ID |
Date |
Author |
Type |
Category |
Subject |
2538
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Thu Jan 21 11:08:30 2010 |
kiwamu, steve | Update | VAC | Dry Pump replacement |
This morning I and Steve replaced the dry fore pump of TP3, which is located under the y-arm.
After replacing it we confirmed vacuum normal condition. The fore line pressure of TP3 went down to 11 mTorr from 750 mTorr
Attached picture is new pump after setup. |
Attachment 1: DSCN0428.JPG
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5261
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Thu Aug 18 10:17:04 2011 |
kiwamu, steve | Update | SUS | oplevs reestablished at Vertex |
Kiwamu and Steve, from yesterday
PRM and BS oplev paths were relaid after setting 1/2 OSEM voltages. The incident beam on suspended optics are centered within ~ +- 2 mm
I noticed many unvected ss screws are used on the big Al table tops. The SS 1/4-20 screws
used on the optical tables in vacuum MUST be VENTED!
Also, please use SS clamps. Replace aluminum ones when you can. We have plenty baked ones.
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2676
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Tue Mar 16 05:10:39 2010 |
koji | Update | Environment | Earthquake, Mag 4.4 |
Some of the suspensions got watchdog tripped -> enabled -> damped.
The MC mirrors got slightly misaligned.
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Attachment 1: 100316_MC_SUS.png
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2894
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Fri May 7 11:21:49 2010 |
koji | Update | 40m Upgrading | New improved design for the 11MHz photodiode |
How much is the width?
Quote: |
This should be better. It should also have larger resonance width.
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3577
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Wed Sep 15 16:00:26 2010 |
koji, steve | Update | MOPA | |
We removed the Lightwave MOPA Controller from 1X1 (south) It was a real painfully messy job to pull out the umbilical.
Note: the umbilical is shading it plastic cover. It is functional but it has to be taken out side and cleaned. Do not remove it from it's plastic bag in a clean environment.
Now Joe has room for IOO chassy in this rack.
We also removed the Minco temp controller and ref. cavity ion pump power supply.
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3578
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Wed Sep 15 16:12:35 2010 |
koji, steve | Update | MOPA | MOPA Controller is taken out of the PSL rack |
We removed the Lightwave MOPA Controller, PA#102, NPRO206 power supply to make room for the IOO chassy at 1X1 (south) rack.
The umbilical cord was a real pain to take out. It is shading its plastic cover. The unused Minco was disconnected and removed.
The ref. cavity ion pump controller- power supply was temporarily taken out also. |
Attachment 1: P1060843.JPG
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3604
|
Fri Sep 24 00:56:35 2010 |
koji, tara | Update | Electronics | testing TTFSS |
We found that a transistor was broken from yesterday spark too. We partially fixed TTFSS, and it should be enough for testing purpose.
From yesterday test, we found that the RF amplifier for LO signal was broken. There was no spare at the electronic shop at Downs,
so we shorted the circuit for now. Another part which was broken too was a transistor, Q3 PZT2222A, on D0901846.
It was removed and two connections, which are for Q3's 1 and 3 legs, are shorted. Now the voltages out from the regulators are back to normal.
We are checking a MAX333A switch, U6A on D0901894. it seems that the voltage that controls the switch disappears.
There might be a bad connection somewhere. This will be investigated next. |
3607
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Fri Sep 24 23:47:10 2010 |
koji, tara | Update | Electronics | testing TTFSS |
Q3, a PZT2222A transistor, on D0901846 is replaced by a GE-82. However, the board is still not fully function.
Since Q3, PZT2222A, was broken, I went to Wilson house and got some SP3904's for replacement. But somehow, I broke it during
installation, and did not notice it, and resumed the test. When I got to test 8 on the list, the TTFSS did not work as specified.
Koji checked and found out that -15V, Nref, Vref voltages output did not work correctly. So the SP3904 I installed was removed
and replaced with another SP3904 by Koji, and Vref is working.
Q4 transistor is broken as well and it was replaced by GE 82.
Q1 might be broken too since -15V out is not working.
I'll go to Wilson house to get more transistors next week.
After the broken parts have been replaced, I have to make sure that I separate the power supply board from the rest of the circuit and
check if all V outputs are working, then reconnect the board and check if the current input is reasonable before resume the test.
I hope the wrong input voltage problem today wouldn't damage anything else.
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3617
|
Tue Sep 28 21:11:52 2010 |
koji, tara | Update | Electronics | Fixing the new TTFSS |
We found a small PCB defect which is an excess copper shorting circuit on the daughter board,
it was removed and the signal on mixer monitor path is working properly.
