ID |
Date |
Author |
Type |
Category |
Subject |
4106
|
Tue Jan 4 15:12:33 2011 |
Suresh | Update | IOO | MC Trans Mon QPD gain decreased by 10 |
Decreased the gain of MC-Trans-Mon QPD ckt
The resistors R1, R2, R3, R4 are now 49.9 kOhm. The previous elog on this subject 3882 has the ckt details. |
4105
|
Tue Jan 4 13:57:48 2011 |
kiwamu | Update | IOO | incident mirror changed from 45deg to 0 deg |
I replaced the final steering mirror (Y1-1037-45-S) in the zig-zag path on the PSL table by a 0 deg mirror Y1-1037-0.
With a sensor card I confirmed the transmission reduced a lot after the replacement.
As we expected, the replacement of the mirror caused a mis-alignment of the incident beam axis to the MC, so I compensated it by touching the angle of the mirror a little bit.
After the alignment of the mirror, the MC is still resonating at TEM00.
We will check the spot positions more accurately by A2L technique.
Quote: |
- Y1-45S has 4% of transmission. Definitively we like to use Y1-0 or anything else. There must be the replaced mirror.
I think Suresh replaced it. So he must remember wher it is.
|
|
4104
|
Tue Jan 4 11:06:32 2011 |
Koji | Update | IOO | Power into Mode Cleaner increased |
- Previously MC TRANS was 9000~10000 when the alignment was good. This means that the MC TRANS PD is saturated if the full power is given.
==> Transimpedance must be changed again.
- Y1-45S has 4% of transmission. Definitively we like to use Y1-0 or anything else. There must be the replaced mirror.
I think Suresh replaced it. So he must remember wher it is.
- We must confirm the beam pointing on the MC mirrors with A2L.
- We must check the MCWFS path alignment and configuration.
- We should take the picture of the new PSL setup in order to update the photo on wiki.
Quote: |
What was the point:
I twiddled with several different things this evening to increase the power into the Mode Cleaner. The goal was to have enough power to be able to see the arm cavity flashes on the CCD cameras, since it's going to be a total pain to lock the IFO if we can't see what the mode structure looks like.
Summed-up list of what I did:
* Found the MC nicely aligned. Did not ever adjust the MC suspensions.
* Optimized MC Refl DC, using the old "DMM hooked up to DC out" method.
* Removed the temporary BS1-1064-33-1025-45S that was in the MC refl path, and replaced it with the old BS1-1064-IF-2037-C-45S that used to be there. This undoes the temporary change from elog 3878. Note however, that Yuta's elog 3892 says that the original mirror was a 1%, not 10% as the sticker indicates. The temporary mirror was in place to get enough light to MC Refl while the laser power was low, but now we don't want to fry the PD.
* Noticed that the MCWFS path is totally wrong. Someone (Yuta?) wanted to use the MCWFS as a reference, but the steering mirror in front of WFS1 was switched out, and now no beam goes to WFS2 (it's blocked by part of the mount of the new mirror). I have not yet fixed this, since I wasn't using the WFS tonight, and had other things to get done. We will need to fix this.
* Realigned the MC Refl path to optimize MC Refl again, with the new mirror.
* Replaced the last steering mirror on the PSL table before the beam goes into the chamber from a BS1-1064-33-1025-45S to a Y1-45S. I would have liked a Y1-0deg mirror, since the angle is closer to 0 than 45, but I couldn't find one. According to Mott's elog 2392 the CVI Y1-45S is pretty much equally good all the way down to 0deg, so I went with it. This undoes the change of keeping the laser power in the chambers to a nice safe ~50mW max while we were at atmosphere.
* Put the HWP in front of the laser back to 267deg, from its temporary place of 240deg. The rotation was to keep the laser power down while we were at atmosphere. I put the HWP back to the place that Kevin had determined was best in his elog 3818.
* Tried to quickly align the Xarm by touching the BS, ITMX and ETMX. I might be seeing IR flashes (I blocked the green beam on the ETMX table so I wouldn't be confused. I unblocked it before finishing for the night) on the CCD for the Xarm, but that might also be wishful thinking. There's definitely something lighting up / flashing in the ~center of ETMX on the camera, but I can't decide if it's scatter off of a part of the suspension tower, or if it's really the resonance.
What happened in the end:
The MC Trans signal on the MC Lock screen went up by almost an order of magnitude (from ~3500 to ~32,000). When the count was near ~20,000 I could barely see the spot on a card, so I'm not worried about the QPD. I do wonder, however, if we are saturating the ADC. Suresh changed the transimpedance of the MC Trans QPD a while ago (Suresh's elog 3882), and maybe that was a bad idea?
Xarm not yet locked.
Can't really see flashes on the Test Mass cameras.
|
|
4103
|
Tue Jan 4 02:58:53 2011 |
Jenne | Update | IOO | Power into Mode Cleaner increased |
What was the point:
I twiddled with several different things this evening to increase the power into the Mode Cleaner. The goal was to have enough power to be able to see the arm cavity flashes on the CCD cameras, since it's going to be a total pain to lock the IFO if we can't see what the mode structure looks like.
Summed-up list of what I did:
* Found the MC nicely aligned. Did not ever adjust the MC suspensions.
