FYI: in that rack, the +15V pulls ~0.5 A more than -15V usually. I think this is due to some RF amplifiers which are powered by this (e.g. the AOM that Manasa set up). The Sorensen's can source ~30A in principle, so we should make sure to set the current limit appropriately so as to not overheat them when there is a short.
Was this power supply not fused for all of its connections? I remember that this was connected to at least one un-fused connection in the past year.
+15V supply powers the following (from what I see):
1. PMC and MC boards on the rack.
2. RF amplifiers on the rack for the beat signals from the green beat PDs.
3. Beatbox itself.
The beatbox was the one that had an un-fused connection last year. I re-did it properly to go through a fuse quite sometime ago.
I dont see any other un-fused connections now from the +15V supply right now.
P.S. AOM driver takes a 0 to +28V power supply and not connected to the +15V
Q and Steve will follow elog 10028 entry to prepare the vacuum system for safe reboot
Here's the sequence of the morning so far:
The IFO is still down, as the PMC won't lock without the rack power, and we haven't pinned down the shorting mechanism. We don't want the replacement sorensen to immediately blow when plugged in.
Vacuum safe reboot required one hour of no pumping of the vac envelope.
This is going to be a big one. We're at version 2.5 and we're going to go to 2.9.3.
RCG components that need to be updated:
Things to watch out for:
We want to measure the pressure gradient in the 40m IFO
Our old MKS cold cathodes are out of order. The existing working gauge at the pumpspool is InstruTech CCM501
The plan is to purchase 3 new gauges for ETMY, BS and MC2 location.
Basic cold cathode or Bayard-Alpert Pirani
Dec 21, 2010 we pumped down the MARK4 rebuilt 40m-IFO and the malev has been pumping on it since than
I was lucky to notice that the nitrogen supply line to the vacuum valves was leaking. Closed ALL valves. Open supply line to atm. Fixed leak.
This was done fast so the pumps did not have to be shut down. Pressurized supply line and open valves to
"Vac Normal" condition in the right sequence.
I decided to see what was inside the sensor that had been previously made. According to elog 1102, the temperature sensor is LM34, the specs of which can be found here:
The wiring of this sensor confused me, as it appears that the +Vs end (white) connects to the input, but both the ground (left) and the Vout (middle) pins are connected to the box itself. I don't see how the signal can be read.
nodus:elog>w; who ; date
9:20pm up 44 day(s), 5:14, 5 users, load average: 0.29, 1.04, 1.35
User tty login@ idle JCPU PCPU what
controls pts/1 9:18pm 5 -tcsh
controls pts/2 2:37pm 6:39 25:02 25:02 /opt/rsync/bin/rsync -avW /cvs/c
controls pts/3 9:14pm w
controls pts/4 4:20pm 1:56 5:02 5:02 ssh -X rosalba
controls pts/8 8:23pm 47 4:03 -tcsh
controls pts/1 Nov 14 21:18 (pianosa.martian)
controls pts/2 Nov 14 14:37 (ldas-cit.ligo.caltech.edu)
controls pts/3 Nov 14 21:14 (rosalba)
controls pts/4 Nov 14 16:20 (192.168.113.128)
controls pts/8 Nov 14 20:23 (gwave-103.ligo.caltech.edu)
Mon Nov 14 21:20:48 PST 2011
I wrote a python script for A2L measurement.
Currently it is really primitive, but I tested the basic functionality of the script.
We already have A2L script(at /cvs/cds/rtcds/caltech/c1/scripts/A2L) that uses ezlockin, but python is more stable and easy to read.
A2L measurement method:
1. Dither a optic using software oscillator in LOCKIN and demodulate the length signal by that frequency.
2. Change coil output gains to change the pivot of the dithering and do step 1.
3. Coil output gain set that gives the smallest demodulated magnitude tells you where the current beam spot is.
Say you are dithering the optic in PIT and changing the coil gains keeping UL=UR and LL=LL.
If the coil gain set UL=UR=1.01, LL=LR=-0.99 gives you demodulated magnitude 0, that means the current beam spot is 1% upper than the center, compared to 1/2 of UL-LL length.
You do the same thing for YAW to find horizontal position of the beam.
