One of the reasons that our disk is getting full is due to the scripts_archive directory. A backup script runs on op340m and makes a tar.bz2 file of the scripts directory and puts it in scripts_archive every morning at 6 AM.
On Oct 7, 2011, Koji fixed this script to point at our new scripts directory instead of the old /cvs/cds/caltech/scripts directory. Since then, however, no one has fixed the exclude file to NOT back up the junk that's in that directory. Its a 1.6 GB directory so its full of it.
I've deleted a bunch of junk from the scripts directory: this directory is for scripts, not for your personal home movies or junk data files. Put those in your USER directory. Put temporary data files in /tmp/. I've also added a few more patterns to the exclude file so that less .mpg, .png, .pdf, .dat, etc get stored every day. The new daily .tar.bz2 file wil be ~25 MB instead of 770 MB.
(also fixed the backup script to use 'env' to setup the perl environment and removed the hard-coded path to tar)
There has been a series of earthquakes since the big 7.0 in Alaska this morning.
None of the watchdogs were tripped when I came in. But I could not retrieve any info about the suspensions from fast channels because c1sus was not talking to the fb and that required an mxstream restart to fix it.
MC is trying to lock itself, but the seismic doesn't seem to get quiet. So MC is not all that happy.
I cleaned up around MC2 and 1Y1 area this morning.
ETMY NPRO moved from the side to the center of the low shelf. Thorlab catalog " as spacer " removed after lunch.
The Lightwave Controller values: LT 40.4C, LTEC +0.1V, T 41.041C, Pwr 239 mW, Adj 0, DC 1.82A, DPM 0.0V, Neon OFF, Ldon OFF, Display 5, DT 21.0C, Dtec +1.0V
B grade Nobel is awarded.
If cables could dream?
This skill should be mandatory for LIGOX graduates.
OUr disk was getting full again. Turned out my "fix" to 25 MB was only a fix to 250 MB. Since we were getting disk full warnings on our Ubuntu workstations, I deleted some COMSOL.dmg files from users/zach/ and then started deleting every other tarball from the scripts_archive directory. ~221 GB are now free. Still need to fix the exclude file for scripts better.
We locked FPMI and measured the FPMI noise (power spectrum of error signal - MICH_IN1) which will be calibrated.
The arms were locked using POX11 and POY11. The sign of MICH gain was changed to lock FPMI (from -30 to +30).
Liyuon will set up a ~5 mW He/Ne laser for waist measurement for LIGO oplev telescope.
This will be between the beam tube and the CES wall. He will do his tests in the morning.
We have tried to ssh into c1iscey yesterday morning. It just did not work. We have just tried it again (now) and it did work.
Lesson learned: always shut down the computer from a TERMINAL Do not turn it off by the manual power switch.
I was working on the electronics bench and what sounded like a huge truck rolled by outside. I didn't notice anything until now, but It looks like something became misaligned when the truck passed by (~6:45-6:50 pm). I can hear a lot of noise coming out of the control room speakers and pretty much all of the IOO plots on the wall have sharp discontinuities.
I haven't been moving around much for the past 2 hours so I don't think it was me, but I thought it was worth noting.
I broke a small bit while using the 40m drill press to vent some 1/4-20 screws for the cryo experiment.
I replaced it and refilled the small bit row in the bit index I was using; there were ~10 missing sizes
The 785 analyzer in the 40 had a wonky hard to read screen. I was hoping that a new white CRT would fix all the problems.
I installed a white CRT, which didn't fix the wonkyness, but I adjusted the CRT position, brightness, focus settings to make the screen somewhat more readable.
If we want to send the thing in for service to fix the wonkyness, we should probably hold on to the old CRT because they will probably replace the whole screen assembly and we'll lose our white screen.
Instrument rack power supplies checked and labeled at present loads.
The vacuum rack Sorensen is running HOT! Their is only 0.3A load at 24V There is plenty of space around it.
It is alarming to me because all vacuum valve positions are controlled by this 24V
40m crew and visitor Holger Muller from Berkeley.
Now netgpibdata is working again.
