ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
11856
|
Mon Dec 7 10:45:21 2015 |
ericq | Update | CDS | daqd is mad | Since removing c1pem from the daqd master
file, daqd has not crashed. I suppose we're
running into the stability issue that motivated |
|
11862
|
Tue Dec 8 15:18:29 2015 |
ericq | Update | Computer Scripts / Programs | Nodus security | I've done a couple things to try and
make nodus a little more secure. Some have
worried that nodus may be susceptible to |
|
11880
|
Mon Dec 14 16:46:42 2015 |
ericq | Update | WienerFiltering | Noise Subtraction Puzzler | Here's something to ponder.
Our online MCL feedforward uses
perpendicular vertex T240 seismometer signals |
|
11881
|
Mon Dec 14 23:49:03 2015 |
ericq | Update | Optical Levers | Calibration of oplevs for ITMX/ETMX |
|
|
11882
|
Mon Dec 14 23:56:29 2015 |
ericq | Update | CDS | c1pem reverted | To get C1PEM data back into the frames,
I removed the new BLRMS blocks, recompiled,
reinstalled, re-enabled it in daqd, restarted. |
|
11888
|
Wed Dec 16 23:15:28 2015 |
ericq | Update | Green Locking | Green beat channels temporarily set up as IR beat channels | With the IR beats going to the nominal
ALS channels as Gautam left them, we're
able to measure the free running frequency |
|
11889
|
Thu Dec 17 01:55:16 2015 |
ericq | Update | LSC | Uncooperative AUX X | [ericq, Gautam]
We were not able to fix the excess
frequency noise of the AUX X laser by the |
|
11893
|
Sun Dec 20 23:23:54 2015 |
ericq | Update | ALARM | Rats. | A small rat / large mouse just ran through
the control room. Ugh. |
|
11894
|
Mon Dec 21 02:29:49 2015 |
ericq | Update | LSC | AUX X RIN measurements | I'll finish up the beat / frequency
noise parts of the diagnosis tomorrow
later, but I've done some investigation |
|
11908
|
Tue Jan 5 02:54:38 2016 |
ericq | Update | LSC | AUX X Freq Noise attempt | [ericq, Gautam]
We set out to lock a marconi to
the IR fiber beat of PSL + AUX X to measure |
|
11912
|
Tue Jan 5 16:33:45 2016 |
ericq | Update | LSC | AUX X Freq Noise attempt | Turning on the MCL path (in addition to
the MCL FF we always have on) let me lock
the PLL for multiple seconds, but low frequency |
|
11916
|
Wed Jan 6 16:40:49 2016 |
ericq | Update | General | New WiFi router | The new wifi router, a Netgear R6400,
has been installed, next to the old one which
is disconnected (but not yet removed). |
|
11917
|
Thu Jan 7 04:28:39 2016 |
ericq | Update | LSC | AUX X Freq Noise measured | [ericq, Gautam]
Brief summary of tonights work:
Locked Marconi to AUX X |
 |
11918
|
Thu Jan 7 15:29:54 2016 |
ericq | Update | WienerFiltering | Noise Subtraction Puzzler | The puzzle continues...
I found some reference for computing
"multicoherence," which should |
 |
11919
|
Thu Jan 7 16:52:32 2016 |
ericq | Update | LSC | AUX X Freq Noise measured | Here is some of the promised data. As mentioned,
changing diode current and crystal temperature
didn't have much effect on the frequency |
 |
11921
|
Fri Jan 8 14:47:33 2016 |
ericq | Update | LSC | AUX Y Freq Noise measured | Here are some results from measuring the
PSL / AUX Y beat.
With the Y end laser, I was able |
 |
11931
|
Thu Jan 14 02:33:37 2016 |
ericq | Update | LSC | ALSX Noise still anomalously high | [ericq, Gautam]
We checked the UGF of the AUX X
PDH servo, found a ~6kHz UGF with ~45 degree |
 |
11933
|
Thu Jan 14 15:08:37 2016 |
ericq | Update | WienerFiltering | Noise Subtraction Puzzler | The anticlimatic resolution to my subtraction
confusion: Spectral leakage around 1Hz. Increasing the
FFT length to 256 sec now shows that the |
|
11938
|
Wed Jan 20 02:53:18 2016 |
ericq | Update | LSC | Hopeful signs | [ericq, Gautam]
We gave DRFPMI locking a shot,
with the ALS out-of-loop noises as attached. |
|
11943
|
Fri Jan 22 01:56:01 2016 |
ericq | Update | LSC | Audio ALSX | I hooked up the ALSX DFD output to the
fibox, and used the adjustable delay line
to set the phase properly. I recorded the |
|
11945
|
Fri Jan 22 13:33:37 2016 |
ericq | Update | Green Locking | AUX-X AM/PM investigations |
|
|
11957
|
Thu Jan 28 14:54:49 2016 |
ericq | Update | LSC | Status of the green PDH circuits | Yesterday, I uploaded some EAGLE schematic
files and a LISO source file for the green
PDH servo electronics to the 40m LISO git |
|
11982
|
Tue Feb 9 04:37:10 2016 |
ericq | Update | Green Locking | Laser swap initiated | [ericq, Gautam]
Tonight we embarked on the laser
swap. In short, we have gotten ~210mW through |
|
11993
|
Tue Feb 16 15:02:19 2016 |
ericq | Update | General | Power Glitch recovery | Chiara reports an uptime of >195 days,
so its UPS is working fine |
|
11997
|
Wed Feb 17 13:45:15 2016 |
ericq | Update | General | No monit on frontends | daqd has indeed continued to be unstable.
I found system times had drifted apart again...
