(Kiwamu I., Dave B., Chris W.) Under work permit 3874, today we copied over the recently committed l1ascimc model changes at LLO (see LLO alogs 7040, 6986, 6936), and rebuilt the h1ascimc front end code. This closes out the part of WP 3874 that pertains to h1ascimc. However, the WP remains open until h1psliss is rebuilt as well, see below for details. Library parts updated Since the L1 model makes use of recently revised WFS and QPD_WITH_WHITEN_CTRL library parts (LLO alog 6878), we first had to update the library parts in the isc/common/models directory. The following parts were affected: U QPD.mdl U ALS_END.mdl A OAF_FILTER.mdl U RF_PD.mdl A RF_PD_WITH_BECKHOFF.mdl U FILTBANK_TRIGGER.mdl U WFS.mdl Updated to revision 4477. It appears that the changes to the ALS_END and RF_PD library parts are cosmetic, and will not affect other front ends when they are rebuilt. The H1 models that will have functional changes due to these library updates are the following: QPD_WITH_WHITEN_CTRL: h1ascimc, h1psliss FILTBANK_TRIGGER: h1lsc WFS: h1ascimc, h1iscey h1psliss will be rebuilt by Dave Barker at a later time (to be coordinated with the PSL crew). h1iscey will be rebuilt soon by Kiwamu and I, and its WFS parts will be removed completely. h1lsc will be copied over from LLO after the l1lsc model stabilizes. Temporary local mod to h1ascimc The new l1ascimc model introduces a power normalization factor for the IOO WFS. This factor is designed to come from the l1lsc front end via an IPC link. But for the moment, we prefer to keep the h1ascimc and h1lsc models decoupled from each other. That way, we can wait for the l1lsc model to stabilize before trying to merge it. So in the meantime, we got rid of the IPC link, and replaced it with a temporary EPICS input called H1:IMC-PSL_PWR_REQUEST. This will be set to 1 watt for the duration of the HIFO-Y test. As soon as we bring over the lsc model from L1, the IPC link to ascimc should be put back in place. Housekeeping The updated h1ascimc model has been checked in to the SVN. MEDM screens, safe.snap and filter coefficient files will be soon be updated and committed in concert with LLO.
Day's activities:
PCal work in LEA---going to Laser Hazard (Pablo, Rick, Michael R.)
Weather Station name change work & checked connection at MX(Patrick)
Installing optics on IOT2L (Kiwamu/Chris)
HAM4 work (cleaning chamber/cleanroom, craning items, etc)
Fixing timing issues with LVEA Test Stands (Jim B)
Pulling Cables for ISC
LSC/ASC update to their models (Chris/Kiwamu/Dave)
BSC3 ISI installed on Test Stand
ETMy measurements (Szymon, Fred)
Robert performing beam tube measurements at the end of the shift (Kiwamu is his buddy for the evening)
Maintenance Visitors: Snow Valley onsite for work on the arms, Paradise, Oxarc filling CP1
15 days of pumping is shown in the attached plot.
Several annuli remain to be pumped down.
HAM1, HAM2 - since HAM 1 is vented this annulus system(HAM1/HAM2) cannot be evacuated. Provided there are no big leaks this should be ok.
HAM 4 septum - liikewise HAM4 is vented so the septum annulus cannot be evacuated. Same comment as above - ok but not optimum.
BSC1, 2, 3 not yet evacuated.
A comparison of the pumpdown curve for the yend and the LVEA which both have a full
test mass chamber assembly give the following pressure vs time dependences on the
assumption of a 1/t water emission law:
2.3 x 10^-5
LVEA P(tdays) = ----------- torr
t(days)
5.0 x 10^-6
Yend P(tdays) = ----------- torr
t(days)
The pumping speed ratio for water and hydrocarbons becomes
F(LVEA)
-------- ~ 1/4
F(Yend)
The LVEA volume includes one ITM/ISI assembly, one BSC/ISI assembly, and two HAM ISI assemblies with all their optics and cabling. HAM1 is NOT part of this volume due to the septum in place.
ENDY has the one ETM/ISI assembly.
The transfer functions measured between the T240s of stage 1 and the GS13s of stage 2 (ISI-BSC6) are presented in attachment. Transfer functions were measured with the ISI damped and excited by the ground motion. Coherence between the 2 stages in the translation DOFs are really good when the damping filters are engaged. These transfer functions can be used to realise the sensor correction from stage 1 to stage 2 (Translation only). Yesterday, I used the ratio of simulated transfer functions when the ISI is damped for the computation of the match filters.
