 Thu Jul 29 15:35:21 2010, josephb, kiwamu, Update, CDS, Working out ADC/DAC/BO wiring
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We are currently using the SUS wiring diagram found on Ben Abbott's page (link here) to determine
the ADC/DAC/BO channel numbers for each individual optics inputs and outputs. Basically it involves tracking the paths back from the Pentek's, XY220,
and IC110Bs to a point where we can identify it as a Coil UL or a PD whitening filter control or whatever it might be. |
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Thu Aug 13 20:32:07 2015, Ignacio, Update, LSC, Working towards YARM FF
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The mode cleaner FF static filtering is by no means done.
More work has to be done in order to succefuly implement it, by the means of fine tuning the IIR fit and finding better MISO Wiener filters.
I have begun to look at implementing FF to the YARM cavity |
Thu Jan 3 21:17:49 2019, rana, Configuration, Computers, Workstation Upgrade: Donatella -> Scientific Linux 7.2 
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donatella was one of our last workstations running ubuntu12. we installed SL7 on there today
had to use a DVD; wouldn't boot from USB stick
made sure to use userID=1001 and groupID=1001 at the initial install part
went
to the Keith Thorne LLO wiki on SL7
The 'yum update' command failed due to a gstreamer conflict. I did "yum |
 Tue Oct 15 17:22:26 2019, gautam, Update, General, Workstation computers back on UPS
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Batteries + power cables replaced, and computers back on UPS from today ~3pm.
Quote:
The UPS is now incessantly beeping. I cannot handle this constant sound so I shut down all the control room workstations |
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Mon Oct 14 17:24:28 2019, gautam, Update, General, Workstation computers taken off UPS (temporarily)
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The UPS is now incessantly beeping. I cannot handle this constant sound so I shut down all the control room workstations and moved the power strip hosting
the 4 CPUs to a wall socket for tonight. Chub and I will replace the UPS batteries tomorrow. |
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Tue Oct 22 18:55:55 2013, rana, Update, CDS, Workstation swap: Rosalba to ???
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We got a new computer from Xi computer corp. I am currently installing Ubuntu 10.04 LTS on to it to start with and then will move on to 12 if we can
figure out a way to test it besides "I guess it should work?"
Rosalba has been removed and put onto the old Jamie desk. Old Jamie desk also has a Mac Mini running on there. |
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Wed Oct 23 22:11:20 2013, rana, Update, CDS, Workstation swap: Rosalba to ???
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I've finished setting up the fstab on Chiara and the upgrade to Ubuntu 12 seems to have gone well enough. She's fast:
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Thu Jun 12 11:03:11 2014, Koji, Frogs, General, World Cup Soccer 2014
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Thu Jun 12 12:30:50 2014, den, Frogs, General, World Cup Soccer 2014
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Quote:
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Thu Aug 7 13:39:41 2014, Nichin, Update, Computer Scripts / Programs, Wrapping up PDFR
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1)The PDFR scripts have all been migrated into /scripts/PDFR/
2) The MEDM screen to run PDFR is /medm/MISC/PDFR.adl
3) A new button has been added on sitemap to open the above medm window. |
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Tue Aug 1 19:23:06 2017, rana, Update, ALS, X - arm alignment
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Rana, Naomi
We dither locked the X arm and then aligned the green beam to it using the PZTs. Everything looks ready for us to do a mode scan tomorrow.
We got buildup for Red and Green, but saw no beat in the control room. |
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Fri May 16 10:54:42 2014, ericq, Update, LSC, X Arm ALS Noise coming in and out
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Den and I spent some time with the interferometer last night with hopes of bringing in the AO path, but were stymied by the (re)occurrence of the anomalously
high low frequency motion of the Xarm, as seen by fluctuations of TRX from .9 to .2 while "held" on resonance.
