ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
9832
|
Fri Apr 18 20:17:17 2014 |
Jenne | Update | LSC | ALS noisy | Last night, as well as tonight, the ALS
seems not quite as robust as it was earlier
in the week. |
 |
15046
|
Mon Nov 25 19:11:22 2019 |
gautam | Update | LSC | ALS noise re-look | I re-checked the ALS noise in the following
configurations:
PRM is misaligned.
Michelson |
|
15233
|
Thu Feb 27 22:45:40 2020 |
gautam | Update | ALS | ALS noise high | There was some UNELOGGED work at EX today.
The DFD outputs were also hijacked for loss
measurement. Unclear |
|
15617
|
Wed Oct 7 16:56:23 2020 |
anchal | Summary | ALS | ALS noise budget update - Updated AUX PDH Loop values | AUX PDH Loop update
I
used D1400293
to get the latest logged details about the |
 |
15619
|
Thu Oct 8 11:59:52 2020 |
rana | Summary | ALS | ALS noise budget update - Updated AUX PDH Loop values | For all the loops where we drive the NPRO
PZT, there is some notch/resonance feature
due to the PZT mechanical resonance. In the |
|
15622
|
Fri Oct 9 18:32:14 2020 |
anchal | Summary | ALS | ALS noise budget update - Updated AUX PDH Loop values | The only two PZT Phase modulation transfer
function measurements I could find are 40m/15206 |
|
15626
|
Wed Oct 14 17:03:55 2020 |
anchal | Summary | ALS | ALS noise budget update - Added whitening filter for ADC | Koji recommended that I can add whitening
filters to suppress ADC noise easily. I added
a filter before ADC in ALS loop with 4 zeros |
|
15587
|
Sat Sep 19 23:59:22 2020 |
anchal | Summary | ALS | ALS noise budget update | Setting the record straight
I
found out an error I did in copying some
control model values from Kiwamu's matlab |
    |
15589
|
Sun Sep 20 23:12:13 2020 |
rana | Summary | ALS | ALS noise budget update | I think the digital loop in the ALS budget
is too optimistic. You have to include all
the digital delays and anti-aliasing filters |
|
15593
|
Tue Sep 22 00:14:43 2020 |
anchal | Summary | ALS | ALS noise budget update | This is not a reply to comments
given to the last post; Still working on
incorporating those suggestions. |
 |
15594
|
Tue Sep 22 12:14:42 2020 |
rana | Summary | ALS | ALS noise budget update | This ALS loop is not stable. Its one of
those traps that comes from using only the
Bode plot to estimate the loop stability. |
|
15601
|
Wed Sep 23 11:13:49 2020 |
anchal | Summary | ALS | ALS noise budget update | Yes, that loop was unstable. I started
using the time domain response to check for
the stability of loops now. I have been able |
 |
10884
|
Fri Jan 9 14:13:02 2015 |
manasa | Update | General | ALS noise at ~30Hz | Before starting to move things around the
PSL table, I measured the ALS out of loop noise |
 |
9836
|
Mon Apr 21 22:53:16 2014 |
manasa | Update | LSC | ALS noise |
|
 |
8738
|
Mon Jun 24 16:06:17 2013 |
Manasa | Summary | Green Locking | ALS model | I am working on the basic
ALS servo model. The simulink model for the
same is attached. The loop is not yet complete |
|
8659
|
Thu May 30 18:29:21 2013 |
Manasa | Update | General | ALS medm screens edited | Renaming of the c1gcv model earlier (elog
7011) had left white boxes in most of |
|
9649
|
Tue Feb 18 23:55:33 2014 |
Jenne | Update | LSC | ALS locked with LSC! | I'm really excited, so I'm posting this,
even though I'm still working:
|
|
9650
|
Wed Feb 19 00:35:23 2014 |
Koji | Update | LSC | ALS locked with LSC! | Great. I indeed disabled all of the triggers
and the normalization during my trial but
in vain. |
|
9651
|
Wed Feb 19 01:33:03 2014 |
Jenne | Update | LSC | ALS locked with LSC! | I am also not able to lock the ALS using
the 'regular' LSC filters. To figure
out what filters were doing what, I made |
  |
9652
|
Wed Feb 19 03:07:22 2014 |
Jenne | Update | LSC | ALS locked with LSC! | No more progress tonight.
I am still unable to lock the ALS using the
regular LSC filters. I went back to |
|
9659
|
Wed Feb 19 22:47:26 2014 |
Jenne | Update | LSC | ALS locked using LSC model, Common & Diff transitioned to IR transmission signals | [Jenne, Koji, Manasa, EricQ]
Today
we successfully locked the ALS using the |
 |
10925
|
Tue Jan 20 20:03:17 2015 |
Jenne | Update | LSC | ALS lock not staying? | The Xarm ALS has been a little funky today.
First, the green and the arm-axis
would not stay co-aligned. I'm |
|
10335
|
Wed Aug 6 00:14:10 2014 |
Jenne | Update | LSC | ALS is iffy tonight | The ALS system is iffy tonight.