./netgpibdata -i 192.168.113.108 -d AG4395A -a 10 -f meas01
./netgpibdata -i 192.168.113.105 -d SR785 -a 6 -f meas01
Jenne witnessed and certified that they were working fine.
Now no one can say "it does not work"!
These weeks I was annoyed by the fact that netgpibdata was messed up by dummies.
A terrible situation was found:
1. Someone pushed the factory reset of one of the wifi bridges (LINKSYS WET54G).
2. Someone gave wrong IPs to the bridges (192.168.1.* instead of 192.168.113.*)
3. Someone left a default IP to the bridges. This means the routers had the same IPs.
I gave the IPs to the bridges. According lines of /etc/hosts in linux1 were updated.
All of the network settings are taped on the bridge now.
The reset switch of each bridge was covered by a tape so that dummies can't randomly push the button.
The command was tested with each device.
./netgpibdata -i 192.168.113.108 -d AG4395A -a 10 -f meas01
./netgpibdata -i 192.168.113.105 -d SR785 -a 6 -f meas01
Just wanted to point out that the correct "modern" path to this stuff is:
This is, of course, the same directory, but under the correct "/opt/rtcds", instead of the old, incorrect "/cvs/cds".
The lamp lasted for 4,622 hours.
This time I purchased just the bare lamp itself . The housing doubles the price. The disadvantage of this technic that the lamp housing window can not be cleaned perfectly. Atm2 picture is exaggerating this spot.
However, It does not degrade the image quality.
Dec 22 between 6AM and 7AM, physical or logical failure has occure on the 4th disk in the RAID array on linux1.
This caused the RAID disk fell into the readonly mode. All of the hosts dependent on linux1 via NFS were affected by the incident.
Today the system has been recovered. The failed filesystem was restored by copying all of the files (1.3TB total) on the RAID to a 2TB SATA disk.
The depending hosts were restarted and we recovered elog/wiki access as well as the interferometer control system.
o Recover the access to linux1
- Connect an LCD display on the host. The keyboard is already connected and on the machine.
- One can login to linux1 from one of the virtual consoles, which can be switched by Alt+1/2/3 ...etc
- The device file of the RAID is /dev/sda1
- The boot didn't go straightforward as mounting of the disks accoding to /dev/fstab doesn't go well.
- The 40m root password was used to login with the filesystem recovery mode.
- Use the following command to make the editing of /etc/fstab available
# mount -o rw, remount /
- In order to make the normal reboot successfull, the line for the RAID in /etc/fstab needed to be commented out.
o Connect the external disk on linux1
- Brought a spare 2TB SATA disk from rossa.
- Connect the disk via an USB-SATA enclosure (dev/sdd1)
- Mount the 2TB disk on /tmpdisk
- Run the following command for the duplication
# rsync -aHuv --progress /home/ /tmpdisk/ >/rsync_KA_20131229_0230.log
- Because of the slow SCSI I/F, the copy rate was limited to ~6MB/s. The copy started on 27th and finished 31st.
o Restart linux1
- It was found that linux1 couldn't boot if the USB drive is connected.
- The machine has two SATA ports. These two are used for another RAID array that is not actually used. (/oldhome)
- linux1 was pulled out from the shelf in order to remove the two SATA disks.
- The 2TB disk was installed on the SATA port0.
- Restart linux1 but didn't start as the new disk is recognized as the boot disk.
- The BIOS setting was changed so that the 80GB PATA disk is recognized as the boot disk.
- The boot process fell into the filesystem recovery mode again. /etc/fstab was modified as follows.
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
devpts /dev/pts devpts gid=5,mode=620 0 0
tmpfs /dev/shm tmpfs defaults 0 0
proc /proc proc defaults 0 0
sysfs /sys sysfs defaults 0 0
/dev/VolGroup00/LogVol01 swap swap defaults 0 0
#/dev/md0 /oldhome ext3 defaults 0 1
/dev/sda1 /home ext3 defaults 0 1
#/dev/sdb1 /tmpraid ext3 defaults 0 1
- Another reboot make the operating system launched as usual.
o What's happen to the RAID?