Description of the script:
Currently, the script lives at /cvs/cds/caltech/users/yuta/scripts/A2L.py
If you run;
./A2L.py MC1 PIT
it gives you vertical position of the beam at MC1.
It changes the TO_COIL matrix gain by "DELTAGAINS", turns on the oscillator, and get X_SIN, X_COS from C1IOO_LOCKIN.
Plots DELTAGAINS vs X_SIN/X_COS and fit them by y=a+bx+cx^2.(Ideally, c=0)
Rotates (X_SIN, X_COS) vectors to get I-phase and Q-phase.
Rotation angle is given by;
which gives Q 0 slope(Ideally, Q=0).
x-intercept of DELTAGAINS vs I plot gives the beam position.
Checking the script:
1. I used the same setup when I checked LOCKIN(see elog #3857). C1:SUS-MC2_ULCOIL output goes directly to C1:IOO-LOCKIN_SIG input.
2. Set oscillator frequency to 18.13Hz, put 18.13Hz band-pass filter to C1:IOO-LOCKIN_SIG filter module, and put 1Hz low-pass filter to C1:IOO-LOCKIN_X_SIN/X_COS filter modules.
Drive frequency 18.13Hz is same as the previous script(/cvs/cds/rtcds/caltech/c1/scripts/A2L/A2L_MC2).
3. Ran the script. Checked that Q~0 and rot=-35deg.
4. Put phase shifting filter to C1:IOO-LOCKIN_SIG filter module and checked Q~0 and rotation angle.
5. Put some noise in C1:SUS-MC2_ULCOIL by adding SUSPOS feedback signal and ran the script.(Attachment #1)
During the measurement, the damping servo was off, so SUSPOS feedback signal can be treated as noise.
The result from the test measurement seems reasonable.
I think I can apply it to the real measurement, if MCL signal is not so noisy.[status: yellow]
- add calculating coherence procedure, averaging procedure to the script
- add setting checking procedure to the script
- apply it to real A2L measurement
Bay the way:
Computers in the control room is being so slow (rossa, allegra, op440m, rosalba). I don't know why.
./A2L.py MC1 PIT
ITMX was drag wiped, and the suspension was put back into place. However, after removing all of the earthquake stops we found that the suspension was hanging in a very strange way.
The optic appears to heavily pitched forward in the suspension. All of the rear face magnets are high in their OSEMs, while the SIDE OSEM appears fine. When first inspected, some of the magnets appeared to be stuck to their top OSEM plates, which was definitely causing it to pitch forward severely. After gently touching the top of the optic I could get the magnets to sit in a more reasonable position in the OSEMs. However, they still seem to be sitting a little high. All of the PDMon values are also too low:
Taking a free swing measurement now.
Nic and I discovered a problem with the in-vac wiring from the feed-thru to the top of the table. Pin 13 at the top of the stack, which is one of the coil pins on the tip-tilt quadrapus cables, is *the* shield braid on the cable that goes to the feed-thru. This effectively shorts one of our coil signals.
There are three solutions as we see it:
* swap pin 13 for something else at the top of the stack, and then swap it back somewhere else outside of the vacuum.
* swap *all* the pins at the top of the table to be the mirror. We would then need to mirror our cables on the outside, but that's less of an issue.
* make a mirror adapter that sits at the top. This would obviously need to be cleaned/baked.
None of these solutions is particularly good or fast.
We clearly need a better plan for adjusting the tip tilts in pitch, because utilizing their hysteresis is ridiculous. Koji and Steve are thinking up a set of options, but so far it seems as though all of those options should wait for our next "big" vent. So for now, we have just done alignment by poking the tip tilt.
Tomorrow, we want to open up the MC doors, open up ETMY, and look to see where the beam is on the optic. I am concerned that the hysteresis will relax over a long ( >1hour ) time scale, and we'll loose our pointing. After that, we should touch the table enough to trip the BS, PRM optics, since Koji is concerned that perhaps the tip tilt will move in an earthquake. Jamie mentioned that he had to poke the tip tilt a pretty reasonable amount to get it to change a noticeable amount at ETMY, so we suspect that an earthquake won't be a problem, but we will check anyway.