* Optimized MC Refl DC, using the old "DMM hooked up to DC out" method.
* Removed the temporary BS1-1064-33-1025-45S that was in the MC refl path, and replaced it with the old BS1-1064-IF-2037-C-45S that used to be there. This undoes the temporary change from elog 3878. Note however, that Yuta's elog 3892 says that the original mirror was a 1%, not 10% as the sticker indicates. The temporary mirror was in place to get enough light to MC Refl while the laser power was low, but now we don't want to fry the PD.
* Noticed that the MCWFS path is totally wrong. Someone (Yuta?) wanted to use the MCWFS as a reference, but the steering mirror in front of WFS1 was switched out, and now no beam goes to WFS2 (it's blocked by part of the mount of the new mirror). I have not yet fixed this, since I wasn't using the WFS tonight, and had other things to get done. We will need to fix this.
* Realigned the MC Refl path to optimize MC Refl again, with the new mirror.
* Replaced the last steering mirror on the PSL table before the beam goes into the chamber from a BS1-1064-33-1025-45S to a Y1-45S. I would have liked a Y1-0deg mirror, since the angle is closer to 0 than 45, but I couldn't find one. According to Mott's elog 2392 the CVI Y1-45S is pretty much equally good all the way down to 0deg, so I went with it. This undoes the change of keeping the laser power in the chambers to a nice safe ~50mW max while we were at atmosphere.
* Put the HWP in front of the laser back to 267deg, from its temporary place of 240deg. The rotation was to keep the laser power down while we were at atmosphere. I put the HWP back to the place that Kevin had determined was best in his elog 3818.
* Tried to quickly align the Xarm by touching the BS, ITMX and ETMX. I might be seeing IR flashes (I blocked the green beam on the ETMX table so I wouldn't be confused. I unblocked it before finishing for the night) on the CCD for the Xarm, but that might also be wishful thinking. There's definitely something lighting up / flashing in the ~center of ETMX on the camera, but I can't decide if it's scatter off of a part of the suspension tower, or if it's really the resonance. Note to self: Rana reminds me that the ITM should be misaligned while using BS to get beam on ETM, and then using ETM to get beam on ITM. Only then should I have realigned the ITM. I had the ITM aligned (just left where it had been) the whole time, so I was making my life way harder than it should have been. I'll work on it again more today (Tuesday).
What happened in the end:
The MC Trans signal on the MC Lock screen went up by almost an order of magnitude (from ~3500 to ~32,000). When the count was near ~20,000 I could barely see the spot on a card, so I'm not worried about the QPD. I do wonder, however, if we are saturating the ADC. Suresh changed the transimpedance of the MC Trans QPD a while ago (Suresh's elog 3882), and maybe that was a bad idea?
Xarm not yet locked.
Can't really see flashes on the Test Mass cameras. |
4102
|
Mon Jan 3 10:32:27 2011 |
kiwamu | Summary | elog | found hung - restarted |
Found exactly the same error messages at the end of the log file.
Quote: #4098 |
This was the error today:
GET /40m/ HTTP/1.1
Host: nodus.ligo.caltech.edu:8080
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://www.ligo.caltech.edu/~ajw/40m_upgrade.html
Cookie: elmode=threaded; __utma=65601905.411937803.1291369887.1291369887.1291369887.1; __utmz=65601905.1291369887.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); SITESERVER=ID=4981c5fd42ae53c9c9e0980f2072be4f
|
|
4101
|
Sat Jan 1 19:13:40 2011 |
rana | Update | CDS | c1pem now recording data |
I found that there was no PEM data nor any other data (no SUS or otherwise. No testpoints, no DAQ).
I went through the procedure that Jenne has detailed in the Wiki but it didn't work.
1) Firstly, the 'telnet fb 8088' step doesn't work. It says "Connected to fb.martian" but then just hangs. To replicate the effect of this step I tried ssh'ing to fb and doing a 'pkill daqd'. That works to restart the daqd process.
2) The wiki instructions had a problem. In the GUI step, it should say 'Save' after the Acquire bit has been set to 1. Even so, this works to get the .ini file right and the DTT can see the correct channel list, but none of the channels are available. There are just 'Unable to obtain measurement data'.
3) I tried running 'startc1pem', but no luck. I also tried rebooting c1sus from the command line. That worked so far as to come back up with all the right processes running, but still no data. The actual /frames directory shows that there are frames, but we just can't see the data. I also tried to get data usind the DTT-NDS2 method, but still no luck. (*** ITMX and ITMY both came back with all their filters off; worth checking if their BURTs are working correctly.)
Using DataViewer, however, I AM able to see the data (although the channel name is RED). In fact, I am able to see the trend data ever since I changed the Acquire bit to 1. Plot attached as evidence. Why does DTT not work anymore??? |
Attachment 1: Untitled.png
|
|
4100
|
Sat Jan 1 16:36:16 2011 |
rana | Configuration | SUS | rampdown.pl was not running |
The crontab for op340m which runs various IFO maintenance activities has been set to the wrong path for the watchdog rampdown script since the CDS changeover.
This is a dangerous situation. With the watchdog thresholds set as high as 1000, the magnets can be broken if the new CDS has some mental problems. This kind of thing happened before at LHO (which is why Stan invented the watchdogs). Please try to make sure that the watchdog thresholds are not set that way - its our only defense against bad CDS.
