeping the same spot on PRM and PR2.
  • At this point, POPAIR does not come out to ISCT1 at all. I could not measure the recycling gain, but the BS spot looked dimmer.
  • Though, this definitely reduced the scattering from PR3.
• Moved IM4 angle such that the PR2 spot goes up. This operation seemed quite effective to increase the intracavity power.
  • This is true even for the PRX configuration. Some clipping losses ?
• Tried focusing the PR2 GigE on the infrared objects. I cloud get a better focus. But the PR2 python camera process had been frozen for some reason and therefore I could not get a sharp image.
  • This also happened to the PR3 GigE. They need to be fixed in the daytime tomorrow.
• I implemented a oplev damping loop in the bottom stage of PR3 to supress 0.7 Hz motion.
• The spot motion on the BS seemed better tonight presumably because of the better ITMX ISI and PR3 oplev damping loop.
• The highest build up today was almost the same as the recent best i.e. 3000 counts in POPAIR_A_LF (corresponding to a recycling gain of 15),
• We need to calibrate the ASAIR_A_LF.

Jeff K, Kiwamu,

At around Sep 11 2014 21:49:59 PDT tonight, the frontend watchdog of the PSL tripped.

Although we looked into time series of various power monitors, we did not find a trigger event. The 1st attachment is a 20 sec data of the various frontend-related channels. Since we did not see an anomaly in the data, we went ahead and turned the frontend laser back on by going into the PSL enclosure. It came back fine and the PMC, FSS and ISS locked right away. I attach some screenshots of the status monitors for some future reference.

J. Kissel, R. Adhikari

In attempts to investigate the long-term, sawtooth drift seen in the H1 SUS ITMY's optical lever (see LHO aLOG 13863), Rana and I went out nudged and poked things on the transmitter/ laser launcher side of things. I attach a time series of the optical lever signal over 4 hours, starting at 2014-09-11 2349UTC, or roughly 4:50p local, and explain the timeline below.
- At around 5:44p local (marked in mustard yellow), Rana gave the pylon a couple of hefty nudges to see if anything was loose. This clearly shifted the pylon in yaw, but had no affect on the sawtooth.
- For the next 10 minutes (between yellow and black), we wandered around the LVEA locking for wrenches to tighten down the nuts and bolts connecting the pylon to the concrete. 
- Having found some, we then cranked on all accessible bolts (marked in black). This moved the pylon in yaw some more. 
- Realizing we needed to open the hood to get it realigned (we got no action out of moving the ITM around), we looked for some allen keys (between orange and black). 
- During this time, you could convince yourself that the sawtooth remained. 
- Once we got back, we opened the lid, which pushed the beam off the edge of the QPD (marked in red). 
- We then unlocked the pitch and yaw adjustment micrometers, and re-centered the beam on the ITM (marked in blue). 
- After recovering the transmitter, Rana went to Daniel's for dinner, and I came back into the control room.
- At around 7:25p local, Kiwamu misaligns ITMY to work on PRX cavity locking, so the beam falls off the QPD again (marked in green).
- At 8:10p local, he realigns ITMY into a Michelson configuration -- and voila! sawtooth has reduced.

The message: I think this means that the problem lies in the QPD. Maybe one of the quadrants in bad, such that depending on the location of the spot on the QPD this drift is more or less prominent. I'll try walking the beam around the QPD for the next hour or so before people come back from dinner to see if I can nail down the problematic quadrant.

As was described in alog 13761 (see the addition to that entry) it seemed as if what we see in the POP sled QPDs are not what we expect.

As it turned out, the sled was badly off in YAW such that the beam doesn't come to the sled without using picomotors. I needed to use "magnum" step for moving picomotor in YAW. What we "saw" previously seems to be a lobe of severely clipped beam.

Anyway, using a straight shot beam I'm already getting 1551 counts of H1:ASC-POP_A_SUM_OUT and 1450 counts B (whitening gain 45dB), while the maximum we should get is about 1540 counts assuming 10W through IMC, 3% PRM, 229ppm PR2, 10% through attenuating BS, 1k transimpedance, 45db whitening and 0.8A/W responsivity.

(I'm not using "toW" filter, so these SUM numbers are raw counts.)

Note that centering on QPDA is sort of reasonable, so you should be able to use that reliably for the carrier buildup measurement, but on QPDB the beam is only on one quadrant (S3). I'll continue centering tomorrow.

Sheila, Kiwamu, Rana, Lisa

This plot corresponds to one of tonight PRMI carrier locks (Sep 11 around 3.50 UTC). The recycling power fluctuations are larger than 50%.  PR3 PIT is causing the motion at 700 mHz, ITMX YAW is largely dominating around 100 mHz .

Jim, Sebastien

For the past couple of days, we were seeing extra motion below 100mHz on the ITMX optical lever (especially in Yaw -> almost 1 microradian at DC)

Jim and I spent some time looking at the BSC-ISI, and finally ended up with a better configuration: the motion in Yaw has been reduced by one order of magnitude below 100mHz

New configuration:

- TSheila blends everywhere on ST1

- T750mHz blends on ST2. GS13s in high gain mode.