- Hot removal of the disk #4.
- Hot plug of the disk #4.
- Disk #4 started to get rebuilt -> ~3hours rebuilding done
- This made the system marked as "clean". Now the raid (/dev/sdb1) can be mounted as usual.
- Root password of nodus is not known.
- Connect an LCD monitor and a Sun keyboard on nodus.
- Type Stop-A. This leads the nodus transition to the monitor mode.
- Type sync.
- This leads the system rebooted.
IFO restart after the recovery of linux1
Machine recovery in the following order
- Start fb
- Start the following machines: mafalda, megatron, op340m
- Start c1ioo, c1lsc, c1sus, c1iscex, c1iscey
CDS recovery / burtrestore
- Confirm all of the RT systems are running in "green". If not, restart corresponding model.
- c1iscaux, ciscaux2 didn't have response (white boxes). Went to the LCS digital rack and power cycled these targets
- burtrestore: The snapshots at Dec 19 05:07 were used. For c1iscaux and c1iscaux2 the snapshots at Dec 22 05:07 were used.
- Reload watchdogs => restore sus damping
- MC misaligned but TEM00 was locked
- Gave a small touch on MC2 yaw => IMC almost aligned
- Autolocker wasn't running => Manually launched rather than wait for an hour for cron to launch it
- PMC was largely misaligned. => Aligned on the PSL table (PSLTRANS 0.640->0.753)
- MC WFS ON
- IFO X/Y arm locked and aligned with ASS.
- PRMI mode: manually aligned PRM. The PRMIsb momentally locked.
Well done Koji! I'm very impressed with the sysadmin skillz.
Since this configuration change, the daily backup was speeded up by factor of more than two.
It was really limited by the bandwidth of the RAID array.
rsync.backup start: 2013-12-20-05:00:00, end: 2013-12-20-07:04:28, errcode 0
rsync.backup start: 2014-01-05-05:00:00, end: 2014-01-05-05:55:04, errcode 0
(The daily backup starts from 5:00)
rsync.backup start: 2013-12-20-05:00:00, end: 2013-12-20-07:04:28, errcode 0
rsync.backup start: 2014-01-05-05:00:00, end: 2014-01-05-05:55:04, errcode 0
It seems that the most important short-term task we have right now is to figure out what our PRC length is, and what our tolerance from nominal is. Gabriele and EricQ are going to work on that tomorrow. If our PRC is of a length that we can't do anything useful for full IFO locking, we need to open up and fix it sooner rather than later.
While we're in there, we need to also put a baffle on the back side of the PRM cage, to protect the OSEMs from stray light. Den and I discovered before Christmas that turning off the OSEM and OpLev damping to the PRM (while using the POP QPD for ASC) significantly reduced the power fluctuations in the PRC. We still had arm power fluctuations, but I believe those are likely because our ALS system can't hold an arm precisely at full resonance. So, putting a black glass baffle with ~2 inch aperture right up against the OSEMs should help a lot. This week, I'll ask Steve to make me a quickie to-scale cardboard version of the baffles that he has had cut, so I can try securing it to the dirty suspension cage that we have out. I will also check to make sure I have seen with my own eyes the baffles that I need, and copper wire to tie it to the cage.
Other, lower-priority things that we should do eventually:
* Steve, please find another razor beam dump for the WFS reflections - Rana and I used one of the ones that was there for reflection off the 2 inch lens in the MC refl path (replacing the aluminum dump that has been there for ages). We also need to label all of our razor dumps with their purpose, with a label on top, so we remember not to remove dumps that are actually in use.
* At some point, we should change the one remaining steering mirror in the main PSL path that is aluminum, to a steel Polaris ("Polanski" or "Polish") mount. For now, we should just make sure we have one handy. Hopefully this will help reduce the PMC transmission drift that we see.
