 Fri Jun 20 08:30:27 2008, stiv, Update, Photos, 40m summer line up 2008 
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atm1: John, Alberto, Yoichi, Koji, Masha, and Sharon
atm2: surf students Max of CIT, Sharon of MIT, Masha of Harvard, Eric of CIT not shown |
 Fri Jun 22 15:22:39 2018, sudo, Update, CDS, DTT working
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Quote:
Seems like DTT also works now. The trick seems to be to run sudo /usr/bin/diaggui instead of just |
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Wed Mar 2 22:57:57 2011, suresh, Summary, General, Stuff from LLO
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Here is a partial list of stuff which is being packed at LLO to be shipped to CIT. The electronics ckt boards are yet to be added to this list.
Will do that tomorrow.
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Mon Mar 7 17:58:14 2011, suresh, Summary, General, Stuff from LLO
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Here is the updated list. These lists were used as packing lists and therefore are organised by Box #. |
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Wed Apr 20 22:29:07 2011, suresh, Update, RF System, Plan for LSC rack
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The suggested layout of the 1Y2 Rack is shown below.
To simplify the wiring, I have largely kept demod boards with the same same LO frequency close to each other.
The Heliax cables land on the top and bottom of the of subracks. These are currently flexible plastic sheets. Steve has agreed to replace |
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Wed Jul 20 17:43:33 2011, suresh, Update, Computers, restarted the frame builder
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I restarted the frame builder in the last 15mins.
I was making a change to a DAC channel in the C1IOO model. |
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Thu Jul 21 16:05:15 2011, suresh, Update, IOO, PSL beam into MC realigned
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I realigned the PSL beam going into the MC.
The MC beam was realigned so as to maximise the power in the MC. I minimised the MC_RFPD_DCMON dial on the MC_ALIGN screen while adjusting
the two zig-zag mirrors at the end of the PSL table. |
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Sat Nov 26 07:22:20 2011, suresh, Update, Computers,
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| c1sus has been shutdown so that the optics dont bang around. This is because the watch dogs are not working. |
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Thu Mar 22 17:41:15 2012, suresh, Update, CDS, c1scx and c1scy not properly running
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Quote:
It seems that neither c1scx nor c1scy is working properly as their ADC counts are showing digital-zeros. |
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Mon Jan 28 21:36:44 2013, tall guy, Frogs, General, small people on notice
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| If I catch anyone putting small booties into the large bootie bin, I will make said person eat small booties. |
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Thu Oct 28 19:10:26 2010, tara, Update, Electronics, TTFSS for 40m
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I keep a set of new TTFSS for 40m in electronic cabinet along the North arm.
The set number is #6. It is working and has not been modified by me.
Other two sets,# 5 and #7, are kept at PSL lab. |
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Mon Apr 11 20:03:05 2011, tara, Update, Electronics, TTFSS for 40m
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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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Tue Apr 10 11:08:29 2012, tara, Update, PSL, curved mirror behind AOM removed
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We removed the curved mirror behind the AOM (ROC=0.3m) on PSL table. The mirror is now in PSL lab. See PSL:905
for more detail. |
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Wed Jan 16 10:57:37 2013, tara, Summary, IOO, Noise budget for MC
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I calculated thermal noise in mode cleaner (MC) mirrors and compared it with the measured MC noise. Thermal noise won't be a significant noise source
for MC.
== Motivation== |
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Wed Jul 7 00:15:29 2010, tara,Rana, Summary, PSL, power spectral density from RefCav transmitted beam
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I measured the RC transmitted light signals here at the 40m. I made all connections through the PSL patch panel.
Other than two steering mirrors in front of the periscope, and the steering |
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Tue Jul 13 21:04:49 2010, tara,rana, Summary, PSL, Transfer function of FSS servo
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I measured FSS's open loop transfer function.
For FSS servo schematic, see |
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Mon Sep 13 22:51:07 2010, tara,valera, Configuration, PSL, beam scan for RCAV
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On Friday, Valera and I calculated the modematching for reference cavity from AOM.