I've now corrected the crontab. The watchdog thresholds are being stepped down every 30 minutes as before.
However, out test points are gone again, so who knows how things are behaving. |
4099
|
Fri Dec 31 12:41:02 2010 |
rana | Update | General | IR flashes |
I came in today to check up on the StripTool and burn the Ubuntu LTS (new CDS OS) DVD. I was pretty excited to see the PRM flashes on Mon1.
I waggled the PRM/BS alignments and got a good contrast MICH and then bright flashes in the PRM that totally overload Mon1's CCD.
Now I can see flashes of some IR junk in the X Arm; its way off on the left edge of the mirror, but there's a beam.
For the short term, we can hook up the IO PZTs to some old EPICS channels (like one of the AUX guys in the LSC area), but eventually it has to get hooked up to the new ASC or ASS. We have to bug Joe to see where this shows up in his master diagram.
**Note: if you get lost sometimes when doing the alignments, remember that you can use time_machine_conlog.
Ex:
rossa:general>./time_machine_conlog 2010/12/31,11:00:00 PDT C1:SUS-ITMX_PIT_COMM
Issuing the conlog command:
/cvs/cds/caltech/conlog/bin/conlog +epics -interp at 2010/12/31,11:00:00 PDT "C1:SUS-ITMX_PIT_COMM"
Conlog Replied:
LIGO controls: values at 2010 12/31 11:00:00 pst
__Epics_Channel_Name______ __value_____
C1:SUS-ITMX_PIT_COMM 0.406100
Restoring now...
Restoration Successful
Attached is the last 8 days of Vacuum Pressure trend which includes the pumpdown.
|
Attachment 1: Untitled.png
|
|
4098
|
Wed Dec 29 18:53:11 2010 |
rana | Summary | elog | found hung - restarted |
This was the error today:
GET /40m/ HTTP/1.1
Host: nodus.ligo.caltech.edu:8080
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://www.ligo.caltech.edu/~ajw/40m_upgrade.html
Cookie: elmode=threaded; __utma=65601905.411937803.1291369887.1291369887.1291369887.1; __utmz=65601905.1291369887.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); SITESERVER=ID=4981c5fd42ae53c9c9e0980f2072be4f |
4097
|
Fri Dec 24 09:01:33 2010 |
josephb | Update | CDS | Borrowed ADC |
Osamu has borrowed an ADC card from the LSC IO chassis (which currently has a flaky generation 2 Host interface board). He has used it to get his temporary Dell test stand running daqd successfully as of yesterday.
This is mostly a note to myself so I remember this in the new year, assuming Osamu hasn't replaced the evidence by January 7th. |
4096
|
Thu Dec 23 22:13:50 2010 |
Koji | Update | General | PZT HV turned on |
The four IOO PZTs have been turned on in order to confirm the alignment of the IFO.
Once they are turned on, the spots (ITMX/ITMY/PRM/SRM) on the REFL CCD have been easily found.
When the X-arm was aligned to the green beam, it is easily locked to TEM00. Also some LG modes were visible.
i.e. There is some room to improve the mode matching.
The transmitted green at the PSL table is a bit too high and clipped by the first mirror on the table.
No IR flashes were found in either arms.
------------------
The below are the range and the set values of the strain gauge readback for the PZTs.
When the closed loop buttons are activated the PZTs are fixed at those values, if no one touches the set point dials.
Min Max SetP | Display on the module
PZT1 Yaw 2.20 9.95 6.08 | Broken
PZT1 Pitch -0.011 8.89 4.40 | 1.58
PZT2 Yaw 0.737 9.94 5.37 | 2.17
PZT2 Pitch 0.010 9.42 4.71 | 1.89 |
4095
|
Thu Dec 23 18:51:37 2010 |
rana | Update | Green Locking | installed doubling oven base at PSL table |
This is not such a bad base design, but remember that we have to get a couple of parts with the purple anodize to see if there is a difference between black and purple in terms of the 532 nm reflectivity. |
4094
|
Thu Dec 23 13:30:09 2010 |
steve | Configuration | VAC | slow pumpdown complete |
The pump down continued this morning by the removal of the butterfly valve. Two roughing pumps were used to reach 500 mTorr
The Maglev monitoring MEDM screen "Rotating" indicator is not working. It is on all times. Please look at Maglev controller monitor for real information.
Pump down is completed.
Configuration: vacuum normal after 86 days at atm CC1 = 1e-5 Torr
IFO is hungry for light (and maybe some goulash with a little paprikash too) |
Attachment 1: slow2dpd.jpg
|
|
4093
|
Thu Dec 23 12:19:43 2010 |
kiwamu | Update | Green Locking | installed doubling oven base at PSL table |
I gave a christmas present to a doubling oven who has been sitting on the PSL table.
The below is a picture of the present I gave. It's a base plate for the doubling oven, made from a block of aluminum, and black-anodized.
The size and the shape are nicely tailored for the combination of the Newfocus kinematic mount and the Covesion oven.
The design had been done by using Solid Works 2010

Here is a picture before he got the present.

Now he looks pretty happy.