* Steve, in the morning sometime this week, can you please do a test of the drift of the IOO QPDs? We'd like to see a trend that is maybe 30 or 60 minutes long of the QPD signals. First 10 minutes, all lights in IFO room off. Then, 10 minutes with the lights in the PSL on. Then, the rest of the time the PSL lights off. We want to see if these are hot enough to be causing a big temperature change in the PSL box, which may then be causing some optics to drift.
* QPD code in the simulink models (trans QPDs, but also OpLevs, and anywhere else we do normalization) needs to have anti-divide-by-zero protection. I'll take care of this, it should be a quick copy of what we have elsewhere in the simulink code.
* Note to self for the future, instead of doing a dither alignment for the ASS for the arms, we can use the IP POS and IP ANG, as well as end transmission QPD signals. However, for now, the ASS is working just fine.
* We want to go back to the idea of putting a lens into the in-vac IP ANG path, to avoid the clipping that Manasa and I were seeing tonight. We want something of order 2inch diameter, 1meter focal length. The material doesn't matter, but we do want it AR coated for 1064nm on both sides. We also need to make sure that we could use a fixed 2 inch in-vac mirror mount, or something, to hold this lens. If that won't work, we need to come up with another plan. Manasa is working on thinking about precisely what lens we want to buy for a nice guoy phase telescope for IPANG, so we'll buy a lens after she puts her conclusions in the elog.
* An idea for the MC spots plot that Rana had was to plot the beam tilt and translation, rather than the raw spot positions on the mirrors. The point of this would be to make it easier to see what the output beam from the MC looks like. For MC pointing, we should also think about what our actual tolerances are. The biggest thing is that we need to get through the Faraday without being too close to any edge, and also the REFL beam needs to come back through without clipping. For now, we're just visually checking that the POP beam and the REFL beam both look unclipped since we don't have access to good camera views of either side of the Faraday.
Steve may actually be onto something with the clamps that he had made a year and a half ago. These clamps hold the glass, and then clamp to the base of the suspension cage. Not the table, but the base of the suspension cage. The drawings are in elog 6344. I'm not sure that the 1/4-20 holes in the clamp things are exactly where we'll want them, but we should be able to just dog it down to the base of the suspension. I need to check this, but it may be even easier than tieing the glass to the cage.
Also, something to think about is that the earthquake stop screws extend backwards farther than the OSEMs. I'm not sure anymore if we have shorter 1/4-20 earthquake stops around (if we do, they should be in the cleanroom shelves), but if we can't swap those out, they'll limit how close we can get to the OSEMs.
Here's an overhead photo from 6 Sept 2012:
For the IPANG telescope design, we are in the 'beyond the Rayleigh range' regime. So using a single lens to make the beam small is not a great idea. I have put down a solution where we use a pair of lenses; one of which will be mounted in-vacuum in the ETMY chamber and the other on the endtable.
This way we will also allow have some freedom to configure the layout out-of vacuum in case the need arises. The layout will look something like in the cartoon:
I also made a choice of using longer focal length lenses (CVI 2" lenses f =1 m). Below is the beam path summary for IPANG telescope. I have used the waist diameter at the ITM for propagation. The endtable is roughly at 41.2m. The QPD will be placed in front of the waist (w0=47um).
For the IPANG telescope design, we are in the 'beyond the Rayleigh range' regime. So using a single lens to make the beam small is not a great idea. I
Can you please explain this? I don't understand what exactly is the issue or 'great idea'.
I think we should be OK with just a single lens in the vacuum. But what we need is the ray tracing analysis to show what the effect will be on the IPANG readout.
Steve, please begin the vent!!
We have followed the pre-vent checklist, and done everything except check the jam nuts (which Steve can do in the morning).
We are ready to vent, so Steve, please begin bringing us up to atmosphere first thing in the morning.
Here is a copy of the list, from the wiki:
[ericq, Manasa, Jenne]
Summary: We opened up the BS and both ITM chambers today, and put the light doors on. //Edit : Manasa Post-vent the MC was very much misaligned in yaw. Both the ITMs moved in pitch as inferred from the oplev; but there is still light on the oplev PDs//. We toiled with the PMC and mode cleaner for a while to get reasonable transmission and stability (at least for a period of time). We then tried to lock IR to the y-arm, to no avail.