Jenne reported that they weren't seeing it earlier in the evening, and then it started again when I showed up. Holding the arms on IR, we could |
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Fri May 16 11:22:23 2014, Steve, Update, LSC, X Arm ALS Noise coming in and out
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Quote:
Den and I spent some time with the interferometer last night with hopes of bringing in the AO path, but were stymied by the (re)occurrence |
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Fri Aug 18 23:59:53 2017, gautam, Update, ALS, X Arm ALS lock
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[ericq, gautam]
I was just getting the IFO aligned, and single arm lock going, when EricQ came in and asked if we could get some ALS data.
ALS
beats seemed fine, in particular the X-Arm. The broad hump around ~70Hz that was present in my previous |
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Sat Aug 19 01:35:08 2017, ericq, Update, ALS, X Arm ALS lock
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My motivation tonight was to get an up-to-date spectrum of a calibrated measurement of the out-of-loop displacement of an arm locked on ALS (using
the PDH signal as the out-of-loop sensor) to compare the performance of ALS control noise with the Izumi et al green locking paper.
I was able to fish out the PSD from the paper from the 40m svn, but the comparison as plotted looks kind of fishy. I don't see why the noise |
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Tue Nov 18 19:44:53 2008, Alberto, Update, General, X Arm Cavity "Negative" FSRs Measured
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Previous measurements on the X arm cavity revealed a shift of the frequencies of the cavity resonances from where one would expect these to be by just looking
at integer multiples of the cavity FSR. In particular, plotting the resonant frequencies versus the order of their occurrences while sweeping the laser
frequency (in our case that of the beat between the two lasers), the linear fit of the data contained an unwanted offset:
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Thu Nov 5 22:30:09 2009, Alberto, Update, LSC, X Arm Cavity Transfer Function
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It seems that just repeating the measurement was enough to get a good transfer function of the x arm cavity. Here's what I got.
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Wed Nov 4 23:17:51 2009, Alberto, Update, LSC, X Arm Cavity transfer Function
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I measured the transfer function between MC_TRANS and TRX and I'm attaching the result.
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Thu Nov 5 05:07:22 2009, rana, Update, LSC, X Arm Cavity transfer Function
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I would have guessed that you have to calibrate the detectors relative to each other before trying this. Its also going to be tricky if you use 2 different
kinds of ADC for this (c.f. today's delay discussion in the group meeting).
I think Osamu used to look at fast transmission signals by making sure the PD at the end had a 50 Ohm output impedance and just drive the 40m long |
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Thu Nov 5 19:25:11 2009, Alberto, Update, LSC, X Arm Cavity transfer Function
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Quote:
I would have guessed that you have to calibrate the detectors relative to each other before trying this. Its also |
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Wed May 27 17:14:08 2015, ericq, Update, LSC, X Aux Laser crystal temperature changed
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Rana suspects that the lack of X beatnote is related to the PSL laser temperature change (ELOG
11294).
I used the information on the wiki and old elogs (wiki-40m, |
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Mon Feb 27 18:35:45 2012, Jenne, Update, Green Locking, X Beat Search
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Meh. I've searched in steps of 20 counts in C1:GCX-SLOW_SERVO2_OFFSET units (16 bit +\- 10V DAC, and 1GHz/V coeffecient for the Xgreen aux laser
means this is ~0.6MHz per 20 count step). I went from -400cts to +800 cts and haven't found the beatnote yet. Meh.
Both PSL green and Xgreen beams are going to the Xgreen BBPD. Both beams are easily visible, so while I didn't actually measure the power, |
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Fri Oct 6 17:08:09 2017, Steve, Update, ALS, X End table beam traps corrected
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There are no more double sided tape on this table.
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Thu Sep 21 01:55:16 2017, rana, Update, ALS, X End table of Shame
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Image #1: No - we do not use magnetic mounts for beam dumps. Use a real clamp. It has to be rigid. "its not going anywhere" is a nonsense statement;
this is about vibration amplitude of nanometers.
