Kyle, Gerardo Legacy pumps long past their nominal life expectancy -> Damaged knife edge of 2 1/2" O-ring isolation valve at HAM2 ion pump attempting to align flanges which were kept sprung misaligned by rigid non-perpendicular piping -> Had to remove damaged valve and replaced it with an elbow (will repair valve in house and keep as spare) -> Leak tested new joints -> Will now need to pump with pump carts for a few more days before energizing new ion pumps. Note: HAM1/HAM2 annulus volume was fully vented for a period of time -> no pressure change in Corner Station
Added 326 channels. Removed 57 channels. The following 10 channels are unmonitored: H1:GRD-TCS_ITMY_LOGLEVEL H1:GRD-TCS_ITMY_MODE H1:GRD-TCS_ITMY_NOMINAL_S H1:GRD-TCS_ITMY_REQUEST H1:GRD-TCS_ITMY_REQUEST_S H1:GRD-TCS_ITMY_STATE_S H1:GRD-TCS_ITMY_STATUS H1:GRD-TCS_ITMY_TARGET_S H1:SUS-SR2_LKIN_P_OSC_SW2R H1:SUS-SR2_LKIN_Y_OSC_SW2R
Scott L. Ed P. Chris S. 52 meters of tube cleaned today from single door towards X-1-6 double doors. Continuous motioning of beam tube pressures during cleaning operations.
I'm sitting in for Jeff who left early to go on vacation.
15:55 Kiwamu going to close the LASER shutter to HAM1 to do some testing on the rotation stage.
So what was supposed to be a simple favour for Aidan to turn the CO2y laser on turned out to be not so simple. Note: when I started this work I was unaware of the issues that Greg encountered last week (he has just put in an alog now for me alog 17302).
So at the moment the CO2y laser is still off.
Below is what observed/thought was the problem before hearing from Greg about the issues he saw previously (and is now alogging) , and also talking to Aidan about his recollections. Also will include what I think is going on for part of it and also recommendations.
Observation 1:
The rotation stage for CO2y is not working (I cant get it to do any rotation of any kind). I played with this before knowing that Greg had seen this last week also. I did not try playing with the CO2x. Based on past experience at LLO and LHO its going to be something with Beckhoff having to be reset (we really need to work out why these things just stop working). So until it is up and running I dont want to turn the laser on. And because I dont know how LHO like to proceed with doing procedures like this I took this no further. So what I need is for someone (maybe at start of next weeks maintenance period) to reset the HWP for me (probably just needs to be unplugged then replugged).
Observation 2:
I went out to the mechanical room to check the status of the power supplies etc. I immediately saw two things that peaked my interest.
1. Only one of the Kepco power supplies is on and wired up?? and the one that was on was drawing no current (see pic Kepco power supply). This I have seen before and indicates that one of the AOM drivers has faulted. But because things look to be hooked up weird (will discuss more later) looking on the tables I see that CO2y AOM driver is fine (indicated by the two green LEDs..see pic CO2yAOM driver), but the CO2x AOM driver has faulted (top LED red...see pic CO2xAOM driver). If you want to know what these fault lights mean please go to E1500133 and look at table 1 (someone should probably print this table out and stick it on or near the AOM driver for others for future reference). Now this has been seen before at LLO and the solution is to power cycle the power supply. However doing this will make the AOM start to work, and seeing as its not known when it faulted and what static diffraction setting the driver has been set to, once the reset occurs I could alter how much power is going to the interferometer (as CO2x laser looks like its being used). So again this is something should do during maintenance period (should note what power going to optic now and so when reset see how/if it changes and alter power accordingly).
2. The CO2Y laser power supply seems to be drawing a funky amount of current. 2.5Amps actually (see pic TCSy power supply), even though the laser is off. Ive even turned the key on the controller off, so it shouldn't even be in standby mode where only draws 0.7Amps. Talking to Aidan he seems to think that maybe the AOM driver/AOM is drawing current from this supply (him telling me that made me recall we saw numbers like this back in the day when we were installing and the laser was off but we had the AOM driver on). He seemed to recall the AOM driver and CO2 laser are driven off the same supply still here at LHO (which was the original design), even though the plan was to change to having the CO2 laser and AOM driver driven off separate supplies (as has been implemented at LLO...the Kepco power supplies power the AOM drivers the other supplies power the CO2 laser only). But this doesnt seem to totally match with what Im seeing in the mechanical room.