We scan the beam profile where the spot should be.
The first beam waist in the AOM is 103 um, the lens (f= 183 mm, I'm not sure if I have the focal length right) is 280 mm away. |
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Thu Jul 26 01:52:01 2018, terra, Update, Thermal Compensation, heater work update
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Just a quick update: over the past few days we've taken (at least) 5 scans around each peak [carrier - HOM3] at 9.4V/0.8A, 4 scans around [carrier
- HOM5] at 12V/0.9A hot state with the reflector setup. We also have (at least) 5 scans of carrier - HOM5 in cold state. I attach a rough overview of the
peak magnitude shifts in the first attachment. Analysis ongoing. All data stored in annalisa/postVent/{date} |
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Sat Jul 28 00:45:11 2018, terra, sandrine, Summary, Thermal Compensation, Heater measurements overview 7x
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[Sandrine, Koji, Terra]
Summary: We completed multiple scans at different heating powers for the reflector set up, observing unique HOM peak shifts
of tens of kHz. We also observed HOM5 shifts with the cylinder set up. Initial Lorentzian fittings of the magnitude give tens of Hz resolution. I summarize |
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Sun Feb 24 10:51:58 2008, tf, Frogs, Environment, 40m in phdcomics?
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| [url=http://www.phdcomics.com/comics/archive.php?comicid=977][img]http://www.phdcomics.com/comics/archive/phd021308s.gif[/img][/url] |
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Mon Oct 29 23:25:42 2007, tobin, Software Installation, CDS, frames mounted
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I mounted the frames directory on mafalda and linux3. It's intentionally not listed in the /etc/fstab so that an fb crash won't prevent the controls machines
from booting. The command to mount the frames directory is:
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Tue Oct 30 16:55:40 2007, tobin, Routine, , Drag-wiping perfected
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Steve, Tobin
Steve procured an assortment of syringes from the bio storeroom and we practiced drag-wiping the SOS in the flow bench. Using a 50 microliter Hamilton |
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Tue Oct 30 19:32:13 2007, tobin, Problem Fixed, Computers, conlogger restarted
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I noticed that the conlogger wasn't running. It looks like it hasn't been running since October 11th. I modified the restart_conlogger script to insist
that it run on op340m instead of op440m, and then ran it on op340m. |
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Tue Oct 30 20:15:24 2007, tobin, Other, Environment, earthquake
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Rana, Tobin
Largish (M5.6) earthquake in San Francisco sent our optics swinging. |
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Wed Oct 31 15:02:59 2007, tobin, Routine, IOO, Mode Cleaner Mode Tracking
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I processed the heterodyned mode cleaner data yesterday, tracking the three 28 kHz modes corresponding to MC1, MC2, and MC3. Unfortuntately the effect
of our MC power chopping is totally swamped by ambient temperature changes. Attached are two plots, one with the tracked mode frequencies, and the other
containing dataviewer trends with the MC transmitted power and the room temperature. Additionally, the matlab scripts are attached in a zip file. |
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Thu Nov 1 11:45:30 2007, tobin, Configuration, IOO, Mode cleaner drag-wiping
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Andrey, Bob, David, John Miller, Rana, Rob, Steve, Tobin
Yesterday we vented the vacuum enclosure and opened up the chamber containing MC1 & MC3 by removing the access connector between that chamber and the OMC |
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Tue Nov 6 16:48:54 2007, tobin, Configuration, Computers, scopes on the net
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I configured our two 100 MHz Tektronix 3014B scopes with IP addresses: 131.215.113.24 ([url=http://scope0/]scope0[/url]) and 113.215.113.25 ([url=http://scope1/]scope1[/url]).
Let the scripting commence!