Image #2: No - we do not use sticky tape to put black glass beam dumps in place ever, anywhere. Rigid dumps only. |
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Thu Aug 2 20:47:29 2018, gautam, Summary, Electronics, X Green "Mystery" solved
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I walked down to the X end and found that the entire
AUX laser electronics rack isn't getting any power. There was no elog about this.
I couldn't find any free points in the power strip where I think all this stuff was plugged in so I'm going to hold off on resurrecting |
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Thu Aug 2 23:09:25 2018, rana, Summary, Computers, X Green "Mystery" solved
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I'm going to guess that this was me: I was disconnecting some octopus power strip nonsense down there (in particular illuminators and cameras), so
I might have turned off the AUX rack by mistake.
Quote:
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Wed Jan 24 00:58:59 2018, gautam, Update, ALS, X Green PDH modulation depth
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On Friday, while Udit and I were doing some characterization of the EX+PSL IR beat at the LSC rack, I noticed that there were sidebands around the main
beat peak at 20dBm lower level. These were offset from the main peak by ~200kHz - I didn't do a careful characterization but because of the symmetric
nature of these sidebands and the fact that they appeared with the same offset from the main peak for various values of the central beat frequency, I hypothesize |
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Wed Apr 1 23:56:36 2015, ericq, Update, LSC, X Green Power drifting
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Something funky is happening with the green light locked to the X arm. The green transmitted power
is drifiting around. Maybe something weird is happening with the doubler? The digital thermal feedback loop is not on.
The green has been locked on a TM00 mode this whole time. The step in power is me closing the PSL green |
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Thu Apr 2 01:28:34 2015, Jenne, Update, LSC, X Green Power drifting
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Have you tried a different set of laser temperatures? I don't remember the value for the Xgreen, but whatever the value that matches PSL of
0.62ish and above seems to put the Xgreen laser at a bad temperature. I think this is the mode-hopping region, and we sometimes lock to the wrong
mode. |
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Thu Apr 2 01:45:44 2015, Jenne, Update, LSC, X Green Power drifting
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Quote:
Have you tried a different
set of laser temperatures? |
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Wed Jan 28 17:39:17 2015, Koji, Configuration, IOO, X Trans Table less crazy but not enough yet
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The X-end IR Trans path was cleaned up.
I have been investigating the Xarm ASS issue. The Xarm ASS sensors behaved not so straight forward.
I went to the X-end table and found some suspect of clipping and large misalignmnet in the IR trans path. |
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Thu Jan 29 17:20:58 2015, manasa, Configuration, IOO, X Trans Table less crazy but not enough yet
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[Koji, Manasa]
We cleared up some optics and optomechanics at the X end table that are not being used and moved them to the SP table. [Ed by KA:
They seemed to be leftover of the other projects. I blame them] |
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Tue Nov 10 13:02:36 2009, Alberto, Update, LSC, X and Y Arm Cavity Poles Measurement
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From fitting the arm cavity transfer functions I got the following values for the cavity pole frequencies.
X ARM: fp_x = (1720 +/- 70) Hz
Y ARM: fp_y = (1650 +/- 70) Hz |
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Wed Jun 8 16:41:48 2011, valera, Update, ASS, X and Y arm dither alignment status
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The current status of the dither alignment system:
- Both Xarm and Yarm alignment are working. The scripts are: scripts/autoDither/alignX(Y). |
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Mon Feb 10 22:21:55 2014, manasa, Update, Green Locking, X and Y arm green tuned
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Y arm green: Nothing much was disturbed. I touched the steering mirrors and brought GTRY from 0.2 to 0.9.
