 Thu Oct 11 13:40:51 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Quote:
This is the procedure I follow when I take these measurements for the XARM (symmetric under XARM <-> YARM):
Dither-align the interferometer with both arms locked. Freeze outputs when done.
Misalign ETMY + ITMY.
ITMY |
Fri Oct 12 08:27:05 2018, Steve, Update, VAC, drypump 
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Gautam and Steve,
Our TP3 drypump seal is at 360 mT [0.25A load on small turbo] after one year. We tried to swap in old spare drypump with new tip
seal. It was blowing it's fuse, so we could not do it. |
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Fri Oct 12 12:29:34 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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With Gautam's help, Y-arm was locked. Then I ran the script "armloss_dcrefl_asdcpd_scope.py" which gets the signals from oscilloscope.
It ran and got data, but I found some problems.
It seemed that a process which makes arm cavity mislaigned in the script didn't work.
The script "armloss_dcrefl_asdcpd_scope.py" |
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Fri Oct 12 17:37:03 2018, Steve, Update, VAC, pressure gauge choices
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We want to measure the pressure gradient in the 40m IFO
Our old MKS cold cathodes are out of order. The existing working gauge at the pumpspool
is InstruTech CCM501 |
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Fri Oct 12 20:20:29 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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I ran the script for measuring arm-loss and calculated rough Y-arm round trip loss temporally. The result was 89.6ppm. (The error should be considered
later.)
The measurement was done as follows: |
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Sat Oct 13 20:11:10 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Quote:
the script "armloss_AS_calc.py",
"ETM_YAW_L_DEMOD_I_OUTPUT" was little noisy even when the arm was locked.
The reflected beam power when |
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Sun Oct 14 16:55:15 2018, not gautam, Update, CDS, pianosa upgrade
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DASWG is not what we want to use for config; we should use the K. Thorne LLO
instructions, like I did for ROSSA.
Quote:
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Mon Oct 15 10:32:13 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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I used these values for measuring armloss:
Transmissivitity of ITM = 1.384e-2 * (1 +/- 1e-2)
Transmissivitity of ETM = 13.7e-6 * (1 +/- 5e-2)
Mode-Matching
efficiency of XARM = 0.912 * (1 +/- 2e-2)
Mode-Matching efficiency of YARM = 0.867 * (1 +/- 2e-2)
modulation depth m1 (11MHz) = 0.179 |
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Mon Oct 15 12:52:54 2018, yuki, Update, Computer Scripts / Programs, additional comments
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Quote:
but there's one weirdness: It get's the channel offset wrong. However
this doesn't matter in our measurement because we're subtracting the dark level, which sees the same (wrong) offset. |
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Mon Oct 15 13:59:42 2018, Steve, Update, VAC, drypump replaced
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Steve & Bob,
Bob removed the head cover from the housing to inspect the condition of the the tip seal. The tip seal was fine but the viton cover seal had
a bad hump. This misaligned the tip seal and it did not allow it to rotate. |
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Tue Oct 16 00:44:29 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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The scripts for measuring armloss are in the directory "/opt/rtcds/caltech/c1/scripts/lossmap_scripts/armloss_scope".
armloss_derefl_asdcpd_scope.py: gets data and makes ascii file.
armloss_AS_calc.py: calculates armloss from selected a set
of files.
armloss_calc_histogram.py: calculates armloss from selected files and makes histogram.
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 Wed Oct 17 09:31:24 2018, Steve, Update, PSL, main laser off
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| The main laser went off when PSL doors were opened-closed. It was turned back on and the PSL is locked. |
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Thu Oct 18 00:27:37 2018, Koji, Update, SUS, SUS PD Whitening board inspection
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[Gautam, Koji]
As a part of the preparation for the replacement of c1susaux with Acromag, I made inspection of the coil-osem transfer function measurements
for the vertex SUSs. |
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Mon Oct 22 15:19:05 2018, Steve, Update, VAC, Maglev controller serviced
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Gautam & Steve,
Our controller is back with Osaka maintenace completed. We swapped it in this morning.