We were checking the new TTFSS upto test 10a on the instruction, E1000405 -V1. There was no signal at MIXER mon channel.
It turned out that U3 OpAmp on the daughter board, D040424, was not working because the circuit path for leg 15 was shorted
because of the board's defect. We can see from fig1 that the contact for the OpAmp's leg (2nd from left) touches ground.
We used a knife to scrap it out, see fig 2, and now this part is working properly.
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Attachment 1: before.jpg
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Attachment 2: after.jpg
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Attachment 3: before.jpg
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Attachment 4: after.jpg
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4777
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Wed Jun 1 13:33:22 2011 |
koji, tara | Update | Electronics | TTFSS #7 |
We replaced GE81 by PZT2907A (PNP transistor) in TTFSS #7, it's working fine.
Last time I broke Q4 transistor, which is used in the low noise power module for TTFSS, (see the schematic) and could not find another PZT2907A, so GE81 was used temporarily. Now we changed it back to PZT2907A as designed. I tested it by checking the voltage outputs of the board. It works fine, all voltage outputs are correct. I labeled one of the slot on the blue cabinet tower and kept the rest of the transistors there.

Quote: |
I brought TTFSS set #7 to 40m and kept it in the electronic cabinet.
note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82.
Q3 is now pzt3904, not PZT2222A.
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3596
|
Thu Sep 23 02:23:04 2010 |
koji,tara | Summary | Electronics | Testing new TTFSS |
I tested the new table top frequency stabilization system(TTFSS),
I haven’t finished it yet, and accidentally fried one amplifier in the circuit.
We received three sets of a new TTFSS system which will replace the current FSS.
It needs to be checked that the system works as specified before we can use it.
- Result
I followed the instruction written on E10000405-v1
The first test inspected how much the currents were drawn from the +/- 24 V power supply.
+24 V drew 350 mA and -24 V drew 160 mA as shown on pwr supply’s current monitor.
They exceeded the specified value which was 200 +/- 20 mA, but nothing went wrong during the test.
Nothing got overheated, all voltage outputs were correct so I proceeded.
I have gone down the list to 6, and everything works as specified.
- Correcting the document for the test procedure
I found a few errors on the instruction document. I’ll notify the author tomorrow.
- How GVA-81 amplifier on D0901894 rev A got fried
During the test, I used a mirror on a stick that looked like a dental tool to see under the board.
Unfortunately, the steel edge touched a board and caused a spark. The voltage on -24 dropped to -16.
I think this happened because the pwr supply tried to decrease the current from shorted circuit,
as I shorted it only short time ( a blink of an eye), it could not reduce the voltage to zero.
When I was checking the power supply and about to adjust the voltage back to the right value
(about 4-5 seconds after the spark,) smoke came out of the circuit.
Koji investigated the circuit and found that a GVA 81 amplifier was broken.
This was checked by applying 5V to the amp, and slightly increasing the current.
The voltage dropped to zero as the amp was broken, so its circuit was shorted.
I’ll see if I can replace this at EE lab at Downs.
If I cannot find a spare one, I’ll replace it with a resistor and resume the test procedure.
Because it amplifies LO signal, which won’t be used during the test.
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7952
|
Tue Jan 29 10:59:37 2013 |
lazy person | Frogs | General | better plan |
I propose we work around this problem with giant flip-flops. These are in the vein of the take-off-your-shoes-and-put-on-Crocs, without the taking off your shoes part. They're a little annoying on the sticky mats, but otherwise great. They are also super easy to put on and take off without hands, so there's no excuse for wearing them around the control room.
I propose we buy many pairs of the smalls in green (since we already have one green small...they are big on me, so should be just right for most people), and a few mediums in, say, blue, and a few larges in black, and then maybe a few extra larges in green for people with extraordinarily large feet (they only have 3 colors). Then we can keep a few pairs of each by each door to the lab, and have no more tracking dirty control room filth into the lab. |
4752
|
Fri May 20 01:02:50 2011 |
loose connection hunter | Update | SUS | loose connection on ETMY rack |
The UL signal of the shadow sensor on ETMY went to zero this evening.
This was due to a loose connection on the cross connection board on the 1Y4 rack.
In order to make them tighten, a combination of stand-offs and screws were installed on the connectors. They won't be loose any more.

|
3701
|
Tue Oct 12 23:35:12 2010 |
mafalda | Update | Computers | celan-installed CentOS 5.5 on mafalda |
Quote: |
I clean-installed CentOS 5.5(32bit) on mafalda.