So looking at the wiring, here is what I think is the current setup at LHO. We are in some funky mid change between having one power supply do both laser and AOM driver and having separate supplies for all. In more detail......The two shelves showing the power supplies for TCS are shown in TCSracklowershelf and TCSrackuppershelf. How it should be as per the latest plan that I know of (and is at LLO) is that the on the lower shelf should hold the power supplies that power one table (ie say Y ) and for the upper shelf the power supplies for the other table (X) with seperate supplies for the lasers and the AOM drivers. What seems to be the case is that:
*on the lower shelf we have the Instek supply (I think thats the brand name....its the the one with the digital readout reading its drawing 2.5Amps that says TCSY on top of it) powering BOTH the CO2y laser and the CO2y AOM driver (I think this because the laser is OFF, as is the controller, but the AOM driver on the Y table has not faulted and is "running".The x table AOM driver has faulted and is not "running" and 2.5amps is an approximate number that the AOM driver could be drawing).
* The Kepco power supply on the lower shelf is wired up but not drawing any current at the moemnt and thus and looks to be powering the AOM driver for the X table (why... because the x table AOM driver has faulted its not drawing any current). It should be wired to be controlling the Y table if supply in the position at..or at the very least labeled clearly as to what it is powering. Mind you I could be wrong and its powering something else
* The instek supply (the one showing the digital readout of 22.42 Amps) on the upper shelf is powering ONLY the CO2 x laser (its drawing this current as the laser is on).
*The Kepco power supply on this upper shelf is not even wired up and is thus off.
What I suggest is at some stage when have some time (maybe during maintenance period next week), is to wire the system as per the new design (and as how is at LLO). One Kepco power supply is used for the AOM driver on one table and the other Kepco power supply be wired to the AOM driver on the other table. And then just have the other power supplies individually controlling the CO2 lasers. Should then also have the power supplies for one table on one shelf and the power supplies for the other table on the other shelf.
Also when turn laser back on need to see if still only drawing half the current like Greg saw and if so investigate (probably cable connection is the problem like in the past). SO quite a few things would lile to do at next weeks maintenance period.
10 days ago, Gabriele and Evan reported that there seemed to be a large offset in the IMC locking loop (alog 17131). In order to investigate this issue, I started from checking the health of the IOT2L optical table -- specifically we wanted to confirm that there is no stupid clipping or something crazy.
I did not find a clipping or anything crazy on the table.
(Health check of IOT2L)
I went to the IOT2L and checked the REFL path using a IR viewer and card, but I did not find an obvious clipping or any suspicious things. I found an iris which was letting the main beam go through but also scattering ghosts beams. The iris was in front of the BS which steers the beam to the REFL RFPD. I took out the iris and re-adjusted the razer blade beam dumps which have been meant to damp those ghosts. Also, I checked the centering of the beam on the REFL RFPD by steering the BS, but it was already centered.
(What happened to MC trans digital camera ?)
BTW, the IMC trans camera had been displaying nothing these days according to the hourly archives probably since some time in February. I realigned the camera as it seemed to be misaligned in YAW. After adjusting the exposure, I realized that the beam shape completely changed from the image that I remembered -- see the attached pictures. The first attachment is the one from Feb-04-2015 and the second from today after my realignment. During the realignment process, I moved the camera position to see if this image is something bogus or real. I am concluding that this image is real. Something must have happened in the IMC trans path between early February and now. Sad.
Hugh and Krishna had found the BRS software had crashed pretty much on schedule, so Sheila and I went to the end-station to restart it. Pretty straightforward. Alogs 13817 and 15005 will get you everything you need to do it. The BRS is rung up right now because we went out to check the mass damper positions, but it should settle down in 30 minutes or so.
K. Venkateswara
I took a look at the BRS_RY_IN channel and it looks like BRS started to get damped but then the damping failed (see attached pic). It is currently oscillating with 500 count ampitude. I'm not sure why this happened but it currently looks like the mean position of the damping turn-table has changed by 45 degrees causing it to neither damp nor drive BRS. A repositioning of the turn table might help. If not, I'd suggest turning off the damper temporarily.