I'm very unhappy with the tip-tilts right now. The amount of hysteresis is ridiculous. I have no confidence that they will stay pointing wherever we point them. It's true I poked the top more than it would normally move, but I don't actually believe it wouldn't move in an earthquake. Given how much hysteresis we're seeing, I expect it will just drift on it's own and we'll loose good pointing again.
And as a reminder, IPPOS/ANG don't help us here before the tip-tilts are in the PRC after the IP pointing sensors.
I think we need to look seriously at possible solutions to eliminate or at least reduce the hysteresis, by either adding weight, or thinner wire, or something.
The PSL/IOO combo has not been behaving responsibly recently.
The first attachment is a 15 day trend of the MZ REFL, ISS INMON, and MC REFL power. These show two separate problems--recurring MZ flakiness, which may actually be a loose cable somewhere which makes the servo disengage. Such disengagement is not as obvious with the MZ as it is with other systems, because the MZ is relatively stable on its own. The second problem is more recent, just starting in the last few days. The MC is drifting off the fringe, either in alignment, length, or both. This is unacceptable.
The second attachment is a two-day trend of the MC REFL power. Last night I carefully put the beam on the center of the MC-WFS quads. This appears to have lessened the problem, but it has not eliminated it.
It's probably worth trying to re-measure the MCWFS system to make sure the control matrix is not degenerate.
I've noticed several CDS problems:
Since the nodus upgrade, Eric/Diego changed the old csh restart procedures to be more UNIX standard. The instructions are in the wiki.
After doing some software updates on nodus today, apache and elogd didn't come back OK. Maybe because of some race condition, elog tried to start but didn't get apache. Apache couldn't start because it found that someone was already binding the ELOGD port. So I killed ELOGD several times (because it kept trying to respawn). Once it stopped trying to come back I could restart Apache using the Wiki instructions. But the instructions didn't work for ELOGD, so I had to restart that using the usual .csh script way that we used to use.
Same thing again today. So I renamed the /etc/init/elog.conf so that it doesn't keep respawning bootlessly. Until then restart elog using the start script in /cvs/cds/caltech/elog/ as usual.
I'll let EQ debug when he gets back - probably we need to pause the elog respawn so that it waits until nodus is up for a few minutes before starting.
I've installed Monit on megatron and nodus just now, and will set it up to monitor some of our common processes. I'm hoping that it can give us a nice web view of what's running where in the Martian network.
Safety glasses were measured and they are all good. I'd like to measure your personal glass if it is not on this picture.
Safety audit went soothly. We thank all participients.
1, Bathroom water heater cable to be stress releived and connector replaced by twister lock type.
2, Floor cable bridge at the vacuum rack to be replaced. It is cracked.
3, Sprinkler head to be moved eastward 2 ft in room 101
4, Annual crane inspection is scheduled for 8am Marc 3, 2015
5, Annual safety glasses cleaning and transmission measurement will get done tomorrow morning.
Konecranes' Fred inspected and load tested all tree cranes at with 450 lbs
The crane inspection is scheduled for this coming Friday from 8-12
I wrote a small document on the application of LQG method to a Fabry-Perot cavity control.
jamie, nic, jenne, den, raji, manasa
We were doing pretty well with alignment, until I apparently fucked things up.
We were approaching the arm alignment on two fronts, looking for retro-reflection from both the ITMs and the ETMs.
Nic and Raji were looking for the reflected beam off of ETMY, at the ETMY chamber. We put an AWG sine excitation into ETMY pitch and yaw. Nic eventually found the reflected beam, and they adjusted ETMY for retro-reflection.
Meanwhile, Jenne and I adjusted ITMY to get the MICH Y arm beam retro-reflecting to BS.
Jenne and I then moved to the X arm. We adjusted BS to center on ITMX, then we moved to ETMX to center the beam there. We didn't both looking for the ETMX reflected beam. We then went back to BS and adjusted ITMX to get the MICH X arm beam retro-reflected to the BS.
At this point we were fairly confident that we had the PRC, MICH, and X and Y arm alignment ok.
We then moved on the signal recycling cavity. Having removed and reinstalled the SRC tip-tilts, and realigning everything else, they were not in the correct spot. The beam was off-center in yaw on SR3, and the SR3 reflected beam was hitting low and to the right on SR2. I went to loosen SR3 so that I could adjust it's position and yaw, and that when things went wrong.