No firewalls, no SELinix.
|
Yuta has removed my ethernet connection . Help me!!!
rossa:mDV>ping mafalda
PING mafalda.martian (192.168.113.23) 56(84) bytes of data.
From rossa.martian (192.168.113.215) icmp_seq=2 Destination Host Unreachable
From rossa.martian (192.168.113.215) icmp_seq=3 Destination Host Unreachable
From rossa.martian (192.168.113.215) icmp_seq=4 Destination Host Unreachable
--- mafalda.martian ping statistics ---
5 packets transmitted, 0 received, +3 errors, 100% packet loss, time 3999ms
, pipe 3 |
8769
|
Thu Jun 27 17:49:17 2013 |
manasa | Update | Green Locking | c1als model edited |
Quote: |
Could be that this is OK, but it doesn't yet make sense to me. Can you please explain in words how this manages to apply the calibration rather than just add an extra gain to the phase tracking loop?
|
The calibration is applied by adding an extra gain. But, I missed the point that I should be doing this outside the phase-tracking loop....my BAD .
So I modified the model such that the calibration is done without disturbing the phase tracking loop.
Right now, epics input 'PHASE_OUT_CALIB' accepts the calibration and we get the calibrated phase tracker output converted from deg to Hz at 'PHASE_OUT_HZ'. I have also made it a DAQ channel to be used with dataviewer and dtt.
medm screens have been modified to accommodate these additions to the phase tracker screen. I used Yuta's phase tracker calibration data in elog to set PHASE_OUT_CALIB in the medm screens.


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8772
|
Thu Jun 27 19:17:03 2013 |
manasa | Update | LSC | Xarm ALS out-of-loop noise |
Measured frequency noise is ~10Hz/rtHz @100Hz.
Measure the out-of-loop noise of Xarm ALS:
1. The X-arm was locked for IR using PDH error signal.
2. 'CLEAR HISTORY' of the phase tracker filters.
3. Measured the power spectrum of the phase tracker output. I have used the newly created calibrated channel "PHASE_OUT_DQ. So the phase tracker output now reads in Hz.
Discussion:
The measurement was done with beat note frequency at ~40MHz. The flat noise level of 10Hz/rtHz from 20-100Hz (in plot 2) is not good. We should investigate as to what sets this noise level. The spike at 60Hz is because the 60Hz frequency comb filter was not enabled.
I plan to the following to get a clearer outlook
1. Connecting the beat box to an RF source and measure the noise levels for a range of frequency inputs to the beatbox.
2. Measure the noise at C1:ALS-BEATX_FINE_I_IN1 (before the antiwhitening filters) and check whether the new whitening filters has done anything good with respect to minimizing the DAQ noise.
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Attachment 1: ALS_OoL.pdf
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Attachment 2: ALS_OoL1.pdf
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8779
|
Fri Jun 28 02:12:21 2013 |
manasa | Update | LSC | PRMI + X arm ALS |
X arm stabilized using ALS while PRMI stayed locked
[Rana, Lisa, Jenne, Manasa]
Attachment 1
Time series : ALS enabled at t = 0 and disabled at t = 95s

What we did:
1. Jenne will elog about ASC (POP QPD) updates.
2. Found the beat note between Xarm green and PSL green.
3. Stabilized arm fluctuation by enabling ALS servo.
4. Scanned the arm for carrier resonance by ramping on the offset and set the offset such that we had IR resonating (TRX fluctuated between 0.1 and 0.8 counts).
5. Disabled the ALS servo and locked PRMI using AS55 for MICH and REFL33 for PRCL.
6. Enabled ALS.
Discussion:
Enabling ALS to detune the arm out of resonance kept PRMI locked (currently for a span of few tens of seconds). However we could not see PRMI locked as stably compared to when the arms are misaligned. Everytime the offset was set IR to resonate, the PRMI was kicked out of lock.
Also there is some leakage at the arm transmission when PRMI was locked. The leakage was visible at ETMX transmission as flashes in different higher order modes indicating the not-so sufficient ALS stability. The leakage sets an offset at TRX measuring 0.01-0.05 counts.
To do list:
The ALS_OFFSETTER1 has to be calibrated in FSR. We were giving random offsets to do the offset scan.
Misc:
Installed a filter before ETMXT camera to remove the refl green. (Note to myself: The filter needs to go on a better mount/adapter). |
8794
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Wed Jul 3 10:39:25 2013 |
manasa | Update | IOO | MC aligned and WFS enabled |
I found WFS had been left disabled from sometime yesterday. I don't see anyone mentioning when and why they had turned OFF the WFS servo.
