I have been working on using the lower stage sensors (L1 and L2 OSEMs together with optical levers) to get information about the longitudinal displacement of each test mass of a quadruple suspension. I have been experimenting with trying to match up yaw signals on the quad because this degree of freedom is relatively uncoupled, unlike pitch or longitudinal. The results are somewhat promising, except for an unexplained factor of ~10 difference between the OSEMs and optical lever data. More information can be found in this report on the DCC:

https://dcc.ligo.org/LIGO-T1300957

The matlab code that was used to generate plots in that document is

/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/Diagnostic_sensors/generate_damped_yaw_models.m

I will be taking doing maintenance on the LHO aLOG today at 12:15pm
Pacific.

Please have all entries posted to the logbook or saved to a draft before
12:15pm.

It will NOT be safe to work on an entry after that point until I have
sent an all clear notification (which will include a comment on this aLOG entry).

If everything goes smoothly the aLOG will go through a few phases:

* total outage (a few minutes)
* read only while the system is being verified
* back to normal use

The work will not extend the functionality of the aLOG.  It is a
operating system upgrade and a relocation which will be a step towards
making the LHO computer users room an overflow for the control room.

The file server cdsfs0 became unresponsive this morning.  Power cycled the computer, the file server restarted and is functional again.  Cause is unknown at this time.

This alog should be filed on last Thursday's date. 

Last Thur, Calum and I cleaned the ITMx suspension and BSC chamber surfaces (IPA and wipes).  We pulled the First Contact on the CP-AR, ITMx-HR, and the little 1" witness plate attached to the structure.  (We had reinforced the FC the day before, via painting over the ITMx-HR windows and spray-cone-ing the CP window.)  We then checked a few DOF TFs on the ITMx and exited.  The West door was promptly put on.

On keita's (and daniel and stefan's) suggestion, I went back into the PSL to check on the ref cav power budget.  

First I measured the AOM diffraction efficiency, measuring with the filter:

Before the AOM there are 34.5mW, after single pass there is 19.6mW, after the second pass there is 14.05mW,  40% double pass efficency.  This has degraded since christina's meassurement of 72% in Link  I measured the RF power to the AOM by first disconecting the input to D1201423 (VCO AOM driver in PSL racks), then connecting the cable to the AOM (after the blue SLP-100) to an RF analzyer, then reconnecting the input to D1201423.  there is 30dBm of 79Mhz.  According to Christina's alog it should be 1.2W, I'm not sure if the 0.2W matters.  Since the cable was attached to the AOM verry tightly and the translation stage moves, I could have disturbed the AOM alingment in the process.  

Measuring without the filter, there were 11.9mW incident on the ref cav (after the circulator), and 6.9mW in transmission.  I measured 11.3mW after the circulator when the REFL PD DC ( measured using the lemo cable connected to the TNC DC output) had 66.4mV above the dark offset of 0.8mV.  When the cavity is locked, there are 14mV above the offset on this PD, meaning we have 2.4mW of power in reflection.  This means we are loosing 18% of our power somewhere.  We are probably loosing a few percent in the circulator, but that is at most 5%.  

[Jeff K Arnaud P]

Quick summary of TFs taken today on HAUX (IM1 IM2 IM3 IM4), TIp Tilts (RM1 RM2) and TMSX, following 8709. Quads and HSTS are (almost) done and will be processed tomorrow.

HAUX (1st pdf)

IMs are consistent from one to an other, but are slightly different from the model. Looks good though, probably just a model issue.

HTTS (2nd pdf)

-RM1 has its resonances matching the model. RM2 has an extra resonnance in Yaw.
-RM1 and RM2 do not roll off the same way, and it might be due to the eddy current dampers, poorly tuned.
-Calibration between both sites is still suspect, because of confusion in the electronics chain. Transconductance of HAM-A driver used in the script : 9.6 [mA/V], and 20 / 2^16 [Vpp / ct] for the 16 bit DAC
 

It may be good enough for now, but we should keep an eye on those next time the chamber will be opened.