I think something weird happened in the booting |
|
11998
|
Thu Feb 18 02:52:27 2016 |
ericq | Update | IOO | Some housekeeping | I manually aligned the IMC. Spot positions
are all < 1.5mm. PMC trans of ~0.74, MC2
Trans of ~15400, MC Refl ~0.4, which is better |
|
12003
|
Mon Feb 22 23:00:21 2016 |
ericq | Update | SUS | ITMX free, green is flashing | Taking
inspiration from |
|
12021
|
Fri Mar 4 13:52:41 2016 |
ericq | Update | IOO | PSL Laser Opened | PSL Table doors were open, and the laser
shutter was closed.
Doors have been closed, laser has |
|
12025
|
Mon Mar 7 20:40:02 2016 |
ericq | Update | CDS | FB down again | We went and looked at the monitor plugged
into FB. All kinds of messages were
being spammed to the screen (maybe RAM errors), |
|
12028
|
Thu Mar 10 03:03:11 2016 |
ericq | Update | LSC | DRFPMI Power stable, but no RF handoff | [ericq, Gautam]
We worked on getting the DRFPMI
back up and running, hoping the ALS performance |
|
12053
|
Tue Mar 29 03:16:21 2016 |
ericq | Update | LSC | DRFPMI Locked Once More | [ericq, Gautam]
Three RF-only locks longer than
a minute tonight, out of 5 total attempts. |
  |
12055
|
Wed Mar 30 16:40:24 2016 |
ericq | Update | LSC | 2016 vs 2010 | I haven't found any data files for
the DARM spectrum of the previous generation
of 40m, but with some GIMP-fu, I have plotted |
|
12059
|
Fri Apr 1 13:11:26 2016 |
ericq | Update | WienerFiltering | Bilinear Noise Testing | I've been banging my head against bilinear
noise subtraction, and figured I needed to
test things on some real hardware to see |
 |
12069
|
Mon Apr 11 16:06:30 2016 |
ericq | Update | LSC | DRFPMI Data Archived | I have copied over the complete frame files
from two DRFPMI lock acquisitions + locks to
/frames/archive |
|
12076
|
Thu Apr 14 17:30:18 2016 |
ericq | Update | General | PLL measurement ongoing | Just a heads up that some equipment is
hooked up at the PSL table for the repaired
AUX laser PLL measurement, I plan to continue |
|
12077
|
Fri Apr 15 03:02:44 2016 |
ericq | Update | General | New AUX laser measurements | The free running PSL+AUX beat frequency
noise spectrum has been measured via PLL.
AUX laser PZT PM and AM responses were measured |
  |
12097
|
Thu Apr 28 15:23:11 2016 |
ericq | Update | LSC | Green PDH demod lowpass | The 2F product out of the mixer is a natural
concern when demodulating. However, I think
this isn't so big of a deal in our green |
|
12101
|
Fri Apr 29 16:13:36 2016 |
ericq | Update | LSC | Green PDH demod lowpass | We can get
as much, if not more, attenuation of the
1F line in the mixer output that we get from |
  |
12106
|
Thu May 5 04:05:03 2016 |
ericq | Update | LSC | Aux X PDH checks | We took an OLG measurement of the green
PDH loop. It seems consistent with past measurements.
I've added a trace for the the post-mixer |
 |
12107
|
Thu May 5 14:03:52 2016 |
ericq | Update | LSC | Further Aux X PDH tweaks | This morning I poked around with the green
layout a bit. I found that the iris immediately
preceding the viewport was clipping the ingoing |
|
12110
|
Fri May 6 16:42:12 2016 |
ericq | Update | LSC | Green PDH demod lowpass | I've build the filter, and it seems
to have the desired TF shape.
|
 |
12112
|
Sat May 7 09:40:40 2016 |
ericq | Update | LSC | Green PDH demod lowpass | As I was looking at filter designs, it
seemed difficult to get 40dB of supression
at 2F with a bandpass without going to a |
|
12114
|
Tue May 10 03:44:59 2016 |
ericq | Update | LSC | Relocked | ALSX noise is solidly within past acceptable
performance levels. The DRFPMI was locked
on four out of six attempts. |
|
12115
|
Wed May 11 16:39:01 2016 |
ericq | Update | VAC | c0rga alive, output wonky |
|
|
12128
|
Tue May 24 10:21:36 2016 |
ericq | Summary | SUS | ITMX Oplev loops | I did a quick measurement of the ITMX oplev
loops, both pitch and yaw have about the
same upper UGF as previous measurements with |
|
12131
|
Tue May 24 23:17:37 2016 |
ericq | Update | COC | Finesse modelling - mode overlap scans | I think you should use the current actual
PRC & SRC cavity lengths as measured,
as it would be simplest to simply replace |
|
12132
|
Wed May 25 02:54:09 2016 |
ericq | Update | General | Odds and ends | WFS locking point seemed degraded; I hand
aligned and reset the WFS offsets as usual.
ITMX oplev recentered. While doing |
|
12138
|
Fri May 27 02:52:53 2016 |
ericq | Update | LSC | Restoring high BW single arm control | I've been futzing with the common mode
servo, trying to engage the AO path with
POY for high bandwidth control of a single |
|
12145
|
Wed Jun 1 16:28:28 2016 |
ericq | Update | Electronics | Common board Op amp input offsets | I used a Eurocard extension board to peek
at the inputs and outputs of each of the
gain-ladder AD829s on input B of the CM board |
|
12147
|
Fri Jun 3 12:53:44 2016 |
ericq | Update | Electronics | Common board Op amp input offsets | I replaced some of the AD829s with other
AD829s, but the offset situation didn't
improve. |
|