Quote:
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Thu Oct 25 16:17:14 2018, Steve, Update, safety, safety training
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| Chub Osthelder received 40m specific basic safety traning today. |
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Wed Oct 31 17:54:25 2018, gautam, Update, VAC, CC1 hornet power connection restored
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Steve reported to me that the CC1 Hornet gauge was not reporting the IFO pressure after some cable tracing at EX. I found that the power to the unit
had been accidentally disconnected. I re-connected the power and manually turned on the HV on the CC gauge (perhaps this can be automated in the new vacuum
paradigm). IFO pressure of 8e-6 torr is being reported now. |
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Fri Nov 2 10:24:20 2018, Steve, Update, PEM, roof cleaning
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| Physical plan is cleaning our roof and gutters today. |
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Fri Nov 2 12:07:16 2018, rana, Update, CDS, NDScope
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https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=44971
Let's install Jamie's new Data Viewer |
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Fri Nov 2 16:42:31 2018, aaron, Update, Computer Scripts / Programs, arm loss measuremenents
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I'm continuing the arm loss measurements Yuki was making. I'm first familiarizing myself with the procedures for the measurement Johannes
describes.
I'm not very familiar with the medm screens, so I'm just kind of poking around and checking with Gautam. I do the following: |
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Fri Nov 2 19:25:16 2018, gautam, Update, Computer Scripts / Programs, loss measurements
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Some facts which should be considered when doing this measurement and the associated uncertainty:
When Johannes did the measurement, there was no light from the AS port diverted to the OMC. This represents ~70% loss in the absolute
amount of power available for this measurement. I estimate ~1W*Tprm * Ritm * Tbs * Rbs * Tsrm * OMCsplit ~ 300uW which should still be plenty, but the |
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Mon Nov 5 13:52:18 2018, aaron, Update, Computer Scripts / Programs, arm loss measuremenents
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After running this script Friday night, i noticed Saturday that the data hadn't saved. Scrolling up inthe terminal, I couldn't see where I'd
run the script, so I thought I'd forgotten to run it as I was making last minute changes to the scope settings Friday before leaving.
Monday it turns out I hadn't forgotten to run the script, but the script itself was getting hung up as it waited for ASS to settle, due to |
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Tue Nov 6 10:03:02 2018, Steve, Update, Electronics, Contec board found
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| The Contec test board with Dsub37Fs was on the top shelf of E7 |
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Tue Nov 6 10:19:26 2018, aaron, Update, Computer Scripts / Programs, arm loss measuremenents
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I'm checking out the data this morning, running armloss_AS_calc.py using the parameters Yuki
used here.
I made the following changes to scripts (measurement script and calculator script) |
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Tue Nov 6 15:23:48 2018, gautam, Update, IOO, IMC problematic
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The IMC has been misbehaving for the last 5 hours. Why?
I turned the WFS servos off. afaik, aaron was the last person to work on the IFO, so i'm not taking any further debugging steps so as to not disturb
his setup. |
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Tue Nov 6 15:32:24 2018, Steve, Update, PSL, MC_Transmitted
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I tried to plot a long trend MC Transmitted today. I could not get farther than 2017 Aug
4
Quote:
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Tue Nov 6 19:02:35 2018, aaron, Update, IOO, IMC problematic
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That was likely me. I had recentered the beam on the PD I'm using for the armloss measurements, and I probably moved the wrong steering mirror.