TMSX (3rd pdf)

TMSX looks fine, and in good agreement with the model and the measurement before the centering of the osems and balancing of the table (cf alog 8705).

Data and scripts will be commited under the svn tomorrow.

Thanks to the HEPI model update (see alog#8703), the alignment offsets will now be installed into the cartesian basis.

Thus, on HPI-HAM3 and HEPI-HAM2, I recalculated the alignment offsets used to lock the IMC a couple of months ago into the good coordinates.

Here's the procedure to do so:

- turn off the IPSINF inputs.

- put the IPS readouts value that you want to go to in your IPSINF_offsets (same sign)

- turn on the IPSINF offsets

- copy the BLND_IPS<DOF>_IN1 value in Target (DC_BIAS screen)

- After you turned on the position loops, if you copy paste the Target value into Current Setpoint, HEPI should go to the wanted position.

New snapshots with the new Target  values have been saved. They'll be found in the svn at:

/opt/rtcds/userapps/release/hpi/h1/burtfiles/

Gerardo M, Mike V, Mark and Randy from Apollo and Mitchell R

Today the ETM-Y Cryo baffle was completed and installed into the tube. The baffle was balanced and ready just before lunch allowing for a post-lunch install. The installation of this baffle was one of the smoothest of the 3 I have been apart of. Great job to all those involved your hard work payed off. The lower copper plate which are part of the Eddy current damper system has yet to be added. These parts had minor modifications done to them and will begin the bake cycle tomorrow. Most tools and hardware has been cleaned up. Final cleanup will take place tomorrow. The teflon pads have been removed from the install fixture allowing it and the balance fixture to be removed from the end station at any time. 

Symetrization filters and damping loops have been installed on BSC-ISI ITMX (without any issue).

Kyle

I had left the combined volumes purging over the weekend-dry air entering XBM purge port and wet air exiting IMC purge port which I had left blanked minus a gasket-good flow, i.e. effective purging -> This morning I found that the LVEA Purge-Air drying tower had malfunctioned at some point over the weekend (Check valve stuck open, will fix asap) such that only the right drying tower was completing the drying/regeneration cycle while the left tower wasn't at the correct pressure during its regeneration phase -> I isolated the VE from both purge connections and measured the dewpoint of the purge air header at the IMC purge connection to be -18C when on the malfunctioning tower and -21C when supplied by the working tower (-6C ambient air) -> Next, I measured the dewpoint of the "Blowdown" air exiting the ~1 psig VE while the purge air header was isolated and found it to be -25C  

~1430 hrs. local -> Started "attended" rough pumping of HAM2,3,BSC1,2,3,7 combined volumes (NOTE to self: have unused 1.5" angle valve on BSC7 dome open to its NW blank and unused XBM 6" gate valve open to its 8" blank during roughing -> will need to close these when switching to turbo)

~1630 hrs. local -> Halted "attended" pumping via closing O-ring valve on turbo header -> will resume tomorrow

Hanford Fire onsite all morning testing fire alarms in OSB

1000 EX to laser SAFE

1030-1400 Sheila and Kiwamu working in PSL enclosure

1345 Justin adding distilled water to crystal chiller for PSL diode room

Kiwamu, Sheila

After the transition to science mode on friday the temperature in the PSL enclosure has stabilized, now the daily fluctuations are about 1 degree F and the 20 min oscillations are completely gone (bottom right of attached screen shot).  The laser power (top right) is slightly more stable, and 20 minute oscilations in the ref cav trans are completely gone (lower left). 

We will stay in science mode unless someone is actively inside the PSL.  

Kiwamu and I went in this morning (we transitioned to commisioning mode first) with three goals: Kiwamu wanted to investigate the status of the rotation stage, to try to reduce the comination of the PMC trans camera with light from the reference cavity, and to search for reasons for the ref cav misalignment/ fix it.  