Locking the PMC doesn't seem very robust with the low power level we have; adjusting the gain at all when it's locked throws it right out. The mode cleaner spot was visibly moving around on MC2 as well. We'll continue tomorrow.
Details about alignment efforts: Manasa and I tried for a while to try and align the y-arm for IR. Straight out of venting the green TM00 would lock to the y-arm with about .45, as compared to .8 before venting, so it didn't seem to drift too far. The x-arm would even flash any modes, however. For a while, IR was no where to be seen after the mode cleaner. Eventually, we used the tip tilts to bring the AS beam onto the camera, which exhibited fringes, so we knew we were hitting the ITMs somewhere. We wandered around with the ETM to see if any retroflection was happening, and saw the IR beam scatter off of the earthquake stop. We moved it to the side to see it hitting the OSEM holder, and moved down to the bottom OSEM holder to get an idea of where to put pitch to get roughly the center of the ITM, then undid the yaw motion.
There, we would see very infrequent, weak flashes. We weren't able to distinguish the mode shape though; however, the flashes were coincident with where the green would lock to a very yaw-misaligned fishbone mode, to the lower right of the optic's center. We figured that if we gradually fixed the green alignment with the mode shapes we could see and actually lock on, we could use the tip tilts to adjust the IR pointing and keep it coincident and eventually resonate more. However, this didn't really work out. The flashes were very infrequent, and at this point the PMC/MC were getting very touchy, and would cease to stay locked for more than a minute or two. At this point, we stopped for the day.
After turning the slow FSS threshold down, the mode cleaner stays locked enough to do other things. We were able to align the tip tilts to the y-arm such that we were able to get some flashes in what looks like a TM00-ish mode. (It was necessary to align the PRM such that there was some extra power circulating in the PRC to be able to see the IR flashes on the ITMY face camera) This is enough to convince us that we are at least near a reasonable alignment, even though we couldn't lock to the mode.
The x-arm was in a hairier situation; since the green beam wouldn't flash into any modes, we don't even know that a good cavity axis exists. So, I used the green input PZTs to shine the green beam directly on the earthquake stops on the ITMX cage, and then inferred the PZT coordinates that would place the green beam roughly on the center of ITMX. I moved the ETMX face camera such that it points at the ETMX baffle. I tried looking for the retroreflected green spot to no avail. Hopefully tomorrow, we can get ourselves to a reasonably aligned state, so we can begin measuring the macroscopic PRC length.
Having no luck doing things remotely, we went into the ITMX chamber and roughly aligned the IR beam. Using the little sliding alignment target, we moved the BS to get the IR beam centered on ITMX, then moved ITMX to get good michelson fringes with ITMY. Using an IR card, found the retroflection and moved ETMX to make it overlap with the beam transmitted through the ITM. With the PRM flashing, X-arm cavity flashes could be seen. So, at that point, both the y-arm and x-arm were flashing low order modes.
The both arms have been locked with IR and aligned by ASS.
The IFO was left with ITMX/Y, ETMX/Y, BS, and PRM aligned, and the PSL shutter closed.
SIGNAL PATH: POY11I(+45dB)->YARM(G=+1.0)->ETMY
TRIG: TRY 0.01up/0.005down
FM TRIG: FM2/3/6/7/8/9 0.01up/0.05down, 0.5 sec delay
SIGNAL PATH: POX11I(+45dB)->XARM(G=+4.0)->ETMX
TRIG: TRX 0.01up/0.005down
FM TRIG: FM2/3/6/7/8/9 0.01up/0.05down, 0.5 sec delay
For decent locks, it was necessary that the offset of the error signals are trimmed at the input filters
even after running LSCoffset.py script.
Once the cavities were aligned for the IR, we could see the green beams are also flashing.
The Y arm was actually locked with the green with a TEM00 mode
[Rich, Jay, Koji]
We blasted the aLIGO RF PD with a 1W IR beam. We did not find any obvious damage.
Rich and Jay brought the PD back to Downs to find any deterioration of the performance with careful tests.