Apparently I hit something BS table and completely lost the input pointing. I was completely perplexed until I found that the PZT2 mount looked strange. The upper adjustment screw appeared to have no range. Looking closer I realized that we somehow lost the gimble ball between the screw and the mount. Apparently I somehow hit PZT2 hard enough to separate from the mirror mount from the frame which caused the gimble ball to drop out. The gimble ball probably got lost in a table hole, so we found a similar mount from which we stole a replacement ball.
However, after putting PZT2 back together things didn't come back to the right place. We were somehow high going through PRM, so we couldn't retro-reflect from ITMY without completely clipping on the PRM/BS apertures. wtf.
Jenne looked at some trends and we saw a big jump in the BS/PRM osems. Clearly I must have hit the table/PZT2 pretty hard, enough to actually kick the table. I'm completely perplexed how I could have hit it so hard and not really realized it.
Anyway, we stopped at this point, to keep me from punching a hole in the wall. We will re-asses the situation in the morning. Hopefully the BS table will have relaxed back to it's original position by then.
Here is a two hour set of second trends of 2 sensors per mirror, for BS, PRM, ITMY and MC1. You can see about an hour ago there was a big change in the BS and PRM suspensions, but not in the ITMY and MC1 suspensions. This corresponds as best we can tell with the time that Jamie was figuring out and then fixing PZT2's mount. You can see that the table takes some time to relax back to it's original position. Also, interestingly, after we put the doors on ~10 or 20 minutes ago, things change a little bit on all tables. This is a little disconcerting, although it's not a huge change.
what's going on with those jumps on MC1? It's smaller, but noticeable, and looks like around the same time. Did the MC table jump as well?
more looking tomorrow.
But these jumps in the OSEMs are all at the level of 10-20 microns. Seems like that wouldn't be enough to account for anything; 20 microns / (pend length) ~ 50-60 microradians.
BS table and suspensions are fine.
Here's a plot of the BS, PRM, and MC1 suspension shadow sensor trends over the last 24 hours. I tried to put everything on the same Y scale:
There definitely was some shift in the BS table that is visible in the BS and PRM that seems to be settling back now. The MC1 is there for reference to show that it didn't really move.
Leo fixed an issue with the new nds2-client packages that was preventing it from retrieving online data. It's working now from matlab, python, and octave.
Here's an example of a dataviewer-like script in python:
from pylab import *
# channels are command line arguments
channels = sys.argv[1:]
conn = nds2.connection('fb', 8088)
fig = figure()
for bufs in conn.iterate(channels):
for buf in bufs:
the align script was run after the third lock here. it would have been interesting to see the arm powers in a 4th lock
Bulb went out ~10am today. Looks like the lifetime of this bulb was <100 days.
Steve: bulb is arriving next week
Bulb is replaced.
BL-FS300C-PH-LE was replaced after 2,904 hrs It did not explode this time. The 4 monts life period is actually pritty good because this is a $73. cheap bulb. The best-high priced warranty is 5 months.
PS: future option_bulbless laser projector
HITACHI LP-WU3500 PROJECTOR $2,549.00
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This would give you everything you are requesting, plus a lamp-less design and 5yr warranty. Ground shipping would be free anywhere in the lower 48, and we would not charge sales tax on orders billing/shipping outside of AZ. If you have any questions or if you would like to order... just let me know!
I noticed this behaviour since ~Dec 20th, before the power failure. The bulb itself seems to work fine, but the projector turns itself off after <1 minute after being manually turned on by the power button. AFAIK, there was no changes made to the projector/Zita. Perhaps this is some kind of in-built mechanism that is signalling that the bulb is at the end of its lifetime? It has been ~4.5 months (3240 hours) since the last bulb replacement (according to the little sticker on the back which says the last bulb replacement was on 15 Aug 2017
Light bulb replaced.
Bulb replaced at day 110 We have now spare now.
I replaced the projector bulb. Previous bulb was shattered.
The control room's north west corner smelled like propane gas yesterday around 16:30
We all agreed that the smell was real and I called the safety office. I was told that they received 6 other calls from different parts of the campus.