The image on the PMC trans camera is clearly different when the ref cav is locked and when it is not.  We confirmed that this is not due to a stray beam coming at a large angle but something that travels almost along the same direction as the PMC trans beam.  There is also a large "smudge" in the image.  We found that by blocking the power meter on the PMC refl port we got rid of the smudge. TIlting the power meter slightly did not move the smudge position on the trans camer at all, although it did seem to reduce the amount of power in it.  It seems as though this is light that is scattered into the PMC reverse propagating mode from the power meter, and then clips somewhere on the way to the trans camera.   

We also seem to have light from the reference cavity in this "smudge".  This could be because the reference cavity circulator is slightly off, and some of the reflected light gets back into the PMC in the counter propagating mode.  We did not try to adjust the quater wave plate, but it is possible that could help.  

In the end we added an iris before the PMC trans camera, there is still a difference between the on screen image with and without the reference cavity locked, but it is much better and the centroid position calculated by Chris's script is almost the same when the ref cav is locked and unlocked.  A picture of the camera before and after the iris was added is attached.  For future reference, on the PMC trans camera up on the table looks like down on the camera, and vice versa.  

We then moved on to looking into the ref cav alignment.  We tried taping and pushing gently on the optics in the path from the PMC to the ref cav, nothing was obviously loose and the alignment always returned to where it was when we took our hands off.  We noticed that the beam shape after the EOM was bad, and when we looked at the aperatures on the EOM the beam seemed high.  We brought the EOM up, which improved the beam quality.  When we were done adjusting the EOM we had (with the ISS disabled) 12.9mW incident on the EOM and 12.6mW after.   This clearly misaligned the reference cavity, we recovered the alignment using the camera and the iris at the front of the cavity as references, and adjusting the top periscope mirror and M27 in pitch.  We were able to get back to about 0.6V on the transmitted PD by walking the beam once the cavity was locked.  We expected to be able to get more than 0.9V, so something is still amiss.  Also, the spot position on the reflected camera has moved.  This does not make sense because there is no reason the reference cavity position should have moved (we think) and the beam is aligned to the cavity.  When the cavity is locked we see bassically nothing in reflection right now, and the spot position on the trans camera down't appear to have moved much.

We then realigned the ref cav reflection PD, using the DC power on a scope.  Kiwamu noticed that the value on the MEDM screens for the refl DC was not changing while I did this.  It seems as though the input is grounded in the model, he is looking into how we can get this recorded in the digital system.  

The EOM misalignment could have been a symptom or a cause of the problems we have been having.  We decided to leave things be for now, and have a look at trends over thanksgiving when no one should be going into the PSL and the PSL is in science mode.

Last week there were issues noted with the Picomotor cable for EX TMS, and it was traced to mislabeling of the (4) Mighty Mouse connectors on a D1000238 cable (basically you want the Mighty Mouse closest to pin-1 of the 25-pin connector to be labeled "D" (@ EX it was labeled "A"). 

I went ahead and confirmed that our (6) remaining D1000238's were labeled correctly (they are), and then also marked the shell of the DB25 with a "1" on its outer surface close to where pin #1 is (see attached photo).  This is because it's impossible to confirm the orientation of the DB25 (or where pin#1) is when it's connected to another cable and screwed down to a cable bracket.  So, if one marks the outside of the connector it's easy to determine the orientation of the connector without unplugging everything.

guardian/cdsutils deployment

We [Jamie, Dave and Jim] recently deployed initial releases of the guardian and cdsutils software packages at LHO:

• guardian - the main guardian codebase
• cdsutils - python library and cli for CDS interaction, including ezca channelaccess library. the cdsutils python library is a depndency of