The transmission from MC2 is sent to a steering mirror that directs it to the MC2 transmission QPD; the transmission from this steering mirror I direct
to the armloss MC QPD (the second is what I was trying to adjust). |
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Tue Nov 6 23:19:06 2018, gautam, Update, VAC, c1vac1 FAIL lights on (briefly)
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Jon and I stuck a extender card into the eurocrate at 1X8 earlier today (~5pm PT), to see if the box was getting +24V DC from the Sorensen or not. Upon
sticking the card in, the FAIL LEDs
on all the VME cards came on. We immediately removed the extender card. Without any intervention from us, after |
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Wed Nov 7 05:16:16 2018, yuki, Update, Computer Scripts / Programs, arm loss measuremenents
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Please check your data file and compare with those Johannes made last year. I think the power in your data file may have only three-disits and flactuate
about 2%, which brings huge error. (see elog: 40m/14254)
Quote:
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Wed Nov 7 08:32:32 2018, Steve, Update, VAC, c1vac1 FAIL lights on (briefly)...checked
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The vacuum and MC are OK
Quote:
Jon and I stuck a extender card into the eurocrate at 1X8 earlier today (~5pm PT), to see if the box was getting |
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Wed Nov 7 19:20:53 2018, gautam, Update, Computers, Paola Battery Error
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The VEA vertex laptop, paola, has
a flashing orange indicator which I take to mean some kind of battery issue. When the laptop is disconnected from its AC power adaptor, it immediately
shuts down. So this machine is kind of useless for its intended purpose of being a portable computer we can work at optical tables with |
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Wed Nov 7 19:42:01 2018, gautam, Update, General, IFO checkup and DRMI locking prep
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Earlier today, I rebooted a few unresponsive VME crates (susaux, auxey).
The IMC has been unhappy for a couple of days - the glitches in the MC suspensions are more frequent. I reset the dark offsets, minimized MCREFL
by hand, and then re-centered the beam on the MC2 Trans QPD. In this config, the IMC has been relatively stable today, although judging by the control |
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Wed Nov 7 23:07:11 2018, gautam, Update, LSC, DRMI locking recovered
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I had some success today. I hope that the tweaks I made will allow working with the DRMI during the day as
well, though it looks like the main limiting factor in lock duty cycle is angular stability of the PRC.
Since there has been some change in the light levels / in vacuum optical paths, I decided to be a bit more systematic.
Initial |
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Fri Nov 9 15:00:56 2018, gautam, Update, IOO, No IFO beam as TT1 UL hijacked for REFL55 check
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This problem resurfaced. I'm doing the debugging.
6:30pm - "Solved" using the same procedure of stepping through the whitening gains with a small (10 DAC cts pk) signal applied. Simply
stepping through the gains with input grounded doesn't seem to do the trick. |
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Sat Nov 10 17:32:33 2018, gautam, Update, LSC, Nulling MICH->PRCL and MICH->SRCL
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With the DRMI locked, I drove a line in MICH using the sensing matrix infrastructure. Then I looked at the error points of MICH, PRCL and SRCL. Initially,
the sensing line oscillator output matrix for MICH was set to drive only the BS. Subsequently, I changed the --> PRM and --> SRM matrix elements
until the line height in the PRCL and SRCL error signals was minimized (i.e. the change to PRCL and SRCL due to the BS moving, which is a geometric effect, |
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Sat Nov 10 17:40:00 2018, aaron, Update, IOO, IMC problematic
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Gautam was doing some DRMI locking, so I replaced the photodiode at the AS port to begin loss measurements again.
I increased the resolution on the scope by selecting Average (512) mode. I was a bit confused by this, since Yuki was correct that I had only
4 digits recorded over ethernet, which made me think this was an i/o setting. However the sample acquisition setting was the only thing I could find on |
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Mon Nov 12 13:53:20 2018, rana, Update, IOO, loss measurement: oscope vs CDS DAQ
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sstop using the ssscope, and just put the ssssignal into the DAQ with sssssome whitening. You'll get 16 bitsśšß.
Quote:
I increased the resolution on the scope by selecting Average (512) mode. I was a bit confused by this, since Yuki |
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Tue Nov 13 16:15:01 2018, Steve, Update, VAC, rga scan pd81 at day 119
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Tue Nov 13 18:09:24 2018, gautam, Update, LSC, Investigation of SRCL-->MICH coupling
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Summary:
I've been looking into the cross-coupling from the SRCL loop control point to the Michelson error point.