I aligned MC and turned ON the WFS servo. MC is back. |
8807
|
Mon Jul 8 21:46:31 2013 |
manasa | Update | Green Locking | Beatbox |
[Koji, Manasa]
I wanted to investigate on the ALS electronics(in particular the beatbox and the phase tracker) and find out if the beatbox is showing a linear behavior
as we expect it to and as to why we have been seeing sudden jumps at the phase tracker output.
I have been using the Xarm part of the beabox.
I used Marconi as well as signal generator to do frequency sweep/modulation at the RF input of the beatbox and looked at the I_MON output of the beatbox.
We observed sudden jumps in the beatbox output from time to time while we either varied the carrier frequency or the RF amplitude.
Also the beatbox output shows high frequency oscillations at ~95MHz (source unknown). It is for sure that the beatbox is not behaving the way it should
but we could not tell more or troubleshoot with the beatbox mounted on the rack.
I am going to let Annalisa do her Y arm ALS scan tonight and pull out the beatbox tomorrow to fix it. |
8818
|
Wed Jul 10 02:10:41 2013 |
manasa | Update | Green Locking | Beatbox gets a makeover |
Quote: |
[Koji, Manasa]
I wanted to investigate on the ALS electronics(in particular the beatbox and the phase tracker) and find out if the beatbox is showing a linear behavior
as we expect it to and as to why we have been seeing sudden jumps at the phase tracker output.
I have been using the Xarm part of the beabox.
I used Marconi as well as signal generator to do frequency sweep/modulation at the RF input of the beatbox and looked at the I_MON output of the beatbox.
We observed sudden jumps in the beatbox output from time to time while we either varied the carrier frequency or the RF amplitude.
Also the beatbox output shows high frequency oscillations at ~95MHz (source unknown). It is for sure that the beatbox is not behaving the way it should
but we could not tell more or troubleshoot with the beatbox mounted on the rack.
I am going to let Annalisa do her Y arm ALS scan tonight and pull out the beatbox tomorrow to fix it.
|
The beatbox output showed high frequency oscillations during the troubleshooting process yesterday. I removed the beatbox from the rack. With no RF inputs, just powering the beatbox showed these high frequency oscillations at the beatbox output. This confirms that these oscillations are from the op-amp AD829JR. I replaced these with low noise OP27G. Also I removed the AD829JR that were soldered to the frequency divider and comparator which are not being used. Output buffer U10 was also removed.
After replacing with OP27G, I rechecked the beatbox with and without the RF input. There were no more high frequency contaminations and beatbox seemed to behave as it is supposed to when a frequency modulated RF input is fed. I put the beatbox back on the rack and did a quick recheck.
Before (top) and after (bottom) pictures
 
 
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8820
|
Wed Jul 10 11:27:02 2013 |
manasa | Update | Green Locking | X arm beatnote found |
I found the beat note for X arm. I did not change anything this morning (to the best of my knowledge). Hooking up the spectrum analyzer, I could find the beatnote signal at the PD RF output, after the amplifier and also at the MON port of the beatbox. I still don't know what changed from the last night set of trials  |
8824
|
Thu Jul 11 00:30:27 2013 |
manasa | Update | Green Locking | X arm ALS post-beatbox makeover |
I ran a series of diagnostics on the X arm ALS to look at how the beatbox behaves after the makeover.
Diagnostic tests run:
1. X arm ALS in-loop spectrum
2. X arm ALS out-of loop spectrum
3. X ALS scan of the X arm cavity
The noise suppression looks better after the makeover at the lower frequencies. To suppress the noise at high frequencies, we would have to add more whitening filters. |
Attachment 1: XALS_inloop.pdf
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Attachment 2: ALS_outloop.pdf
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8826
|
Thu Jul 11 07:34:42 2013 |
manasa | Update | LSC | Yarm held nicely on IR resonance with ALS, PRMI+arm attempt |
Quote: |
We knew that the Yarm was well aligned, since our IR resonance was > 0.98, but it had been a while since we had aligned the X arm.
|
The X arm was locked with TRX>0.98 earlier last night while I was measuring the out of loop noise of the phase tracker. |
8835
|
Fri Jul 12 12:30:47 2013 |
manasa | Update | General | Halogen illumination cables disconnected |
Quote: |
Alex and Steve,
Old halogen chamber illuminator cabling disconnected and potenciometer board removed at 1Y1 in order to give room for pd calibration fibre set up.
|
During the process, they had also removed the power cable to the ITMY camera. Steve and I fixed this...so the camera is back. |
8837
|
Fri Jul 12 12:51:16 2013 |
manasa | Update | LSC | PRMI + ALS automation |
Quote: |
We talked about how it should be automated.