|
4092
|
Thu Dec 23 08:54:32 2010 |
Suresh | Update | elog | the delhi univ syndrome |
Sorry folks! I couldnt get to the elog and didnt know that the elog was crashing every time I tried to access it.
But have found other means to access it and the elog is safe for now! |
4091
|
Thu Dec 23 03:15:11 2010 |
Koji | Update | elog | elogd is getting killed by Suresh |
ELOG has crashed and I restarted it.
Actually the filtering is not effective so far as elog is not using apache but has its own web server inside.
So this just block the access to port 30889 (=SVN, Dokuwiki, etc).
Quote: |
After another elog crash, I've blacklisted the domain that Suresh is using by editing the apache httpd.conf. Let's see what happens now.
|
|
4090
|
Wed Dec 22 21:38:47 2010 |
kiwamu | Configuration | VAC | Re:slow pumpdown at 12 hours |
I stopped the pumping at 9:30 pm. Now we are at 29 torr.
Quote: from #4089 |
How to stop pumping:
1, close RV1 manual valve with torque wheel
2, close V3
3, turn off roughing pumps RP1 & RP3
4, disconnect metal hose connection to butterfly valve
|
|
4089
|
Wed Dec 22 17:24:50 2010 |
steve | Configuration | VAC | slow pumpdown at 12 hours |
We have reached 200 Torr at 12 hours of slow pumping speed. Kiwamu stopped the pumping for 11 hrs last night .and I restarted it this morning.
Now RV1 is fully open with butterfly valve in place and the second roughing pump RP3 was just turned on.
How to stop pumping:
1, close RV1 manual valve with torque wheel
2, close V3
3, turn off roughing pumps RP1 & RP3
4, disconnect metal hose connection to butterfly valve |
Attachment 1: slowpd12h.jpg
|
|
4088
|
Wed Dec 22 15:47:22 2010 |
Koji | Update | VAC | Tank closing procedure |
[Jenne Kiwamu Joe Osamu Steve Koji]
Yesterday (21st), we closed the BSC and the four testmass chambers.
We splitted the team into three.
- Wiping team (Jenne/Kiwamu)
- Suspension team (Osamu/Koji)
- Door closing team (Joe/Steve)
While the wiping team was working, the suspension team prepared the next suspension.
Once the mirror was wiped, the suspension team restored that suspension at the position of the markings on the table.
After the wipe of the first mirror, the wiping team got experienced and they were the fastest among the teams.
So the wiping team worked as the second suspension team when necessary.
All of us became the closing team after the last suspension has been restored.
We checked that we still have the Michelson fringes and the oplev pointings.
In total, the work was very efficient such that we only took four hours for the entire process.
We left the suspension marking on the optical tables because they are quite useful. |
4087
|
Wed Dec 22 15:30:47 2010 |
Osamu | Update | ASC | ETMY oplev fixed |
According to c1scy.mdl, OL signals should be connected to adc_0_24 to adc_0_27 but they were connected to adc_0_16 to adc_0_19 which are assigned to QPD signals.
Actually cable connections were messed up. One ribbon cable was connected from QPD driver and ADC ports assigned for OL, and another ribbon cable was connected from the board combining the signals of oplev and QPD to ADC port assigned for QPD.
Now ETMY oplev is working well and aligned to center. |
4086
|
Wed Dec 22 11:24:23 2010 |
haixing | Update | SUS | measurement of imbalance in quadrant maglev protope |
Yesterday, a sequence of force and gain measurement was made to determine the imbalance in the
quadrant, magnetic-levitation prototype. This was the reason why it failed to achieve a stable levitation.
The configuration is shown schematically by the figure below:

Specifically, the following measurements have been made:
(1) DC force measurement among four pairs of magnets at fixed distance with current of the coils on and off
From this measurement, the DC force between pair of magnets is determined and is around 1.6 N at with a
separation of 1 cm. This measurement also lets us know the gain from voltage to force near the working point.
The force between pair "2" is about 13% stronger than other pairs which are nearly identical. The force by the
coil is around 0.017 N per Volt (levitation of 5 g per 3 Volt); therefore, we need around 12 volt DC compensation
of pair "2" in order to counterbalance such an imbalance. Given the resistence of the coil equal to 26 Om, this
requires almost 500 mA DC compensation. Koji suggested that we need a high-current buffer, instead of what
has been used now.
(2) DC force measurement among four pairs of magnets (with current of the coils off) as a function of distance
From this measurement, we can determine the stiffness of the system. In this case, the stiffness or the
effective spring constant is negative, and we need to compensate it by using a feedback control. This is
one of the most important parameters for designing the feedback control. The data is still in processing.
(3) Gain measurement of the OSEM from the displacement to voltage.
This measurement is a little bit tricky due to the difficulty to determine the displacement of the flag.
After several measurements, it gave approximately 2 V/cm.
Plan for the next few days:
From the those measurements, all the parameters for the plant and sensor that need to determine the
feedback control are known. They should be plugged into the simulink model and to see whether the
old design is appropriate or not. Concerning the experimental part, we will first try to levitate the configuration
with 2 pairs of magnets, instead of 4 pairs, as the first step, which is easier to control but still interesting.
|
4085
|
Wed Dec 22 06:50:19 2010 |
rana | Update | elog | elogd is getting killed by Suresh |
After another elog crash, I've blacklisted the domain that Suresh is using by editing the apache httpd.conf. Let's see what happens now. |
4084
|
Tue Dec 21 16:34:42 2010 |
kiwamu | Summary | VAC | All the test masses have been wiped |
[Jenne and Kiwamu]
We wiped all the test masses with isopropyl alcohol.