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Tue Nov 6 18:18:15 2007, tobin, Configuration, Computers, I broke (and fixed) conlogger
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It turns out that not only restart_conlogger, but also conlogger itself checks to see that it is running on the right machine. I had [url=http://dziban.ligo.caltech.edu:40/40m/32]changed
the restart_conlogger script[/url] to run on op340, but it would actually silently fail (because we cleverly redirect conlogger's output to /dev/null).
Anyway, it's fixed now: I edited the conlogger source code where the hostname is hardcoded (blech!) and recompiled.
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Tue Nov 6 23:45:38 2007, tobin, Configuration, Computers, tektronix scripts!
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I cooked up a little script to fetch the data from the networked Tektronix scope. Example usage:
[FONT=Courier]linux2:scripts>[b]tektronix/tek-dump scope0 ch1 foo.csv[/b][/FONT]
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Wed Nov 7 14:05:59 2007, tobin, Configuration, IOO, MC ringdown
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Modeling the mode cleaner as a simple cavity with all losses lumped together, we expect the cavity power to be
attenuated by a factor (1-L) after each interval (2l/c)=1/fsr. Therefore we can get the cavity loss L
(including power lost through transmission) from the ringdown time constant tau as:
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Thu Nov 8 15:57:53 2007, tobin, Configuration, PSL, shelf removed
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I removed the sheet metal shelf from the PSL enclosure, for easier access to the ISS.
ISS investigations ongoing. |
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Thu Nov 8 18:44:01 2007, tobin, Configuration, PSL, ISS
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Tobin, Rob
With the Sense PD blocked, I adjusted the offset trim of the fourth stage in the ISS servo until the current shunt signal was zeroed. After this adjustment, |
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Wed Nov 14 12:33:35 2007, tobin, AoG, Environment, construction
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| The construction crews are running a jack-hammer right outside of the control room. |
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Wed Nov 14 12:47:19 2007, tobin, Update, PSL, ISS
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John, Tobin
With John's notch filter installed and the increased light on the ISS sensing diode, we were able to get a UGF of about 60 kHz with the gain slider set |
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Wed Nov 14 17:50:00 2007, tobin, Update, PSL, ISS
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Here's the current wiring between the ISS and its PDs:
[table border="1"]
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Thu Nov 15 18:06:06 2007, tobin, Update, Computers, alex: linux1 root file system hard disk's dying
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I just noticed that Alex made [url=http://www.ldas-sw.ligo.caltech.edu/ilog/pub/ilog.cgi?group=40m&date_to_view=11/14/2007&anchor_to_scroll_to=2007:11:14:20:00:29-aivanov]an
entry in the old ilog[/url] yesterday, saying: "[color=red][b]Looks like linux1 root filesystem hard drive is about to die. The system log is full of drive
seek errors. We should get a replacement IDE drive as soon as possible or else the unthinkable could happen.[/b][/color] 40 Gb IDE hard drive will be |
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Thu Nov 15 18:37:06 2007, tobin, Update, Computers, possible replacement for linux1's disk
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It looks like the existing disk in linux1 is a Seagate ST380013A (this can be found either via the smartctl utility or by looking at the file /proc/ide/hda/model).
It appears that you can [url=http://www.amazon.com/Seagate-ST380013ARK-Internal-Barracuda-Ultra/dp/B0000A576G/ref=pd_bbs_sr_6?ie=UTF8&s=electronics&qid=1195180463&sr=8-6]still
buy this disk from amazon[/url], though I think just about any ATA disk would work. I'll ask Steve to buy one for us. |
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Fri Nov 16 11:27:18 2007, tobin, Update, Computers, script fix
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I added a tidbit of code to "LIGOio.pm" that fixes a [url=http://lhocds.ligo-wa.caltech.edu:8000/40m/EZCA]problem with ezcastep on Linux[/url]. Scripts
such as "trianglewave" will now work on Linux.