This improvement should be good enough for tonight. However, those are some premilinary results and there is still some work to do to fully understand what's happening.

It seems (this is just a guess for now) that we were reinjecting some noise by using the GS13s in low gain and  the wrong blends (too aggressive).  We'll have a better look at the ISI performance in different configurations tomorrow.

We also have to compare those results with the other chambers and see if we see consistency. Plus, it would be nice to work on damping the 0.7Hz resonance seen in Yaw.

Work in progress!

As logged here by Kiwamu, there was a reported problem with the BS oplev.  I've now gone through several hours of data and have found no instances of these small (on the order of 20 - 30 counts) changes in the QPD SUM causing the oplev pitch/yaw outputs to behave badly.  After reading this alog, it sounds as if the BS oplev is behaving.  In light of this I'm going to leave the oplev as is.  I will continue to keep an eye on it, and if any problems are noticed during commissioning efforts please let me know.

Dan, Jim, Dave

h1fw0 was becoming unstable (4 restarts today). We stopped h1fw0 and unmounted the file system. Dan upgraded h1ldasgw0 Solaris and rebooted. We restarted h1fw0, here is the data gap in the frame record"

-rw-r--r--  1 controls controls 1232710812 Sep 11 15:40 H-H1_C-1094510336-64.gwf
-rw-r--r--  1 controls controls 1232554615 Sep 11 16:22 H-H1_C-1094512896-64.gwf
 

08:17 Richard and Bubba to the end station chiller yards to look at new VFDs
11:20 Gerardo to the LVEA west bay to move the optic used for the electrostatic charging tests
13:18 Travis to the LVEA west bay to retrieve parts for the staging building
14:20 Jeff K. to end Y to swap cables for the ISI STS
14:45 Jeff K. back from end Y, did not swap cables, fixes need to be made in the model
15:39 Dave shutting down fw0 so that Dan can restart the Solaris box

Dust alarms at monitor #6

Permanent/dedicated AC receptacle for BSC5 annulus ion pump was wired yesterday and now need to get annulus on line

Advanced LIGO Conlog was introduced. The full presentation is available in the DCC. The document number is G1401113.

Some highlights:

* It provides a means to access historical values of control settings. This is accomplished by monitoring and recording EPICS process variables to a database. Searches on this database are made available through a web form and command line client.

* It is designed to retrieve values at a given instant, or changes over an interval (as opposed to continuous trends like dataviewer).

* It can help answer questions like: "I know it was working before, what changed?".

* It is currently available only on the internal CDS network. The web page is at 'h1conlog'. The command line client is called 'conlog_search'.

* There are three different search types available:
1. Return the value, alarm status and alarm severity at a given time:
The value, alarm status and alarm severity of each process variable at the given time is returned.

2. Compare the value, alarm status and alarm severity at two given times:
If the value, alarm status or alarm severity of a process variable differed at two given times, the differences are returned.

3. Find changes in the value, alarm status and alarm severity between two given times:
If the value, alarm status or alarm severity of a process variable changed between two given times, the changes are returned.

* Its status is indicated on an medm screen named CONLOG. This screen can be accessed from the sitemap under the CDS menu.

Please give it a try and don't hesitate to inform me of any issues that you encounter.

H. Radkins, J. Warner, S. Biscans, J. Kissel

Here's a prioritized list of things the LHO SEI Team + Seb intends to tackle (or start tackling) over the next 10 days or so.

(1) Fix problems with ITMX ST1 [[DONE -- aLOG pending shortly]]

(2) (a) Add control of sensor gain and whitening settings to matlab transfer function scripts to ensure they're *always* in the right configuration. 
    (b) Fix blend filter design plots in commissioning scripts to show the blend design MUCH better than it currently does.

(3) Finish commissioning HAM4 and HAM5 ISIs and HEPIs

(4) Support commissioning efforts with "spot" improvements, if possible.

(5) Resurrect Fabrice's Standardized Commissioning Steps list

(6) Use (5) to assess all chambers, to see where we are -- at least with the "fixed" stuff

(7) Gather "current performance" plots for all chambers

(8) Gather HAM2 and HAM3 in-vac, HEPI unlocked, floating, with fluid TFs and HEPI-Position-controlled ISI TFs to help investigation with HAM4 and HAM5 results

(9) Resurrect plant comparison script and use it to compare in-vac transfer functions between HAM and BSC ISIs

(10) Teach Jim and Hugh how to commission sensor correction / feed forward.

(11) Play with Beam Rotation Sensor at EX -- try to get some performance improvements

(12) Think hard about HAM and BSC performance models.

J. Kissel, J. Rollins, S. Dwyer, A. Staley

While Sheila and Alexa began to lock PRMI on carrier, the HAM2 and HAM3 HEPI and ISIs tripped for an unknown reason. We'll leave this to people offline to figure out what happened. See attached actuator trip plots from the ISIs.