They became apparently much cleaner.
(how to)
At first we prepared the following stuff:
* syringe
* isopropyl alcohol
* lens papers
* cleaned scissors
Then we cut the lens papers into the half by the scissors such that the long side can remain.
This is because that the SOSs have relatively narrow spaces at their optic surfaces for putting a piece of paper.
We did vertical and horizontal wiping using the lens paper and appropriate amount of isopropyl alcohol.
Each wiping (vertical and horizontal) requires two or three times trials to appropriately remove dusts.
Amount of isopropyl:
* vertical 15 [ul]
* horizontal 10 [ul]
In addition to this, we also used the ionizer gun for blowing big dusts and fiber away from the surface.
(surface inspection)
Before wiping them, all the test masses had small dusts uniformly distributed on the HR surfaces.
Especially ETMX was quite dirty, many small spots (dusts) were found when we shined the surface with the fiber illuminator.
ETMY was not so bad, only a couple of small dusts were at around the center. ITMX/Y had several dusts, they were not as dirty as ETMX, but not cleaner than ETMY.
After we wiped them, we confirmed no obvious dusts were around the centers of the optics. They looked pretty good !
|
4083
|
Tue Dec 21 16:20:09 2010 |
steve | Configuration | VAC | pumpdown has started |
Slow pumpdown of rebuilt IFO-mark4 started at 3pm today.
We are at 680Torr at this minute with 1.5 Torr/min speed. |
4082
|
Tue Dec 21 11:52:58 2010 |
josephb | Update | Computers | RGA scripts fixed, c0rga fixed |
c0rga apparently had a full hard drive. There was 1 Gig log file in /var/log directory, called Xorg.0.log.old which I deleted which freed up about 20% of the hard drive. This let me then modify the crontab file (which previously had been complaining about no room on disk to make edits).
I updated the crontab to look at the new scripts location, updated the RGA script itself to write to the new log location, and then created a soft link in the /opt directory to /cvs/cds/rtcds on c0rga.
The RGA script should now be running again once a day. |
4081
|
Tue Dec 21 08:26:08 2010 |
rana | Update | elog | elogd is getting killed by Suresh |
Suresh killed the elogd again from India. This was the log file:
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Referer: http://www.ligo.caltech.edu/~ajw/40m_upgrade.html
Cookie: elmode=threaded; __utma=65601905.411937803.1291369887.1291369887.1291369887.1; __utmz=65601905.1291369887.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); SITESERVER=ID=4981c5fd42ae53c9c9e0980f2072be4f
Via: 1.1 sfire5.du.ac.in:3128 (squid/2.6.STABLE6)
X-Forwarded-For: 10.11.1.120
Cache-Control: max-age=259200
Connection: keep-alive
Stop killing our elog! |
4080
|
Mon Dec 20 23:32:58 2010 |
kiwamu | Update | IOO | Re:checking out & closing the vacuum chambers |
|
4079
|
Mon Dec 20 23:10:25 2010 |
Jenne | Update | SUS | Pretty much ready for pump-down. A few final things.... |
[Kiwamu, Jenne, Koji, Osamu]
We have mostly prepared the IFO for pump down.
After lunch [Steve, Bob, Koji, Kiwamu, Jenne, Joe, Joon Ho, Vladimir, Osamu] put the access connector back in place. Hooray! Steve still has to check the Jam Nuts before we pump down. Kiwamu checked the leveling of the IOO table, and fixed all of the weights to the table.
For all 4 test masses, bars (upside-down dog clamps) were placed to mark the alignment of 2 sides of the suspension tower. All test mass tables were re-leveled, and the weights fixed to the tables.
For ETMY, PRM, BS, SRM, we confirmed that the OSEMs were close to their half-range. ETMX was already fine. ITMY (the screens and the optics wiki are still old-convention, so this is listed as ITMX! No good!) OSEMs are pretty much fine, but ITMX desperately needs to be adjusted. Unfortunately, no one can find the standard screwdriver (looks like a minus), to adjust the ITM OSEMs. All the other towers had hex-key set screws, but the ITMs need a screwdriver. We will ask Bob to sonicate a screwdriver in the morning.
|
4078
|
Mon Dec 20 22:56:20 2010 |
Jenne | Update | IOO | Plan for closing the vacuum chambers |
Tuesday
- If still everythig is fine, put the BS heavy door.
- Do the following list for all of the testmass chambers.
- Check if the OSEMs and the OPLEV are still fine. (ITMX and ITMY were not done on Monday, so need extra care.)
- Inspect the surface of the mirror with a laser pointer or a fiber coupled halogen light.
- Blow the mirrors by the ionization gun.
- Inspect the mirror surface again.
- Move the suspension tower close to the door.
- Make a single drag-wipe with iso
- Move the SOS tower at the original place.
- Check the OSEMs and the OPLEVs. Adjust the alignment.