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Fri Nov 16 14:11:26 2007, tobin, Update, Computers, op140
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| Alan called to say that Phil Ehrens will be coming by to take [b]op140[/b] off our hands. |
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Fri Nov 16 14:31:43 2007, tobin, Update, Computers, op140 disks
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| Phil Ehrens stopped by and took op140's disks. |
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Tue Nov 20 11:10:07 2007, tobin, Update, Computers, epics access from matlab
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I installed "[url=http://www.slac.stanford.edu/~strauman/labca/]labca[/url]", which allows [b]direct access to EPICS channels from within Matlab[/b]. It
comes with both Linux and Solaris binaries (and source) but I've only tried it on linux.
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Tue Nov 20 13:06:57 2007, tobin, Configuration, Computers, linux1 has new disk
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Alex put the new hard disk into linux1 along with a fresh install of linux (CentOS). The old disk was too damaged to copy.
Alex speculates that the old disk failed due to overheating and that linux1 could use an extra fan to prevent this in the future. |
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Tue Nov 27 20:47:00 2007, tobin, Update, PSL, FSS
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Rana, Tobin
We looked at the RF PD signal to the FSS (siphoning off a signal via a minicircuits directional coupler) and also took an open loop transfer function of |
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Wed Nov 28 19:44:18 2007, tobin, Update, PSL, HEPA
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| I found the HEPA turned off completely. I turned it on. |
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Wed Nov 28 21:51:52 2007, tobin, Configuration, PSL, ISS
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I replaced the front-end differential receivers for the ISS's "inner-loop" sensor and monitor diode inputs with lower-noise [url=http://focus.ti.com/docs/prod/folders/print/ths4131.html]THS4131[/url]'s
(formerly THS4151's). I verified operation by taking the transfer function from the "PD+" and "PD-" inputs (separately) to the testpoint following the
differential receiver; the surgery appears successful.
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Thu Nov 29 14:29:22 2007, tobin, Configuration, Computers, linux1 httpd/conlogger fixed
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I think I fixed the [url=http://linux1/cgi-bin/conlog_web.pl]conlogger web interface on linux1[/url].
Steps necessary to do this:
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Mon Dec 3 16:24:47 2007, tobin, HowTo, Computers, GNU screen
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[url=http://jmcpherson.org/screen.html]GNU screen[/url] is a utility that can be quite handy for managing long-running psuedo-interactive terminal programs
on remote machines. In particular, I think it might be useful in developing and testing "Matlab DMT" tools on Mafalda. |
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Mon Dec 3 17:55:39 2007, tobin, HowTo, Computer Scripts / Programs, linemon
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Matlab's Signal Processing toolbox has a [url=http://www.mathworks.com/access/helpdesk/help/toolbox/signal/index.html?/access/helpdesk/help/toolbox/signal/spectrum.html]set
of algorithms for identifying sinusoids in data[/url]. Some of them (e.g., [url=http://www.mathworks.com/access/helpdesk/help/toolbox/signal/index.html?/access/helpdesk/help/toolbox/signal/rootmusic.html&http://www.mathworks.com/cgi-bin/texis/webinator/search/]rootmusic[/url])
take the number of sinusoids to find as an argument and return the "most probable N frequencies." These could be useful in line monitoring. |
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Mon Dec 3 22:20:09 2007, tobin, Configuration, PSL, ISS
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I replaced the painfully short 1' cables on the ISS photodiodes with luxurious five foot cables, made by chopping a ten foot Amphenol cable (P/N:CS-DSPMDB09MM-010)
in half and using each half for one of the diodes. All of the ISS GND connections are wired to the PD GND, as is the PD- differential signal. The diodes
are installed on the PSL table, but I have not tested them beyond looking at the DC values as I blocked/unblocked the beam. |
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Tue Dec 4 23:16:35 2007, tobin, Update, PSL, ISS
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I was confused to find that I could increase the ISS gain slider all the way from 15dB to 30dB without seeing much of any increase in gain in the measured
open-loop transfer function. While making these swept-sine measurements, the saturation indicator almost never tripped, indicating it was seemingly happy.
But then I noticed an odd thing: if I disable the test ("analog excitation") input, the saturation indicator trips immediately. I hooked up a scope to |