X arm green: The PDH lock was not very stable mostly because of the low power in green. I |
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Thu Feb 13 16:48:33 2014, Steve, Update, Green Locking, X and Y arm green tuned details
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Quote:
Y arm green: Nothing much was disturbed. I touched the steering mirrors and brought |
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Mon Sep 30 17:55:45 2013, manasa, Update, Green Locking, X and Y arm transmission needs to be decoupled
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[Masayuki, Manasa]
Problem
We wanted to lock both the arms using ALS and get IR to resonate while arms are held using ALS. The X arm was locked using ALS and offsetter2 was |
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Fri Nov 9 00:23:12 2007, pkp, Update, OMC, X and Z resonances
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I got a couple of resonance plots going for now. I am still having trouble getting the Y measurement going for some reason. I will investigate that tommorow.
But for tonight and tommorow morning, here is some food for thought. I have attached the X and Z transfer functions below. I compared them to Norna's plots
- so just writing out what I was thinking -
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Mon Mar 27 16:01:55 2017, Steve, Update, PEM, X arm AC set to 68F
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The X arm air conditioner was not regulating properly. The arm temp was warmer than usual. I requested thermistor calibration.
The mechanic reset the thermostate to 68F last week. It was 70-71F before. |
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Thu Jun 13 22:31:12 2013, Manasa, Summary, Green Locking, X arm ALS
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Stabilized ALS and beat frequency sweep realized.
Procedure: |
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Fri Jun 14 07:06:19 2013, Koji, Summary, Green Locking, X arm ALS
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It's nice that we are now able to scan the cavity again. We got close to PRMI+one arm one step further.
The calibration of the scan frequency and the evaluation of the in-loop/out-of-loop error signal in terms of (Hz/rtHz) would be necessary.
The beat amplitude looks actually huge aIthough I don't know where you are monitoring. |
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Thu Jul 11 00:30:27 2013, manasa, Update, Green Locking, X arm ALS post-beatbox makeover
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I ran a series of diagnostics on the X arm ALS to look at how the beatbox behaves after the makeover.
Diagnostic tests run: |
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Fri Aug 3 19:02:11 2018, gautam, Update, ASS, X arm ASS recovery
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[koji, gautam]
After I effected the series resistance change for ETMX, the X arm ASS didn't work
(i.e. IR transmission would degrade if the servo was run). Today, |
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Tue Aug 14 00:50:32 2018, gautam, Update, ASS, X arm ASS still not quite right?
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While working on the single arm alignment, I noticed that today, i was able to get the X arm transmission back to ~1.22, and the GTRX to 0.52. These
are closer to the values I remember from prior to the vent. Running the dither alignment promptly degrades both the green and IR transmissions. Since the
pianosa SL7 upgrade, I can't use the sensoray to capture images, but to me, the spot looks a little off-center in Yaw on ETMX in this configuration, |
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Wed Jan 7 11:20:22 2015, Steve, Update, LSC, X arm T-QPD gets SM1 thread adapter
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C1:SUS-ETMX_QPD is removed and internal SM1 thread adapter epoxied into position
as it is at the Y end
This adapter will take FL1064-10 line filter holder |
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Tue Feb 4 00:42:18 2014, Koji, Update, General, X arm aligned for IR/GR
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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.
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Thu Jun 21 15:36:51 2012, yuta, Update, Locking, X arm alignment
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I aligned X arm so that the beam spot comes roughly on the center.
1. Use ITMX and ETMX (mainly ITMX) to make beam spot come on center of the optic using eyeball. |
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Sun Feb 13 15:02:23 2011, kiwamu, Update, Green Locking, X arm beam offcentering has been measured
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The amounts of the X arm's beam off-centering have been measured by the
A2L technique.
So now we are able to start aligning the IR beam axis in a quantitative |
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Wed Jul 10 11:27:02 2013, manasa, Update, Green Locking, X arm beatnote found
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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 |
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Thu Mar 14 17:31:57 2013, Manasa, Update, Green Locking, X arm green locked in TEM00
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Quote:
Manasa has done some work to get the Xgreen aligned, so I'll switch to trying to find that beatnote for now. |