The power modulation setup is at the rejection side of the PBS in front of the laser source.
I checked the beams are nicely damped.
As they may come back here tomorrow, a power supply and a scope is still at the MC side of the PSL enclosure.
[EricQ, Gabriele, Manasa]
We found we had lost the Y arm pointing from yesterday. We tried to recover the pointing for a couple of hours and finally decided to take the ETMY heavy door off.
The input beam was aligned to the Y arm. We also got AS and REFL out of vacuum and on the cameras.
We put back the light doors and tried to lock the arms, but did not succeed as yet.
Things to do:
1. Lock arms for IR
2. Realign POP path
3. Recenter all oplevs
4. Try to check the state of PRC after the length change
5. Take in-vacuum pictures
[EricQ, Manasa, Koji]
We measured the spot positions on the MC mirrors and redid the MC alignment by only touching the MC mirror sliders. Now all the MC spots are <1mm away from the center.
We opened the ITMY and ETMY chambers to align the green to the arm. The green was already centered on the ITMY. We went back and forth to recenter the green on the ETMY and ITMY (This was done by moving the test masses in pitch and yaw only without touching the green pointing) until we saw green flashes in higher order modes. At this point we found the IR was also centered on the ETMY and a little low in pitch on ITMY. But we could see IR flashes on the ITMYF camera. We put back the light doors and did the rest of the alignment using the pitch and yaw sliders.
When the flashes were as high as 0.05, we started seeing small lock stretches. Playing around with the gain and tweaking the alignment, we could lock the Y arm in TEM00 for IR and also run the ASS. The green also locked to the arm in 00 mode at this point. We aligned the BS to get a good AS view on the camera. ITMX was tweaked to get good michelson.
The X arm was also aligned for the IR by hand and ASS. Also the X end green PZT was aligned to make the TEM00 mode reasonably locked.
What I did:
- Looked at the ITMXF camera. It seemed that the green beam was hitting the mirror.
- Went to the end. Looked at the X end green REFL. Tuned coarse alignment of the ETMX so that the beam was (retro-)reflected to the Faraday and the REFL PD.
- Looked at the ETMX face from the view port. Tried to locate the spot from the ITMX by shaking the ITMX alignment with 0.1 and then 0.01 increments.
- After some struggle with the ETMX and ITMX alignment, resonant fringes were found on the ETMY face while I still looked at the ETMX.
- Once the ITMX/ETMX were aligned, the BS needed to be aligned. But of course there was no IR fringe.
- Returned to the original alignment of the ITMX to find the ITMX spot on the AS camera.
Then gradually moved the ITMX to the aligned value for the green while tracking the michelson alignment with the BS.
This made the AS spots at the upper left edge of the AS video image.
- This was enough to find the IR spikes at TRX. Then the ETMX was touched to maximize the transmission.
- Lock the cavity. Use the ASS to optimize the alignement.
- Once the arm mirrors were aligned, the Xend PZT was also adjusted to have TEM00 for the green beam.
Now I leave the IFO with ITMX/Y, ETMX/Y and BS aligned. As I wrote above, the AS spot is very high at the AS camera.
We need to revisit the AS steering (SR TTs?) to ensure the AS beam unclipped.
We are close to the end of the vent except for a couple of issues.
* POP is not visible on the IR card. But we see POP flashes unclipped on the camera and also spikes in POP DC. So we are assuming that the POP path hasn't gone far off. If anybody has suggestions for a better method to check this, we could give it a try.
* PRM suspension has not been behaving well. PRM is being kicked around every 5-10 seconds when the PRC is aligned (as seen on REFL camera). We are not sure where this is coming from. The first time we saw this happening was when we were trying to lock PRC at low power even before we took the heavy doors off. So we are pretty sure this is not caused by the foil cover on the OSEMs. We tried turning ON/OFF the oplev servo, turning ON/OFF the damping loops and also checked the connections in the feedthrough and satellite box for the PRM. The OSEM sensor values for the suspension also seem to match the ones on the wiki.