- Put the heavy door.
- Start slow pumping |
4077
|
Mon Dec 20 16:57:58 2010 |
steve | Update | IOO | checking out & closing the vacuum chambers |
- Check EQ-stops
- clamp down counter weights
- check other components are clamped
- remove all tools
- check cabling is not is not shorting out seismic stack or blocking beam
- confirm well centered spots on mirrors
|
4076
|
Mon Dec 20 10:47:29 2010 |
Koji | Update | IOO | Plan for closing the vacuum chambers |
Monday
- Place the bars on the in-vac tables to mark the positions of the test mass suspensions. (ITMX/ITMY/ETMX/ETMY)
- Check the table leveling again (ITMX/ITMY/ETMX/ETMY/BSC)
- Align the whole interferometer.
- Check the OPLEV spots by either QPDs or apertures
- Check the OSEM values (MC1/2/3, BS, PRM, SRM, ITMX, ITMY, ETMX, ETMY)
- Energize OMC PZTs.
- We have removed the cards at the back of the HV driver.
- Insert the card and check the connection.
- Adjust the DC values at the middle of the range.
-> They have an internal bias circuit to provide +75V at the outputs. (D060287).
The actual voltages confirmed.
- Adjust the physical knobs of the PZTs such that we can see the spots at the OMCR cam
- If everything is fine, attach the access connector.
- If still everythig is fine, put the BS heavy door.
Tuesday
- Do the following list for all of the testmass chambers.
- Check if the OSEMs and the OPLEV are still fine.
- Inspect the surface of the mirror with a laser pointer or a fiber coupled halogen light.
- Blow the mirrors by the ionization gun.
- Inspect the mirror surface again.
- Move the suspension tower close to the door.
- Make a single drag-wipe with iso
- Move the SOS tower at the original place.
- Check the OSEMs and the OPLEVs. Adjust the alignment.
- Put the heavy door.
- Start slow pumping |
4075
|
Mon Dec 20 10:06:36 2010 |
kiwamu | Update | CDS | ETMY damped |
Last Saturday I succeeded in damping the ETMY suspension eventually. 
This means now ALL the suspensions are happily damped.
It looked like some combination of gains and control filters had made unstabie conditions.

I actually was playing with the on/off switches of the control filters and the gain values just for fun.
Then finally I found it worked when the chebyshev filters were off. This is the same situation as Yuta told me about two months before.
Other things like the input and the output matrix looked nothing is wrong, except for the sign flips at ULSEN and SDSEN as I mentioned in the last entry (see here).
So we still should take a look at the analog filters in order to make sure why the signs are flipped. |
4074
|
Sun Dec 19 22:45:28 2010 |
rana | Update | elog | restarted |
I deleted the yellow box which showed up by default when making an elog entry. Would be nice if we could make it so that you have to click a button to 'opt-in' for the yellow box rather than get it by default.
I added a 'robots.txt' file to the /users/public_html/ area using Google's instructions (it only works with robot compliant crawlers), but am not sure how to put robots.txt into the elog port. |
4073
|
Sun Dec 19 11:19:42 2010 |
Koji | Update | elog | restarted |
Did it again. It seemed that Google bot came to the elog and tried to obtain "http://nodus.ligo.caltech.edu:8080/robots.txt". That was the last of the log.
Bot came from the AJW's homepage. Also Google FeedFecther came to the elog. |
4072
|
Sat Dec 18 23:33:06 2010 |
Koji | Update | elog | restarted |
Did the same.
Quote: |
The process was taking up 100% of the CPU and not responding via web. The .log file showed the last action was somebody reading/editing one of Jenne's entries from August regarding TT ECD. The restart script didn't work, so I had to do a 'kill -9' to get it to die.
|
|
4071
|
Sat Dec 18 06:24:49 2010 |
rana | Update | elog | restarted |
The process was taking up 100% of the CPU and not responding via web. The .log file showed the last action was somebody reading/editing one of Jenne's entries from August regarding TT ECD. The restart script didn't work, so I had to do a 'kill -9' to get it to die. |
4070
|
Sat Dec 18 01:17:04 2010 |
kiwamu | Update | IOO | some more alignments |
[Koji and Kiwamu]
We did some more vacuum works today. It is getting ready to pump down.
(what we did)
- alignment of the POY mirrors. Now the beam is coming out from the ITMY chamber successfully
- leveling of the tables (except for the IOO and OMC chamber)
- realigned the beam axis down to the Y arm because the leveling of the BS table changed the alignments.
- installed IP_POS mirrors
- aligned the green beam and made it overlap with IR beam path.
- repositioned green steering mirrors since one of them are too close to the dark beam path
- aligned everything.
|
4069
|
Fri Dec 17 03:37:47 2010 |
rana | Update | SUS | ITMY / SRM / BS / PRM OPLEVs aligned |
Quote: |
The sole thing that has been deviated from the optical layout was that the SRM returning beam had to be reroute
as the SRM has better reflectivity on the AR surface in stead of the HR one.
|
I suppose that if we were really clever we would intentionally choose either the AR or HR surface so as to minimize the effect of the thermal lensing and/or thermal expansion from the locked interferometer absorption. |
4068
|
Fri Dec 17 02:22:06 2010 |
kiwamu | Update | CDS | ETMY damping: not good |
I made some efforts in order to damp ETMY, however it still doesn't happily work.