Looks like Jim and Sheila did everything right, but the damper is a bit finicky.
Looks like it did damp down eventually. I have no idea what happened, but it is possible that the damper turn-table got stuck, moved to a new mean location and then somehow got stuck again and returned to a reasonable location. In any case, looks like BRS is damped now and working well.
LVEA: Laser Hazard Observation Bit: Commissioning 07:00 Karen & Cris – Cleaning in the LVEA 08:22 Hugh – LVEA for HEPI maintenance work 08:36 Jodi – In the LVEA for 3IFO stuff 08:37 Christina – Forkliftng boxes from LSB to VPW 08:45 Jim B. – Starting work on the NTP server move 08:45 Matt – Turning on CO2-Y laser 08:50 Richard – Vacuum survey in the LVEA 08:51 HFD on site testing fire alarms 08:55 Kyle & Gerardo – Swapping out Ion pumps on HAM1 & HAM2 09:00 Peter, Jason & Ed – In the PSL for RefCav and FSS work 09:01 Corey – Working in the squeezer bay 09:34 Richard – Going to End-Y with HFD to test fire alarms 09:51 Hugh – Finished with HEPI in LVEA – Working on pump controller. 09:52 Jodi – Out of the LVEA 10:00 Praxair delivering N2 to Mid-X 10:03 Paradise Water on site 10:30 Filiberto – Working on TCS-X RF cabling 10:48 Richard – Back from End-Y 10:55 Kiwamu – Checking IOT2L for beam clipping 11:00 Doug – Looking for OpLev parts near HAM2 11:00 Peter, Jason, & Ed – Finished in the PSL 11:05 Reset HEPI watchdog counters 11:38 Dave – Restarting new PEM corner station model & making cable changes in CER 11:42 Kyle & Gerardo – Out of the LVEA 11:50 Dave – DAQ restart 11:50 Kiwamu – Out of the LVEA 12:35 Karen – Going to End-Y 12:35 Cris – Going to End-X 12:43 HFD on site testing smoke alarms at End-X 13:10 Kyle & Gerardo – Leak checking at HAM1 & HAM2 13:51 Karen – Leaving End-Y 13:52 Filiberto – Connecting TSC RF cables 13:55 Kiwamu – Checking mirror pointing in IOT2L 14:22 Filiberto – Out of the LVEA 14:30 Kiwamu – Out of the LVEA 14:41 Jason – In LVEA getting parts from the OpLev cabinet 14:56 Jason - Out of the LVEA
We have turned off 3 LVEA heaters today as the winter season departs. It appears that temperatures in the LVEA are now back to nominal after an excursion of ~0.5F.
12 hours shown on the plot.
We'll continue to monitor the response.
I collected my performance data with the BSC in the right blend configuration this morning (sans modified blend filter, from my alog earlier today) and updated the HAM spectra from Friday, with slightly better color choices, I hope. See attached pdfs.
This is an issue from last week. While doing chiller maintenance last week I noticed that the power supply for the TCSx laser was running at only half power. I checked the cables and didn't find any obviously loose connections, but this has been an issue in the past. Less likely, but still possible is the RF driver failing. While on the table I noticed the rotation stage has once again gone glitchy and won't respond to requests or return to home. Most likely requires a Beckhoff reset. There is and has been a beam block in the laser path. For now the TCSy laser is disabled by the MEDM gate.
Actually the TCSy is disabled by turning the key off also at the control box (I didnt know about these issues at the time when I started trying to turn the CO2y laser on today (alog to come)).
Also like Greg mentions I would suspect the cable connection if is onlydrawing half current as this has been a known issue on this table before see alog 16495.
P. King, J. Oberling, E. Merilh
Summary
FSS RefCav TPD started drifting again, went in to re-align. Check mirrors M23, M22, and M21, all found loose. M23 and M21 pitch adjustments recovered RefCav TPD, M22 had no effect; all pitch adjustment screws locked. FSS RefCav TPD left at 1.56V. Adjusted M36 to optimize power incident on PMC_TRANS PD, now reading 23.03 W (up from 22.99 W). Measured FSS TF, UGF measured at 195 kHz.