We'll gradually offload the switching works on scripts.
|
Here is the list of automations that we need to work on for less hectic PRMI+ALS trials.
1. Enable/Disable ASC when PRMI is locked/unlocked.
2. Smooth transfer from REFL33/AS55 to REFL165 when PRMI is locked.
3. Change actuation from the ITMs to BS and PRM after PRMI lock.
4. Enable ALS.
5. IR resonance scan using ALS. |
8841
|
Fri Jul 12 23:13:32 2013 |
manasa | Update | Green Locking | ALS sensor noise |
[Annalisa, Koji, Manasa]
In order to improve the ALS stability we went ahead to check if we are limited by the sensor noise of ALS.
What we did:
RF signals similar to the beatnote were given at the RF inputs of the beatbox.
The frequency of the RF signal was set such that I_OUT was zero (zero-crossing point of the beatbox).
We measured the noise spectrum of the phase tracker output.
Measurements:
Plot 1: X ALS noise spectrum
Plot 2: Y ALS noise spectrum
Discussion:
The X arm ALS noise is not limited by the sensor noise...which means we shoudl come up with clever ideas to hunt for other noise sources.
But this does not seem to be the case for the Y arm ALS. The Y arm part of the beatbox is noisy for frequencies < 100Hz.
After looking into the details and comparing the X and Y arm parts of beatbox, it looks that amplitude of the beat signal seem to affect the Y arm ALS noise significantly and changes the noise spectrum.
To do:
Investigate the effect/limitations of amplitude of the beatnote on the X arm and Y arm beatbox.
|
Attachment 1: X_ALS_0712.pdf
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Attachment 2: Y_ALS_0712.pdf
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8858
|
Tue Jul 16 15:22:27 2013 |
manasa | Update | CDS | Front ends back up |
c1sus, c1ioo, c1iscex and c1iscey were down. Why? I was trying to lock the arm and I found that around this time, several computers stopped working mysteriously. Who was working near the computer racks at this time???
I did an ssh into each of these machines and rebooted them sudo shutdown -r now
But then I forgot / neglected/ didn't know to bring back some of the SLOW Controls computers because I am new here and these computers are OLD. Then Rana told me to bring them back and then I ignored him to my great regret. As it turns out he is very wise indeed as the legends say.
So after awhile I did Burtgooey restore of c1susaux (one of the OLD & SLOW ones) from 03:07 this morning. This brought back the IMC pointing and it locked right away as Rana foretold.
Then, I again ignored his wise and very precious advice much to my future regret and the dismay of us all and the detriment of the scientific enterprise overall.
Later however, I was forced to return to the burtgooey / SLOW controls adventure. But what to restore? Where are these procedures? If only we had some kind of electronics record keeping system or software. Sort of like a book. Made of electronics. Where we could LOG things....
But then, again, Rana came to my rescue by pointing out this wonderful ELOG thing. Huzzah! We all danced around in happiness at this awesome discovery!!
But wait, there was more....not only do we have an ELOG. But we also have a thing called WIKI. It has been copied from the 40m and developed into a thing called Wikipedia for the public domain. Apparently a company called Google is also thinking about copying the ELOG's 'find' button.
When we went to the Wiki, we found a "Computer Restart Procedures" place which was full of all kinds of wonderous advice, but unfortunately none of it helped me in my SLOW Controls quest.
Then I went to the /cvs/cds/caltech/target/ area and started to (one by one) inspect all of the targets to see if they were alive. And then I burtgooey'd some of them (c1susaux) ?? And then I thought that I should update our 'Computer Restart Procedures' wiki page and so I am going to do so right now ??
And then I wrote this elog.
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8878
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Fri Jul 19 12:00:12 2013 |
manasa | Update | Green Locking | ALS Y performance with the new whitening filter |
Quote: |
(Manasa downloaded the 2k sampled data so that we can use this for presentations.)
|
Path to data (retreived using getdata)
/users/manasa/data/130717/YALS_scan |
8879
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Fri Jul 19 12:02:18 2013 |
manasa | Update | LSC | PRMI+Y arm ALS success! |
Data retrieved using getdata (30 minutes trend) saved at
/users/manasa/data/130717/PRMI_YALS |
8880
|
Fri Jul 19 12:23:34 2013 |
manasa | Update | CDS | CDS FE not happy |
I found CDS rt processes in red. I did 'mxstreamrestart' from the medm. It did not help. Also ssh'd into c1iscex and tried 'mxstreamrestart' from the command line. It did not work either.