A more complete description and usage of these packages is described (or will be) on the awiki links above, but very briefly:

cdsutils is ageneral purpose tool for interacting with the CDS system that is meant to include much of the commonly needed functionality that used to be available in the old ezca/tds name space (read/write/switch/avg/etc). It is both a python library, and a CLI that wraps some of these functions for use at the command line:

controls@operator0:~ 0$ python -c "import cdsutils; print cdsutils.avg(2, 'H1:LSC-DARM_OUT')"
{'H1:LSC-DARM_OUT': 0.0}
controls@operator0:~ 0$ cdsutils avg 2 H1:LSC-DARM_OUT
H1:LSC-DARM_OUT 0.0
controls@operator0:~ 0$ 

See 'cdsutils --help' for a brief usage.

guardian is the in-development aLIGO automation system. The 'guardian' program itself serves two purposes:

• interface to execute a single state from a guardian system state machine description module.
• launch the guardian state machine engine daemon for the state machine described in a guardian system module

See also 'guardian --help' for command line usage.

installation

Both cdsutils and guardian were installed in /ligo/apps, and should be available for all users:

controls@operator0:~ 0$ which guardian
/ligo/apps/linux-x86_64/guardian/bin/guardian
controls@operator0:~ 0$ guardian --version
guardian svnr308
controls@operator0:~ 0$ which cdsutils
/ligo/apps/linux-x86_64/cdsutils/bin/cdsutils
controls@operator0:~ 0$ cdsutils --version
cdsutils svnr95
controls@operator0:~ 0$ python -c 'import ezca; print ezca.__file__'
/ligo/apps/linux-x86_64/cdsutils/lib/ezca.pyc
controls@operator0:~ 0$ python -c 'import cdsutils; print cdsutils.__file__'
/ligo/apps/linux-x86_64/cdsutils/lib/cdsutils/__init__.pyc
controls@operator0:~ 0$ 

For the moment they are installed directly from the SVN, but as they stabilize they will be installed from properly versioned releases.  The svn checkouts for both packages are in "/ligo/svncommon/CdsSVN/":

• /ligo/svncommon/CdsSVN/cdsutils -> https://redoubt.ligo-wa.caltech.edu/svn/cdsutils
• /ligo/svncommon/CdsSVN/guardian -> https://redoubt.ligo-wa.caltech.edu/svn/guardian

h1guardian0 setup

Infrastructure for management of guardian daemon processes was setup on h1guardian0.  This system manages the starting and stoping of guardian daemon processes, and logging their output.

The guardctrl tool, included with the guardian installation, is for interacting with the above described daemon supervision system.  It includes commands for creating, starting, stopping, restarting, etc. the daemons, and for accessing their logs.  It can be executed from any CDS workstation, and communicates with the setup on h1guardian0 via ssh.

the control room workstation opsws7 (behind the operator station) appears to have a bad fan. It is turned off and will go out for repairs soon.

Since the TMSX TF was OK according to JeffK, I and Corey went into the chamber and removed the temporary alignment stabilization tooling.

I made sure that nothing is left on the TMS ISC table.

Transitioned the ETMy HEPI Actuators to Run mode.  We are ready.

Mike V, Gerardo M, and Mitchell R

Saturday we were able to complete the primary baffle assembly and transferred to the balancing fixture. Current steps now are to complete the balancing process and transfer assembly back to the installation fixture. This should be completed by mid-late afternoon today. This would ideally mean that the Cryobaffle assembly will be ready for install Tuesday. 

[Jim, Sebastien]

This week, we've seen the gain of L4C-H2 changing randomly, from nominal gain to a factor of 2 lower.

We tried to chase down this issue without success (see aLOG #8632 and 8666). Everytime we tried something, it magically resolved by itself, and there were no way to reproduced it.

After it happened again today, we might have found the issue though: the in-air cable at the feedthrough felt a little "squishy" and loose. Jim unplugged it and readjusted everything. It feels much better now, and the issue is once again gone.

According to what we saw before, we're pretty confident that was it. If it wasn't, let's keep in mind to start looking at the feedthrough when it happens again.