[Attachment #1] - Swept sine measurement of transfer function |
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Tue Nov 13 21:53:19 2018, gautam, Update, CDS, RFM errors
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This problem resurfaced, which I noticed when I couldn't get the single arm locks going.
The fix was NOT restarting the c1rfm model, which just brought the misery of all vertex FEs crashing and the usual dance to get everything back.
Restarting the sender models (i.e. c1scx and c1scy) seems to have done the trick though. |
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Wed Nov 14 14:35:38 2018, Steve, Update, ALARM, emergency calling list for 40m Lab
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It is posted at the 40m wiki with Gautam' help. Printed copies posted around doors
also. |
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Wed Nov 14 18:58:35 2018, aaron, Update, DAQ, New DAC for the OMC
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I began moving the AA and AI chassis over to 1X1/1X2 as outlined in the elog.
The chassis were mostly filled with empty cables. There was one cable attached to the output of a QPD interface board, but there was nothing
attached to the input so it was clearly not in use and I disconnected it. |
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Thu Nov 15 10:21:07 2018, aaron, Update, IOO, IMC problematic
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I ran a BNC from the PD on the AS table along the cable rack to a free ADC channel on the LSC whitening board. I lay the BNC on top of the other cables
in the rack, so as not to disturb anything. I also was careful not to touch the other cables on the LSC whitening board when I plugged in my BNC. The PD
now reads out to... a mystery channel. The mystery channel goes then to c1lsc ADC0 channels 9-16 (since the BNC goes to input 8, it should be #16). To |
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Fri Nov 16 00:47:43 2018, gautam, Update, LSC, More DRMI characterization
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Summary:
More DRMI characterization was done.
I was working on trying to improve the stability of the DRMI locks as this is necessary
for any serious characterization.
Today I revived the PRC angular feedforward - this was a gamechanger, |
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Fri Nov 16 10:26:12 2018, Steve, Update, VAC, single viton O-rings
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The 40m vacuum envelope has one large single O-ring on the OOC west side. All other doors have double O-ring with annuloses.
There are 3 spacers to protect o-ring. They should not be removed!
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Fri Nov 16 10:53:07 2018, aaron, Update, IOO, IMC problematic
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Back to loss measurements.
I replaced the PD I've been using for the AS beam.
I misaligned the x arm. |
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Sat Nov 17 18:59:01 2018, aaron, Update, IOO, IMC problematic
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| I made additional measurements on the x and y arms, at 5 offset positions for each arm (along with 6 measurements at the "zeroed" position). |
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Sun Nov 18 00:59:33 2018, gautam, Update, General, Vent prep
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I've begun prepping the IFO for the vent, and completed most of the IFO related items on the checklist.
The power into the MC has been cut, but the low-power autolocker has not been checked. I will finish up tomorrow and post the go ahead. PSL shutter
is closed for tonight. |
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Sun Nov 18 17:09:02 2018, gautam, Update, General, Vent prep
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Vent prep
Following the checklist, I did these:
Both arms were locked to IR, TRY and TRX maximized using ASS.
GTRY and GTRX were also maximized.
ITM/ETM Oplevs |
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Mon Nov 19 14:59:48 2018, Chub, Update, VAC, Vent 81
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Vent 80 is nearly complete; the instrument is almost to atmosphere. All four ion pump gate valves have been disconnected, though the position sensors
are still connected,and all annulus valves are open. The controllers of TP1 and TP3 have been disconnected from AC power. VC1 and VC2 have been disconnected
and must remained closed. Currently, the RGA |
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Mon Nov 19 17:09:00 2018, Steve, Update, VAC, Vent 81
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Gautam, Aaron, Chub and Steve,
Quote:
Vent 80 is nearly complete; the instrument is almost to atmosphere. All four ion pump gate valves have been |