The smell disappeared in about a half an hour.
Property tag found.
The major changes from the previous layout:
Does any part of this layout need a radical redesign?
I realized I had overlooked an important constraint in the layout, which is that the enclosure will have two supports that occupy some region of the table - these are denoted in blue in v3 of the layout (Attachment #1). I measured the dimensions for these from the existing Y-endtable. The main subsystem this has affected is the IR transmission monitors, but I've been able to move the photodiodes a little to accommodate this constraint.
I've also done the mode-matching calculations explicitly for the proposed new layout (Attachments #2 and #3, code in Attachment #4). While the layout was largely adopted from what Andres posted in this elog, I found that some of the parameters he used in his a la mode code were probably incorrect (e.g. distance between the 750mm lens and the ETM). More critically, I think the Gouy phase for the optimized solution in the same elog is more like 60 degrees. I found that I could get a (calculated) Gouy phase difference between the two PZT mirrors of ~81 degrees by changing the green path slightly, and making the two PZT mirrors Y7 and Y8 (instead of Y7 and Y11, for which the Gouy phase difference is more like 50 degrees). But this way the two steering mirrors are much closer to each other than they were before. Other misc. remarks about the mode matching calculations:
These changes also necessitated minor changes to the transmitted IR beampath and the Oplev system, but these changes are minor. I've also switched the positions of the AUX IR power monitoring PD and the fiber coupler as suggested by Koji. The shutter has also been included.
Rana advised that we put in a lockin-output matrix which will allow us to excite any combination of MC mirrors so that we can excite pure translations or rotations of the MC beam axis. This would require us to direct a lockin output into all the three mirrors simultaneously with a +1 or -1 as needed in the matrix..
Granite base 20" x 20" x 5" locations are on the CES side of our IFO arms: as shown ETMY_ south-west, ETMX_north-east, ITMX_south-east . No height limitation. This side of the tube has no traffic.
SS cover McMaster# 41815T4 (H) SS container cov
This is my interpretation of where Steve is proposing to place the seismometers (he wrote ITMX southwest, but I'm pretty sure from the photo he means southeast).
I think his point is that these locations are on the less-used side of the beam tube, so they will not be in the way. Also, they are not underneath the tube, so we will not have any problems putting the covers on/taking them off.
I am going to tweak the alignment of the beam into the AOM (before the PMC) tomorrow morning. If anybody has any objections to this, please raise a red flag.
Proposed alignment procedure:
1. Reduce PSL power to say 10%
2. Since the AOM is not on any sort of a mechanical stage, I will have to just play around carefully until I see a maximum power rejection into first order.
I am assuming that moving the AOM is not going to affect the input pointing because all these activities are happening before the PMC. So as long as I have the output beam from the AOM aligned to the PMC at the end, everyone should be happy.
I made the following change to correct the sign of the 126MON channel:
allegra:c1aux>ezcawrite C1:PSL-126MOPA_126MON.EGUF -410
C1:PSL-126MOPA_126MON.EGUF = -410
allegra:c1aux>ezcawrite C1:PSL-126MOPA_126MON.EGUL 410
C1:PSL-126MOPA_126MON.EGUL = 410
As we learned yesterday, the PSL laser power out put mechanical shutter is not working in the remote mode. It only works in local manual mode.
Do not rely on the MEDM screen monitor readout! The position is only changing on the monitor. The main beam must be blocked before the output periscope.
Some thoughts on what happened with the MOPA cooling.
Some unknown thing happened to precipitate the initial needle valve jiggle, which unleashed a torrent of flow through the NPRO. This flow was made possible by the fact that the cooling lines are labeled confusingly, and so flow was going backwards through the needle valve, which was thus powerless to restrict it. The NPRO got extremely cold, and most of the chiller's cooling power was being used to unnecessarily cool the NPRO. So, the PA was not getting cooled enough. At this, point, reversing the flow probably would have solved everything. Instead, we turned off the chiller and thus discovered the flaky start-motor capacitor.
Now we have much more information, flow meters in the NPRO and main cooling lines, a brand-new, functioning needle valve, a better understanding of the chiller/MOPA settings necessary for operation, and the knowledge of what happens when you install a needle valve backwards.