I thought restarting frame builder would help. I ssh'd to fb. But when I try to restart fb I get the following error:
controls@fb ~ 0$ telnet fb 8088
Trying 192.168.113.202...
telnet: connect to address 192.168.113.202: Connection refused

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8894
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Mon Jul 22 21:23:04 2013 |
manasa | Update | General | Vent preparation - In progress |
[Gautam, Manasa]
Green steering mirrors have been swapped with PZT mirrors at the X end table. We aligned the green to the X arm.
X arm green transmission +PSL green ~ 0.95
That's better than before the swap...woohooo  |
8899
|
Tue Jul 23 03:43:32 2013 |
manasa | Update | General | Vent preparation - In progress |
There seems to be an unexplained oscillation in X arm cavity transmission for IR when the cavity is locked using the POX error signal.
Their origin is not related to the oplevs because the oscillation does not exist when LSC is OFF and the arms are controlled only by the oplevs and OSEMs. |
8923
|
Thu Jul 25 13:54:35 2013 |
manasa | Update | General | PR3 clamped and Y arm is back flashing |
[Jenne, Annalisa, Manasa]
After yesterday's flipping of PR3, we lost our input pointing. Koji spent a few hours last night but couldn't restore the Y arm. I did my set of trials this morning which also didn't help.
So Jenne and I went ahead and requested Steve to get the ETMY door off.
We set the tiptilts TT1 and TT2 to the slider values from yesterday and started aligning the PR3 to hit the center of ITMY.
When we were hitting close to the center of ITMY, we decide to use the tip-tilts because the movement of PR3 was coarse at this point.
We used TT1 to get the beam to the center of ITMY and TT2 to get the beam at the center of ETMY. We did this iteratively until we were at the center of both the ITMY and ETMY.
We then went to fix IPANG.
The IPANG steering mirror on the BS table was steered to hit the center of the steering mirrors at the ETMY table. We aligned the beam to the IPANG QPD on the green endtable. The steering mirror on the BS table was then steered to misalign the beam in pitch by an inch at the last IPANG steering mirror. This should fix the IPANG clipping we have everytime we pump down.
We closed the chambers with light doors and saw IR flashing in the arm cavity. Koji is now trying to lock the cavity with IR. |
8929
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Fri Jul 26 22:45:14 2013 |
manasa | Update | General | Vent progress |
[Koji, Manasa]
The arms were brought back to resonance after yesterday's vent work.
DCPD gains were changed (TRX gain from -0.002 to -0.04; TRY gain changed from 0.002 to 0.04) to lock the arm with low power.
X arm and Y arm were locked for IR.
We then decided to align IPANG because the input pointing seemed good - the right time to fix IPANG. The IPANG spot at the last in-vac steering mirror was aligned to be an inch low in pitch.
We then aligned SRC. SR2 and SR3 were adjusted to center the beam at SRM. SRM was aligned to the retro-reflected beam until we saw flashes. But this position of SRM is not at the good OSEM range. We should correct the SRM suspensions. We postponed this activity for next week and went ahead to look at the status of the AS beam.
Looking through the window and using IR viewer were not convincing enough. We will have to get the access connector out on Monday to do the AS alignment.
We then closed the chamber with light doors and locked the arm cavities again. We brought SRC and PRC to resonance and saw strong flashes at the BS_PRM camera.
To do:
SRM need to be moved in order to remove the big bias in yaw
SRM OSEMS need to be adjusted
Access connector should come out
AS needs to be aligned satisfactorily
ITMX oplev steering mirrors in vacuum should be checked.
|
8937
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Tue Jul 30 11:30:55 2013 |
manasa | Update | General | ITMX oplev |
Quote: |
[Koji, Manasa, Sujan]
The ITMX oplev was also checked from the windows without removing the door.
The beam is actually hitting the right positions of the steering mirror and the test mass
although there are lots of stray beams because of the BS oplev and some halo assciated with the ITMX He-Ne laser(!?).
|
[Steve, Gautam, Manasa]
While we checked the ITMX oplev situation yesterday, we found that the beam hitting the ITM and the in-vacuum steering mirrors had a halo around them. We used the set of irides in the path of the ingoing beam and cut the stray light around the beam. This reduced the intensity of the halo around the mirrors. We noticed that the halo accounted for 2000 counts of 6500 at the oplev QPD. We tried changing the laser and this did not make the situation any better.
Also there are a couple or more strong stray beams from the BS oplev.
Thoughts:
I suspect that the BS oplev leakage is messing with the ITMX oplev. Why?? We have been seeing the breathing of transmitted beam from the X arm cavity and the shadow sensor readings have been bigger than usual since the last vent (when we changed the BS oplev path). Also, the ingoing oplev beam is close to clipping at the PR2 stack.