HAM cleanroom was cleaned twice in preparation for the BSC3 ISI move to the test stand. The test stand also received another wipe down with particular attention to the risers that come in direct contact with the ISI. The ISI was flown to the test stand and the test stand cleanroom moved over the top of it. HAM4 and the cleanroom around HAM4 got first cleaning today.
25 Days of pumping.
The DAQ was reconfigured to use the new weather stations channel naming scheme. Where possible, the raw minute trend files were renamed such that old data is not lost in the transition. This required several restarts of the DAQ. The new h1ascimc model install also required a DAQ restart due to a changed INI file.
In an effort to correct timing errors on the test stand computers in the LVEA (problem since the power outage early April), I powered off h1oaf0, h1susquadtst, h1susbstst, and h1seitst computers and I/O chassis, then power cycled the timing slave and IRIG-B. I waited for the the timing slave to sync up and the IRIG-B unit to start displaying the correct time. Then the I/O chassis were powered on, followed by the computers. With the exception of h1susbstst, the models started up with no timing errors. h1susbstst started with a large IRIG-B time offset, and the models showed timing errors. I powered the computer down, power cycled the I/O chassis, then powered up the computer again. The timing remained in error. I killed the models, then started the IOP model by hand. The timing was off, and the ADC and DAC indicators were all red. The IOP ran for several seconds, then the GPS time stopped incrementing. I powered off the computer and I/O chassis and gave up. This will take some more troubleshooting. Also, I moved the IRIB-B feed for the x1dc0 computer on the DAQ test stand to the DTS IRIG-B unit in the H2 Electronics room. It was being fed from the LVEA IRIG-B unit by a very long cable, left over from the H2 DAQ system.
Attached are plots of dust counts requested from 5 PM May 12 to 5 PM May 13.
This is a late alog from yesterday: I swapped the links for the internal and external PDs on the fiber distribution box. As Daniel noticed, they were backwards. The powers right now are: from PSL screen ref cav trans PD= 2V (is this calibrated somewhere?) 7.7mW in fiber input to ALS fiber distribution box (the BNC monitor on the front says 0.52V, and the internal PD in beckhoff reads 2.17 V) 0.76mW in sample output 0.58mW in X arm 0.52mW in Y arm 0.446mW in squeezer beam In the MSR there are 0.4mW, and the end station PDs report 0.170mW total with 22uW in the rejected polarization The external PD was saturated at 10V in beckhoff when I first looked at it, and the BNC output on the fiber distribution box was 13V. Then the reading in beckhoff dropped to 4.6V, and the BNC reading dropped to 0.6V. The lights in the PSL enclosure seem to be on. The PDs in this box use the photodiode amplifier D1200543, but the gain is set by hardware switches in the box and not controlled by beckhoff so we are calling them DCPDSimple in beckhoff. The test report says the gain is set to 30dB, this means the transimpedance is 20000 Ohm.
The backup file server cdsfs1 has been crashing over the weekend. I performed an fsck on its file system today (no actions were needed) and was able to rsync cdfs0 and h1boot before it crashed again at 5pm. I'll reduce the rate of rsyncs back to daily and look into buying a spare raid controller card.
Aggressive isolation filters were designed on ISI-BSC6. UGFs are:
- 40Hz on all stage 1 DOFs
- 32Hz on all stage 2 DOFs.
The simulink diagram was completed to perform the sensor correction from stage 1 to stage 2. The model was recompiled and installed on h1seiey. Spectra were measured in the following configurations:
- Stage 1 super sensor with T240s blended at 250mHz on all DOFs.
- Stage 2 super sensor with blend at 250mHz on all DOFs.
- Sensor correction on both stages (except on Stage 1 Z)
Calibrated spectra of stage 2 are presented in attachment. Results are good.
The 2 high pass filters used for the sensor correction create a x10 amplification below 100mHz. It is less visible in the Z direction since the sensor correction is only engaged on stage 2.
in SusSVN/sus/trunk/Common/Matlabtools :
in SusSVN/sus/trunk/Common/Matlabtools/SchroederPhaseTools :
In SusSVN/sus/trunk/QUAD/Common/Matlabtools
The 3 directories have been commited on the svn
Apollo crew moved BSC Repair Arm, HAM Install Arm, 5-axis Table, and other install tooling to the south side of the beamtube between HAM10-11. Christina wiped down the BSC3 ISI storage container and the Apollo crew moved the HAM cleanroom over the beamtube and set it down close to the storage container.