GET CAMERA IMAGES OF EVERYTHING
Check all OpLevs centered, in and out of vacuum
Close PSL shutter & green shutters at the ends
This is solved.
The ASC for PRC for left turned ON. Turning it OFF solved the problem.
If there is no feedback regarding the POP alignment or anything to check with modified PRC length, we will close tomorrow morning.
This sounds great! The only suggestion that I have is for checking POP. If you have the beam on the camera, you can hold a card in front of each mirror, and find out where the edge of the beam is. Introduce the card from the side, and watch for the point where you just start to see the beam on the camera be obstructed. Repeat for the other side, and you have an idea of the centering of the beam.
I think this is most important for the in-vac mirrors, since the beam is large-ish, and we have to hit both steering mirrors at ~45 degrees.
This check was done and we had to move one of the steering mirrors in pitch. Else, everything was just fine.
In-vacuum pictures of PR2 and PR3 new positions were taken. MC spot positions measured to be < 1mm and oplevs were centered.
I checked the alignment one last time. The arms locked, PRM aligned, oplevs centered.
We went ahead and put the heavy doors ON. Steve is pumping down now!
Both arms have been aligned via ASS. PRC locked on carrier.
SB locking hasn't happened yet...
PRC Locked on Sidebands
Jenne reminded me that if we change a cavity, phases can change... So, first, I locked the PRC on the carrier, and then gave it MICH and PRCL excitations to optimize the AS55 and REFL55 phase rotation angles by looking at the excitation demodulated outputs of the unused quadrature (i.e. we want all of MICH to be in AS55 Q, so I rotated the phase until C1:CAL-SENSMAT_MICH_AS55_I_I_OUTPUT was zero on average).
This resulted in:
I then used the same settings as in ELOG 9554, except I used -1s instead of +1s for the POP110I trigger matrix elements. (I'm not sure why this is different, but I noticed that the PRC would lock on carrier with positive entries here, so I figured we wanted the peaks with opposite sign).
So far, it seems more stable than when we were doing the demodulation phase measurements, it's been locked for >15 minutes without me having to tweak the gains or the alignment from the carrier locked case.
Nice work!! As with all the other RF PDs, POP110's phase likely needs tuning. You want POP110 (and POP22) I-quadratures to be maximally positive when you're locked on sidebands, and maximally negative when locked on carrier. What you can do to get close is lock PRC on carrier, then rotate the POP phases until you get maximally negative numbers. Then, when locked on sideband, you can tweak the phases a little, if need be.
Very good news! We should have a look at the POP110 sideband peak splitting, to see if we really got the right PRC length...
Adjusted the angles as Jenne suggested:
PRCL: 100cnt -> PRM 567.01Hz
Signal in demod Q ch were minimized
REFL11I -19.2deg demod I, Lockin I out (C1:CAL-SENSMAT_PRCL_REFL11_I_I_OUTPUT) 12.6 cnt
REFL33I +130.4deg 1.70cnt
REFL55I +17.0deg 2.30cnt
REFL165I -160.5deg 27.8cnt
MICH: 1000cnt -> ITMX(-1) & (ITMY +1.015 => Minimized the signal in REFL11I to obtain pure MICH)
REFL11I +0.0 REFL11Q +0.119
REFL33I +0.023 REFL33Q -0.012
REFL55I +0.023 REFL55Q -0.113
REFL165I +0.68 REFL165Q +0.038
It seems that REFL165 has almost completely degenerated PRCL and MICH.
ITMX(-1)/ITMY(+1.015) actuation was cancelled by BS (+0.16). This introduces PRCL in REFL11I. This was cancelled by PRM (-0.084)
REFL11I +0.0 REFL11Q +0.13
REFL33I -0.012 REFL33Q 0.025
REFL55I +0.041 REFL55Q -0.45
REFL165I +0.69 REFL165Q +/-0.02
Again, It seems that REFL165 has almost completely degenerated PRCL and MICH.