I think it would be best to open the ITMX chamber and modify the in-vac steering mirror layout of the oplev. |
8939
|
Tue Jul 30 15:38:24 2013 |
manasa | Update | General | ITMX oplev |
Quote: |
I wonder what optics is causing the halo on the oplev beam.
It this comes from any uncoated lens (or similar) it should be identified.
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We identified this to be coming from the uncoated concave lens that we have right after the He-Ne laser which should also be replaced in addition to the other problems with the oplev. |
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Tue Jul 30 18:56:31 2013 |
manasa | Update | General | ITMX chamber vented/Closing plan |
[Koji,Manasa]
We removed the ITMX heavy door to fix the oplev situation.
My Plan for closing:
Today: I will work on the ITMX oplev situation today and go through the vent close-up checklist as far as I can get.
Tomorrow: We will do the final alignment check tomorrow with the light doors. The access connector and heavy doors should go in place late afternoon.
Thursday: We will start pumping down early in the morning on Thursday. |
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Wed Jul 31 00:59:58 2013 |
manasa | Update | General | ITMX chamber vented/Closing plan |
My Plan for closing:
Today: I will work on the ITMX oplev situation today and go through the vent close-up checklist as far as I can get.
[Alex, Sujan, Manasa]
The ITMX oplev steering mirrors were laid out such that they were out of the way of the BS oplev leakage. But the halo associated with the He-Ne laser does exist even now. I conclude that this is something that can be dealt with after we pump down as well. So I did not change the ITMX oplev optics on the POX table.
BS, PRM, ITMY and SRM oplevs were aligned and centered.
We want to do IPANG and IPPOS alignment when the IFO is aligned satisfactorily and right before we put the heavy doors.
The arms were aligned and ASS'd before I went in to fix the oplevs. I haven't done anything but deal with the oplevs tonight. So I am being lazy by assuming the alignment is still good and calling it a night.
Tomorrow: We will do the final alignment check for the arms, PRC and SRC with the light doors on. Check IPANG and IPPOS. The access connector and heavy doors should go in place late afternoon.
Thursday: We will start pumping down early in the morning on Thursday. |
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Wed Jul 31 21:12:05 2013 |
manasa | Update | General | Pump down called off |
[Koji, Manasa]
We missed to check that we had the green transmitted to the PSL after flipping the SRC and PRC folding mirrors.
There is no green transmission reaching the PSL even after locking the arms to green.
We should fix this tomorrow. The BS heavy door should come off.
Steve! Do not start pump down tomorrow ! |
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Thu Aug 1 22:49:31 2013 |
manasa | Update | General | Green status after PR3 flipping investigated |
[EricQ, Koji, Manasa]
We opened the BS chamber to check the status of the green beams. The X green has 3 steering mirrors before they hit periscope1 and the Y green transmits through all the optics giving no way to steer it.
We agreed to start fixing the Y green. The wedge angle of PR3 is steering the transmitted beam away in both pitch and yaw. Since we are restricted only to yaw movement (done by moving the periscope), we want he wedge angle to be oriented in the yaw as well.
Right now, the wedge is oriented at about 20-30 deg off (The mark on the side of the mirror does not indicate the wedge). So we see a pitch as well as yaw misalignment in the transmitted beam. The pitch misalignment is making the beam fall off the mirrors in periscope2.
We have decided to get the wedge angle set right for PR3 and redo the alignment for IR. Once we are aligned for the IR, we will modify the green layout. |
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Mon Aug 5 18:02:34 2013 |
manasa | Update | General | Close up list checked |
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Center beam on all AS optics
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GET CAMERA IMAGES OF EVERYTHING
- We must get images right before closing, right after closing, etc.
Make sure REFL is clear
- dither PRM, see motion on AP tables
Make sure AS is clear
- dither BS/ITM, see motion on AP tables
Using IPANG/POS pick-off mirrors, center beams on:
IPPOS
IPANG (aligned low in pitch)
Check green alignment in the arms and make sure the transmitted green reaches the PSL table.
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Check all OpLevs centered, in and out of vacuum
[Jenne, Manasa]
IPANG needed to be re-aligned today. Heavy doors are in place and bolts tight (torque 25 & 45).
Steve! We are ready for pump down!
I will check the IFO alignment once again early tomorrow morning before Steve starts pumping down.
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Tue Aug 6 07:52:58 2013 |
manasa | Update | General | Ready to pump down |
I did an alignment check of the IFO before we start pumping down.
Arms were locked. PRM and SRM were aligned. Green was aligned to the arms for reference during the pump down.
Steve! It's a GO!