It looks like something wrong is going on around the whitening filters and the AA filter borad.
I will briefly check those analog parts tomorrow morning.
- - -(symptom)
Signs of the UL and the SD readouts are flipped, which I don't know why.
At the testpoints on the analog PD interface board, all the signs are the same. This is good.
But after the signals go through the whitening filters and AA filters, UL and SD become sign-flipped.
I tried compensating the sign-flips by changing the sign by means of the software, but it didn't help the damping.
In fact the suspension got crazy when I activated the damping. So I have no idea if we are looking at exactly right readouts or some sort of different signals.
- - -(fixing DAC connector)
I fixed a connector of the DAC ribbon cable since the solderless connector was loosely locked to its cable.
Before fixing this connector I couldn't apply voltages on some of the coils but now it is working well.
|
4067
|
Fri Dec 17 00:55:30 2010 |
Koji | Update | IOO | The dark port beams reached the AP table |
[Koji and Kiwamu]
We obtained two dark port beams on the AP table: OMC REFL and AS
- First, IPANG and BS were aligned so as to have the beams on the center of the ETMs.
- Then ITMX/ITMY/PRM/SRM were aligned to have fringes in a single spot anywhere.
- As we already had the dark port beam on the steering mirrors on the BS table, today the PZT mirrors were adjusted.
This work was the beam steering between the BS table to the OMC table. After some tweaking of the mirror mounts,
the spot on the last PZT mirror was found.
As we have not touched any of the OMC optics since they were aligned well, the alignment has been adjusted by the nobs of the PZT steering mirrors.
Once the beam is on the output mode matching telescope (OMMT), the work was quite easy thanks to the beam shrinking by the OMMT.
Note that the dark port beam is slightly clipped by the green steering mirror. The steering mirror will be moved next time.
After the alignment, we indeed obtained OMC REFL and AS beams on the AP table.
The fringes were visible on the OMC REFL CCD.
We keep the dark port setup on the OMC (in-vac) and AP tables so that they can be the reference of the dark port alignment.
In principle we can align the beams onto the OMC by the two PZT mirrors.
What is left?
Our minimum success of this vent is to setup the X arm cavity which is needed for the green locking.
This setup was already realized. So we fulfilled the condition to close the tank even if the damping of
the ETMY is not achieved. (But we should try)
Tomorrow, we make a light touches to POY, Green, IPPOS, and check the table leveling, clamping, etc, in general.
JD: We should check OSEMs for all optics *after* table leveling. Some of them (esp. BS and ITMX) are currently close to their limits right now.
KA: Check green alignment. / Take photos of the tables. / Fix the leveling weights
Location Optics Action
--------------------------------------------------------------
@ITMY - POY mirror replacement (45deg->0deg) / alignment
@BSC - Green steering alignment
IPPOS steering alignment
Beam dumps
Table Leveling
@ETMX - Al foil removal
Table Leveling
@ETMY - ETMY damping
OSEM
OPLEV
Table Leveling
@ITM/ETM - Mirror Wiping
|
4066
|
Fri Dec 17 00:30:05 2010 |
Koji | Update | IOO | ITMY / SRM / BS / PRM OPLEVs aligned |
[Steve and Koji]
The invac OPLEV mirrros were aligned before we get to the PMA party.
The OPLEV mirrors were adjusted in accordance with the optical layout.
Surprisingly the optical layout was enough precise such that we have the healthy red beams on the optical tables.
Steve placed the apertures at the position of the returning spots while I shook the stack to check if the range of the spot motion is sufficient.
The sole thing that has been deviated from the optical layout was that the SRM returning beam had to be reroute
as the SRM has better reflectivity on the AR surface in stead of the HR one. |
4065
|
Thu Dec 16 15:10:18 2010 |
josephb, kiwamu | Update | CDS | ETMY working at the expense of ETMX |
I acquired a second full pair of Host interface board cards (one for the computer and one for the chassis) from Rolf (again, 2nd generation - the bad kind).
However, they exhibited the same symptoms as the first one that I was given.
Rolf gave a few more suggestions on getting it to work. Pull the power plugs. If its got slow flashing green lights, just soft cycle, don't power cycle. Alex suggested turning the IO chassis on before the computer.
None of it seemed to help in getting the computer talking to the IO chassis.
I finally decided to simply take the ETMX IO chassis and place it at the Y end. So for the moment, ETMY is working, while ETMX is temporarily out of commission.
We also made the necessary cables (2x 37 d-sub female to 40 pin female and 40 pin female to 40 pin female) . Kiwamu also did nice work on creating a DAC adapter box, since Jay had given me a spare board, but nothing to put it in. |
4064
|
Thu Dec 16 10:52:42 2010 |
josephb | Update | Cameras | New PoE digital cameras |
We have two new Basler acA640-100gm cameras. These are power over ethernet (PoE) and very tiny. |
Attachment 1: basler.jpg
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4063
|
Thu Dec 16 01:23:43 2010 |
kiwamu | Update | SUS | SRM OSEMs installed |
[Zach and Kiwamu]
We worked on some more vacuum businesses. Today we finished did the following works:
- alignment of the POX mirrors
- alignment of the POP1 and POP2 mirrors
- installation of OSEMs onto SRM
- alignment of the SRM tower
(alignment of POP mirrors)
Since a beam on the POP path was quite too weak to see even by IR viewers, we used a He-Ne laser to imitate the real beam instead.