Details
The FSS RefCav TPD had begun to drift down again, so we went in and checked the remaining 3 mirrors in the FSS beam path: M21, M22, and M23. We first checked M23 and found the pitch adjustment screw to be loose. Turning this screw CW (pitching the mirror down) caused the RefCav TPD to change from 1.23V to 1.53V; the adjustment screw was locked. M22 was also found unlocked, but did not effect the RefCav Trans; this adjustment screw was also locked. The final mirror in the FSS path that we had not inspected before was M21, and lo-and-behold, the pitch adjustment screw was unlocked. Turning this screw CW (pitching the mirror down) took the RefCav TPD from 1.53V to 1.56V; this adjustment screw was then locked. We will continue to monitor the FSS RefCav TPD.
Since the transmission through M23 is responsible for the PMC_TRANS reading, we slightly tweaked M36 to optimize the reading of the PMC_TRANS PD. Before the adjustment the PMC_TRANS was reading 22.99W, it is now reading 23.03W.
Finally, we took a TF of the full FSS loop, and measured the UGF to be ~195 kHz. Peter has the full TF data and will add it as a comment to this post.
Checked and set all LVEA Supply Accumulators to 70psi; Return Accumulators set to 20-30psi.
Issues found at H(am)5R(eturn), H6S(upply), H5S, H4S, B(SC)3E(ast)S,B3W(est)S,B3WR,B2N(orth)S(unable to charge due to interference), B2NR, B1NS, B1SR, H3S, H1S, H1R, H2R.
Wow, maybe easier to list the ones that did not need some gas. Most of the Supply units that needed charging where at 20psi or below. This should make a good improvement in pump pressure fluctuation coupling into to platform motion. I expect next check should see a much shorter list.
Found that someone had decided to store unused 2" Angle Cable Tray Support Assemblies under BSC1. Sliding these in, the Feet on the Assembly was just the right height to hit the valve knob and turn it. Fortunately, the drain exit is capped and no leak occurred. Please mind the caution tape and be aware of the pushing and pulling things in and around the low dark places where HEPI resides.
Noticed that the Vacuum Pipe, Instrument Air Piping and Conduit are all contacting the SR3 OpLev Transmitter Pier near its base. This is just East of HAM4 on the North Side.
Reset the watchdog counters for HAM2, HAM3, HAM5, ITMX, and ITMY
I got a chance to test the modified blend filter that JeffK and I came up with on Friday(alog 17256). It looks like it most does what we expected. Attached plots show X, Y and Z dofs for both stages., dashed lines are the before, solid lines are after, red is St1, blue is St2. I don't show it, but there was no change in performance below 1 hz. I think we might be able to push the elliptical filter down a little more, get some improvements closer to 5hz, but that will have to wait while I run down other projects.
I've installed this on ETMY, ITMY and ITMX, but it's only running on the Y arm chambers, for now.
A side note, the blend filter banks for the BSC's are getting a little weedy. It's probably getting to be time to do a little clean up and make things more consistent between chambers.
Sheila, Nutsinee
Attached below are the plots of PEM/ALS and PEM/ISI correlations. Using data from March 14 (we had high wind up to 45 MPH). The x-axes are wind speed in mph, the y-axes are either ALS-X(Y)_REFL_SCTRL_OUT_DQ (rms) or ISI-ETMY_ST1_FFB_BLRMS_(DOF)_(100M or 300M)_(300M or 1) (mean). The correlation (r) is calculated and printed in the parentheses. Since PEM-EX and ALS-Y seems to correlate the most (r=0.7783) I only plot the correlation between PEM-EX and ISI-ETMY for the PEM/ISI correlation. PEM-EX and ISI-ETMY-RY (100-300 mHz) appears to have the highest correlation (r = 0.7469).
A Matlab script also attached.
My apology for the lack of axes labels earlier. I have attached better plots below....
Also, note that PEMEX, PEMEY, and PEMCS is in X, Y, Z direction (not locations). Also, the "ISI-ETMY_ST1_FFB_BLRMS_(DOF)_