MC spot positions:

OSEM:

Oplevs were all centered yesterday and haven't drifted much. So I left them as is.

QPDs (IPPOS aligned from yesterday.

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Thu Aug 8 11:18:46 2013 |
manasa | Update | Computer Scripts / Programs | Unused scripts in ASS moved |
I was receiving missing path error when I was trying to measure the MC spot positions. Jenne pointed out that Koji had moved all the unused scripts in scripts/ASS to /scripts/ASS/OBSOLETE yesterday and in the process one of the scripts that the MC spot position measurement script calls for (MeasureSpotPositions.py) must have also been moved to the OBSOLETE directory. I moved the script to /scripts/ASS/MC so that we know the script is being used and also changed its path in the main script. |
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Mon Aug 12 21:27:03 2013 |
manasa | Update | CDS | c1iscex needs help |
I started to modify the c1asx model to reduce the RFM model from hitting its max time.
Instead of bringing in ASS, I have modified ASX to do everything and only the clock signals to ITMX pitch and yaw are now going through RFM. RFM is still hitting 62usec and I suppose that is because of the problems with c1iscex.
c1iscex not happy
Cause and symptoms
While restarting the models, c1iscex crashed a couple of times because of some errors and had to be powercycled. The models were modified and they seem to start ok.
But it looks like there is something wrong with c1iscex since the models were started. The GPS time is off and C1:DAQ-DC0_C1X01_CRC_SUM keeps building up even for c1x01 which was left untouched.
Trial treatments
1. Since c1x01 ans c1spx were not touched,c1scx and c1asx were killed and we tried to start the other models. This did not help.
2. Koji did a manual daqd restart which did not help either.
We are leaving c1iscex as is for the time being and calling Jamie for help.
P.S. While making the models, I had created IPCx_PCIE blocks in c1iscex which do not exist. I changed them to RFM and SHMEM blocks. This did not allow me to compile the model and was only spitting errors of IPCx mismatch. After some struggle and elog search I figured out from an old elog that eventhough the IPCx blocks are changed in the model, the old junk exists in the ipc file in chans directory. I deleted all junk channels related to the ASX model. The model compiled right away. |
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Tue Aug 13 21:09:03 2013 |
manasa | Update | Green Locking | Arms ready for ALS |
I aligned both the X and Y end green to the arms.
The transmitted green were aligned at the PSL table green optics to the beat PDs.
Beat notes were retrieved.
To do:
1. Check Y arm ALS with previous performance.
2. Troubleshoot X arm ALS.
3. Edit the automation scripts for ALS.
4. Modify ALS model to talk to LSC instead of suspension models. |
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Thu Aug 15 12:30:17 2013 |
manasa | Update | Green Locking | Lost beat notes |
[Koji, Nic, Manasa]
Update from last night.
Koji and I realigned the green optics on the PSL to start working on the ALS.
We set on a beat note search. We couldn't find the beat note between any of the arm green transmission and the PSL green. All we could see was the beat between the X arm and the Y arm green leakage.
Since we had the beatnote between the 2 green transmission beams, we decided to scan the PSl temperature. We scanned the SLOW actuator adjust of PSL; but couldn't locate any beat note. The search will continue again today. |
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Thu Aug 15 19:05:07 2013 |
manasa | Update | Green Locking | ALS out of loop noise |
Beat notes were recovered for both the arms.
I locked the arms to IR using PDH and measured the ALS out of loop noise at the phase tracker output.
The Y arm has the same 300Hz/rtHz rms. The X arm rms noise measures nearly the same as the Y arm in the 5-500Hz region (X arm has improved nearly 10 times after the last whitening filter stage change old elog ).
The noise in the ALSX error signals could be related to the bad alignment and conditions at the X end. |
Attachment 1: ALS_OutLoop.pdf
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Mon Aug 19 16:18:56 2013 |
manasa | Update | Green Locking | Xend green aligned |
ASX scripts for PZT dither have been fixed appropriately. Script resides in scripts/ASX.
You can run the scripts from the ASX medm screen now. |
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Mon Aug 26 19:31:22 2013 |
manasa | Update | SUS | PRM, ITMY watch dogs |
PRM and ITMY were found with their watchdogs shutdown this afternoon (cause unknown). I re-engaged them. |
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Mon Aug 26 19:54:15 2013 |
manasa | Update | CDS | c1als model modified |
I had made changes to the c1als model a couple of weeks ago. I had removed all the beat_coarse channels that had existed from pre-phase tracker era.
Also, I forgot to elog about it then. This dawned on me only when I found that c1als isn't working the way it should right now.

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