We injected the He-Ne beam from an optical bench to the chamber, and made it go through the PRM and PR2 by using some steering mirrors.
(OSEM cables)
The pin assignment was flipped in a way of mirror image due to the extension cables which cause a mirroring.
So we made mirroring connectors to flipp them back to the correct pin assignment, and plugged the mirroring connectors in between the feedthrough of the BS chamber and the SRM satellite box.
This is a picture showing how they are connected now.

|
4062
|
Wed Dec 15 23:10:40 2010 |
Koji | Update | IOO | SRM Oplev / Dark Steering mirrors installed |
I helped the vacuum installation work in the evening.
- Three steering mirrors after the SRM (OM1-OM3) were installed on the table. OM1 and OM2 were aligned.
OM3 is in-place but not aligned to the OM4 (PZT).
- The ITMY oplev setup was disintegrated. The SRM/ITMY oplev beams were prepared.
- The SRM oplev mirrors were placed on the table and aligned.
- The ITMY oplev mirrors were placed on the table but not in-place. |
4061
|
Wed Dec 15 18:29:59 2010 |
Jenne | Update | PEM | Seismometer Channels Being Recorded Again |
The Seismometer channels are once more being recorded. Alastair brought Gur1 back from the ATF the other day, and today I put it in its place below MC2 (yeah, the numbers are backwards. But they always have been.)
I checked the matching between BNC inputs on the breakout box to the ADC channels as labeled in the SimuLink diagram. To do this I had all 32 channels activated, and I put a 1Hz, 1Vpp sine wave into various BNC inputs to see what channel they showed up as. At first things were a bit backwards (BNC channels 1-16 going to ADCs 16-31, and BNCs 17-32 going to ADCs 0-15), but then Joe quickly flipped the cables on the adapter board in the back and things are in the correct order now. Channel 1 on the BNC board corresponds to channel 0 on the ADC, etc.
I checked that jumping near each seismometer made the signals spike, which they did.
I then changed the channel names in the c1pem.mdl SimuLink diagram to match the old channel names for the Guralps and the accelerometers, and deleted all of the other channels that aren't being used. There's a table in the diagram to indicate what goes with what, as of today. If you do anything to the PEM diagram, please update the table so it's easy to look things up.
I recompiled the code, but have not yet restarted the frame builder since Zach and Kiwamu are working on some things in the chamber, and I don't want to be annoying (so the channels aren't actually being recorded quite yet).
Edit, 7:15pm: Just kidding. Something didn't work, and I have to track down what. I'm not getting any data yet. |
4060
|
Wed Dec 15 17:21:20 2010 |
josephb | Update | CDS | ETMY controls status |
Status:
The c1iscey was converted over to be a diskless Gentoo machine like the other front ends, following the instructions found here. Its front end model, c1scy was copied and approriately changed from the c1scx model, along with the filter banks. A new IOP c1x05 was created and assigned to c1iscey.
The c1iscey IO chassis had the small 4 PCI slot board removed and a large 17 PCI slot board put in. It was repopulated with an ADC/DAC/BO and RFM card. The host interface board from Rolf was also put in.
On start up, the IOP process did not see or recognize any of the cards in the IO chassis.
Four reboots later, the IOP code had seen the ADC/DAC/BO/RFM card once. And on that reboot, there was a time out on the ADC which caused the IOP code to exit.
In addition to the not seeing the PCI cards most of the time, several cables still need to be put together for plugging into the the adapter boards and a box need to be made for the DAC adapter electronics.
|
4059
|
Wed Dec 15 16:04:49 2010 |
steve | Configuration | VAC | vacuum valves found in default condition |
This condition is created when we run out of nitrogen that holds the valves in set positions. The Maglev and other turbos are still running in this configuration so one has to pay attention that the foreline valves are open.
Reset error message on vacuum screen and opened V4 & V5 at 3pm today. |
4058
|
Wed Dec 15 14:23:32 2010 |
Koji | Update | CDS | ETMY IO chassis update |
Great!
I wish this board works fine at least for several days...
Quote: |
I gave Alex a sob story over lunch about having to go and try to resurrect dead VME crates. He and Rolf then took pity on me and handed me their last host interface board from their test stand, although I was warned by Rolf that this one (the latest generation board from One Stop) seems to be flakier than previous versions, and may require reboots if it starts in a bad state.
Anyways, with this in hand I'm hoping to get c1iscey damping by tomorrow at the latest.
|
|
4057
|
Wed Dec 15 13:36:44 2010 |
josephb | Update | CDS | ETMY IO chassis update |
I gave Alex a sob story over lunch about having to go and try to resurrect dead VME crates. He and Rolf then took pity on me and handed me their last host interface board from their test stand, although I was warned by Rolf that this one (the latest generation board from One Stop) seems to be flakier than previous versions, and may require reboots if it starts in a bad state.
Anyways, with this in hand I'm hoping to get c1iscey damping by tomorrow at the latest. |