[Signal source] REFL11I (-19.2deg) x 0.16, OR REFL33I (+130.4deg) x 2.0, OR REFL55I (+17.0deg) x1.0, OR REFL165I (-160.5deg) x0.05
[Trigger] POP110I(-81deg) 100/10, FM trigger 35/2, delay 0.5sec FM2/3/6/9
[Servo] FM4/5 always on. G=-0.02, Limitter ON
[Output] PRM x+1.00
[Signal source] AS55Q (-5.5deg) x 1, OR REFL11Q x 0.25, OR REFL55Q x-0.06
[Trigger] POP110I 100/10, FM trigger 35/2, delay 5sec FM2/3/9
[Servo] FM4/5 always on. G=-10, Limitter ON
[Output] ITMX -1.0 / ITMY +1.0 (or +1.015), OR PRM -0.084 / BS +0.16
The PRC (locked on carrier so far today), is pretty wobbly. It'll stay locked on carrier, but it's wobbling. The ASC was over-ridden during the vent. While I was looking around for that, I noticed that the PRM oplev sum is very low.
I went into the lab, and turned off / blocked all oplev beams except the PRM beam. I can't tell what it's clipping on, but there is definitely some red glow in the BS chamber (not as much as the stuff that's coming from the ITMY or SRM oplev hitting a tip tilt suspension - that giant spot went away when I turned off the ITMY/SRM oplev laser). The beam going into the vacuum is nice and strong, but the beam coming out is very weak, and has a horizontal line of scatter through it, like it's clipped somewhere in pitch. The PRM oplev sum is currently ~150 cts, when it should be closer to 2,000.
So far, this seems to be livable, but it's definitely disappointing.
In an effort to stop the PRC from wiggling around so much, I recentered the POP QPD after maximizing the POPDC power when locked on carrier. The beam was basically off the QPD in yaw, and at half-range in pitch.
Although the morning MC tuning looked stable, Koji pointed out that the MC_REFL_OFFSET was changed from its nominal value.
The offset was reset and this caused drift in the MC_TRANS_SUM.
To fix this:
- disabled the WFS servo
- aligned MC using MC1 and MC3
- centered beam on the MC_REFL
- reset WFS offsets
- locked MC
MC looks happy now.
ALS is in a very different state from a couple of days ago when we could successfully lock the arms and scan.
The green alignment to the arms had drifted.
PSL green alignment on the PSL table was off. The PSL green was not even on the steering mirror. Did anyone work around the PSL table in the last couple of days?
After aligning and finding the beat note, I found the ALS servo very noisy. The error signal had 10 times more rms noise than what was achieved earlier this week and there were some new 60Hz peaks as well.
Overall, we could not do any PRMI+ALS arms today
As I didn't have the green laser PZT feedback for the laser temp control, I went to the yend to check out what's the situation.
I found horrible and disgusting "remnants".
WHAT ARE THESE BSs AT THE Y END?
- The table enclosure was left open
- A (hacky) DB25 cable with clips was blocking the corridor and I was about to trip with the cable.
- This DB25 cable went to the table without going through the air tight feedthrough that is designed for this purpose.
- An SR560 (presumably for the openloop TF measurement) was left inserted in the loop with entangled cables connected to the servo box.
- Of course the laser PZT out mon was left unplugged.
Even after cleaning these cables (a bit), the end setups (including the X end too) are too amature.
Everything is so hacky. We should not allow ourselves to construct this level of setup everytime
we work on any system. This just adds more and more mysteries and eventually we can't handle
1) Fixup REFL165: remove ND filters, get box for PD, dump diode reflections, put less light on diode, change DC transimpedance (?), max power dissipation on BBPD < 0.5 W w/ 25 V bias. Perhaps replace OP27 with TLE2027.
2) Make plan for fixing fiber layout up and down the arms. Need tubing for the whole run. Don't make it cheesy. Two fibers per arm.
3) Fix LSC model to allow user switching of whitening. Get back to working on AutoLock scripts (not Guardian).
4) Manasa, Q, Jenne, tune Oplev servos Tuesday morning/afternoon.
5) Reconnect the other seismometers (Steve, Jenne). For real.
6) Balance PRMI coils at high frequency.