Activities of which I was informed about:
- Hugh at Y-end station, HEPI work.
- Apollo crew, moving items with crane from south bay area to the West north wall area.
- Cheryl, Input viewports cleaning, see her entry.
- Pablo and others inside H2-PSL room, Pcal work.
- Patrick to the LVEA to check on dust monitors.
MitchR, JimW
After several furious hours of helicoiling, forklifting, placing bolts and torquing, the last 2 large plates for the first (formerly-known-as-H2) I1 BSC ISI were added to the assembly today. Next up, everything else: pods, actuators, cps's... Potentially, we could be testing sometime next week.
Restarted dust monitor at location 8 in the LVEA. I found it turned off outside of a small clean room between HAM 2 and HAM 3. Looking at the trends it appears someone turned it off this morning.
I used FC on both input viewports, ALS and PSL. Both viewports looked significantly better after cleaning - at least a 95% reduction in features. The remaining 5% are probably particulate that reattached after I pulled the FC, but could also include stubborn particulate that didn't come off, or features in the optics coating. This was my first look at the ALS viewport, and it did have a fair amount of particulate on it. The ALS shutter has removed some anodization inside it's housing. My rookie venture into spraying FC meant there was some to clean up around the edge of the optic on both viewports. Though I was careful, it's possible the solvent I used to clean it up (methanol) could have migrated residue under the flange. When we have the new shutter, we should consider removing the viewports and doing a more thorough cleaning and inspection in the optics lab. I have no idea what level of risk, if any, this would be to the optics themselves. I cleaned what I could reach inside both shutters. *** I locked the PSL shutter closed *** Filiberto and crew were planning to pull cables about the HAM1/2 enclosure, so this is now laser safe for their work.
BSC 1 is now added to the list of chambers flushing, with HAMs 2, 3, and BSC 1 now being flushed in the LVEA. The max pressure we've been able to attain has been about 29 psi, this is with running the pump to max and backing down a little. Air has been caught in the resistors and is being purged on a regular basis. The system works.
HAM2 actuators have been switched into the operating state. HAM3 and BSC1 continue to be in the flushing state.
We leveled the optical path from the laser to the first MCL PZT mirror, but things didn't improve much.
The first Faraday transmission is fine (first picture, EOM and the second Faraday removed from the path, picture taken in front of the second lens).
EOM transmission is ugly when the beam passes through the middle of the input and output aperture (second picture).
After fiddling around with the EOM alignment using 4 DOF stage, we always ended up with the beam very high on the input side. (no picture).
After the EOM, when the second Faraday was inserted, it makes many ghost beams /halo in PIT (third picture). This vertical pattern doesn't change much with alignment.
Using an iris, we can get rid of most of the ghost beams (last picture). The central part of the beam is not totally round, this comes from the EOM. This looks somewhat better than OAT days (sadly).
Anyway, since it is convenient to open up the iris to see the retro reflected beam from ETMY, we left all irises wide open.
The Faraday makes many ghost beams for the refl beam too, but all of these seem to fall on the PD.
We measured the power level right at the laser, downstream of the first Faraday, downstream of the EOM and downstream of the second Faraday. Jax will post the numbers.
We have removed some unused optics from ALS table.
One 50/50 green splitter (labeled as such on the mount) and one green high reflector (ditto) were put in the ISC cabinet in the squeezer bay together with things labeled "ALS WFS stuff".
One green high reflector didn't have any label, but it was easy to see that it was a high reflector. To avoid future confusion, I removed the optic and put it back in the original mirror box from Precision Photonics.
It seems like there are other unlabeled optics in "ALS WFS stuff" bunch, and maybe on our tables, but we should do better. PP optics are not labeled anywhere, the only visual clue for the reflectivity is the color of the coating, and some people might have a difficulty identifying which is which.
Make labels and put them on mirror holders or posts.
Power measurements as promised:
From laser: 42.5 mW
After first Faraday isolator: 35.5 mW
After EOM: 31 mW
After 2nd Faraday isolator: 28 mW
After 2nd PZT mirror: 26.3 mW - after inserting another iris this measured 27 mW, likely within the bounds of measurement error.
Note that there is a 10% pick-off for Hartman sensor path between the 2nd PZT mirror and the periscope.
All in all, the efficiency from the laser to the chamber is something like 0.9*27mW/42.5mW = 57%, which is consistent with June 2012 alog (61%) as well as July 2012 alog (0.9*20mW/30mW=60%, note that the measurement was done upstream of 10% pick off in July 2012).