Tested the cables at the Sat. Amp connector to Ground. Verifying Pin 13 Was attached to Shield then Pin 13 to Ground. H1:SUS_ETMX-1 PASSED H1:SUS_ETMX-4 PASSED H1:SUS_ETMX-7 PASSED H1:SUS_ETMX-16 PASSED H1:SUS_ETMX-19 PASSED H1:SUS_TMON-1 Failed. Showed short to ground somewhere between Sat Amp and OSEM. H1:SUS_TMON-4 PASSED
Hugh Radkins and Richard M Tested the ETM-X ESC cable. Hugh was kind enough to work inside the chamber while I checked the connection from outside. ON first inspection 3 out of the 5 pins were making contact. Hugh removed the connector then reseated it rocking it back and forth as he inserted it. This seemed to work. He then tightened the connection alternating between screws until the unit was tight. I retested all of the pins and we have connection through the system.
h1oaf0 was powered down to add a additional ADC and DAC to the IO Chassis. The computer remains down for now due to the EY systems being offline
At EY, h1susey, h1seiey and h1iscey are down to rearrange the cards in their IO Chassis to match the EX configuration.
Patrick, Kiwamu
This is a follow-up work of the PSL power control rotation stage (see #8606). The punch line is that:
This morning, we installed a +/- 24V power supply cable to enable the relay circuits for the interlock. This power cable connects the interface box, which is currently sitting on the PSL table next to the periscope (see #8606), and a LIGO-standard power strip underneath the PSL table. I confirmed that it lighted up an LED on the front panel of the interface box. Then I connected the two-pin motor power and DB15 cables at the Beckoff chasis which had been disconnected 10 days ago (see #8593) for a safety purpose. To plug them back in, I powered off the chasis for approximately a minute. Then, I powered it up again after I plugged them.
We tested the rotation stage to see if it is functional. At the beginning, because the interlock was at the disable position (the mechanical switch was in its down position), the rotation stage didn't move at all regardless of what kind of command I sent. This is good as this is how it is supposed to be. Then we switched the interlock to the enable position by toggling the switch. This then allowed the rotation stage to move. So it is working fine and ready to go.
Note that, at the moment, the rotational stage doesn't have a waveplate in it. Plus, the stage is sitting aside the main path, so it is not going to do anything for the main beam.
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 upgrade is complete. This comment is to verify that the L-mail works.
Maintenance is largely done. There is one outstanding issue, the L-Mail notifications are no longer working. Feel free to use the aLOG, but note, the mail notifications may not be working.
Mail notifications are working. The aLOG maintenance is complete.
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.
We also laid a new witness plate just beneath the ITMx QUAD on the floor - this should be pulled promptly at the next vent and sent to CIT for analysis.
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.
IMs are consistent from one to an other, but are slightly different from the model. Looks good though, probably just a model issue.
-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 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.
That has to be some sort of record. Nicely done!!!
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.