After putting the cable back to the
RF spectrum analyzer (it had been taken to |
|
10399
|
Fri Aug 15 02:05:55 2014 |
Jenne | Update | LSC | ALS in-loop spectra | Not sure why, but Rana and I didn't
see the super high Xarm noise with ALS that
we reported last night (elog |
|
9195
|
Thu Oct 3 09:01:06 2013 |
manasa | Update | Green Locking | ALS high frequency noise | As I was trying to solve the 2 arm
ALS problem, I found the Y arm ALS not so
stable AGAIN :( . I measured the in-loop |
|
8694
|
Tue Jun 11 22:16:56 2013 |
Manasa | Summary | Green Locking | ALS for X arm | I discussed with Yuta about the ALS servo
and phase tracker and found that there was
a lot of information lying around from last |
|
11037
|
Mon Feb 16 02:49:57 2015 |
Jenne | Update | LSC | ALS fool measured decoupling TF | I have measured very, very carefully the
transfer function from pushing on
MC2 to the Yarm ALS beatnote. |
 |
11038
|
Mon Feb 16 03:10:42 2015 |
Koji | Update | LSC | ALS fool measured decoupling TF | Wonkey shape: Looks like a loop supression.
Your http://nodus.ligo.caltech.edu:8080/40m/11016
also suggests it too, doesn't it? |
|
11039
|
Mon Feb 16 15:08:26 2015 |
Jenne | Update | LSC | ALS fool measured decoupling TF | Dang it, yes. You're right. I
should have caught that.
Since Dcpl and Srefl are both zero |
|
11042
|
Tue Feb 17 04:04:32 2015 |
Jenne | Update | LSC | ALS fool math | I re-did the Mathematica notebook according
to the most current diagram (note to daytime
self: attach .nb file!!!), and found that |
 |
11043
|
Tue Feb 17 16:36:08 2015 |
Jenne | Update | LSC | ALS fool math | Here is an updated cartoon, with the ALS
sensor explicitly shown as the beatbox times
the closed loop response of the phase tracker |
 |
11030
|
Sat Feb 14 20:20:24 2015 |
Jenne | Update | LSC | ALS fool cartoon | The ALS fool scheme is now diagrammed up
in OmniGraffle, including its new official
icon. The mathematica notebook has |
 |
11050
|
Thu Feb 19 04:16:45 2015 |
Jenne | Update | LSC | ALS fool attempt with PRFPMI | [Jenne, EricQ]
We tried several times tonight
to engage the Fool path with the PRFPMI. |
 |
5888
|
Mon Nov 14 17:01:14 2011 |
kiwamu | Update | Green Locking | ALS feedback on MC2 | Leaving a note on the ALS feedback before
I forget:
The |
|
6154
|
Wed Dec 28 14:13:16 2011 |
kiwamu | Update | Green Locking | ALS feedback on MC2 | I
added an ALS feedback path on the MC2 suspension
and this path will enable us to stabilise |
|
14993
|
Fri Oct 25 01:04:49 2019 |
gautam | Update | ALS | ALS electronics chain was saturating | [Koji, gautam]
Summary:
We think we got to the bottom of |
|
13594
|
Wed Jan 31 16:33:53 2018 |
gautam | Update | ALS | ALS electronics at LSC rack | [steve,
gautam]
We installed some |
|
9226
|
Wed Oct 9 18:45:17 2013 |
Masayuki | Update | Green Locking | ALS down script modified |
|
|
9204
|
Fri Oct 4 20:25:12 2013 |
Masayuki | Update | Green Locking | ALS down script | I wrote the down script for ALS. This script
is
(script)/ALS/ALSdown.py When |
|
14468
|
Wed Feb 20 23:55:51 2019 |
gautam | Update | ALS | ALS delay line electronics | Summary:
Last year, I worked
on the ALS delay line electronics, thinking |
|
14475
|
Thu Mar 7 01:06:38 2019 |
gautam | Update | ALS | ALS delay line electronics | Summary:
The restoration of the delay-line
electronics is complete. The chassis has |
|
14477
|
Tue Mar 12 22:51:25 2019 |
gautam | Update | ALS | ALS delay line electronics | This
Hanford alog may be of relevance as we
are using the aLIGO AA chassis for the IR |
|
14478
|
Wed Mar 13 01:27:30 2019 |
gautam | Update | ALS | ALS delay line electronics | This test was done, and I determine the
frequency discriminant to be |
 |
14479
|
Thu Mar 14 23:26:47 2019 |
Anjali | Update | ALS | ALS delay line electronics | Attachment #1 shows the schematic of the
test setup. Signal generator (Marconi) was
used to supply the RF input. We observed |
|
17384
|
Wed Jan 4 12:12:57 2023 |
Paco | Summary | Calibration | ALS calibration error from DFD | [Paco, Anchal]
One of the crucial and currently
limiting calibration errors is in the ALS |
|
6074
|
Tue Dec 6 00:26:00 2011 |
kiwamu | Update | LSC | ALS became robust : UGF = 100 Hz | Eventually
the instability in the Y end PDH servo turned
out to be some kind of an alignment issue. |
|
16956
|
Tue Jun 28 16:59:35 2022 |
Paco | Summary | ALS | ALS beat allan deviation (XARM) | [Paco]
I took ~ 7 minutes of XALS beatnote
data with the XAUX laser locked to the XARM |
 |
16959
|
Tue Jun 28 18:53:16 2022 |
rana | Summary | ALS | ALS beat allan deviation (XARM) | what's the reasoning behind using df/f_beat
instead of df/f_laser ?
|
|
16962
|
Wed Jun 29 14:28:06 2022 |
Paco | Summary | ALS | ALS beat allan deviation (XARM) | I guess it didn't make sense since
f_beat can be arbitrarily moved, but the
beat is taken around the PSL freq ~ 281.73 |
|
9178
|
Mon Sep 30 23:56:19 2013 |
manasa | Update | Green Locking | ALS autolocker flowchart | [Masayuki, Manasa]
Flowchart for ALS autolocker. The
error signal thresholds will be decided by |
|