ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
14979
|
Fri Oct 18 20:21:33 2019 |
shruti | Update | ALS | AM measurement attempt at X end | [Shruti, Rana]
- At the X end, we set up the network
analyzer to begin measurement of the AM transfer |
|
14981
|
Mon Oct 21 12:25:46 2019 |
gautam | Update | ALS | DFD electronics checkout | Summary:
There are no unexpected red-flags
in the performance of the DFD electronics. |
   |
14984
|
Tue Oct 22 15:32:15 2019 |
gautam | Update | ALS | EX uPDH electronics checkout | Summary:
The EX PDH setup had what I thought
was insufficient phase and gain margins. |
|
14986
|
Wed Oct 23 10:23:26 2019 |
rana | Update | ALS | EX uPDH electronics checkout | During our EX AM/PM setups, I don't
think we bumped the PDH gain knob (and I
hope that the knob was locked). Possible |
|
14987
|
Wed Oct 23 11:11:01 2019 |
gautam | Update | ALS | EX uPDH electronics checkout | The closest thing I can think of is here.
|
|
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 |
|
14995
|
Mon Oct 28 23:20:11 2019 |
gautam | Update | ALS | ALS power budget |
IR |
|
15020
|
Thu Nov 7 17:46:10 2019 |
shruti | Update | ALS | AM measurement at X end | Some details:
- There
was a SR560+SR785 (not connected for measurement)
placed near the X end which I moved; it is |
|
15058
|
Mon Dec 2 00:27:20 2019 |
gautam | Update | ALS | Green ALS resurrection | Attachment
#1 - |
  |
15059
|
Mon Dec 2 18:20:29 2019 |
gautam | Update | ALS | EY uPDH post mixer LPF | As part of characterization, I wanted to
calibrate the EY uPDH error point monitor
into units of Hz. So I thought I'd measure |
 |
15060
|
Mon Dec 2 20:18:18 2019 |
rana | Update | ALS | EY uPDH post mixer LPF |
filter
Q seems too high, |
|
15063
|
Tue Dec 3 00:10:15 2019 |
Koji | Update | ALS | EY uPDH post mixer LPF | I got confused. Why don't we see that
too-high-Q pole in the OLTF? |
|
15064
|
Tue Dec 3 00:51:25 2019 |
gautam | Update | ALS | EY uPDH post mixer LPF | I'm not sure - maybe it was measurement
error on my part, I will double check. Moreover,
the EX |
|
15066
|
Tue Dec 3 18:15:42 2019 |
gautam | Update | ALS | EY uPDH post mixer LPF | Rana and I discussed this alogrythym a
bit today - here are some bullet points,
I'll work on preparing a notebook. We |
|
15068
|
Tue Dec 3 21:28:24 2019 |
gautam | Update | ALS | EY uPDH post mixer LPF | Here are some loop transfer functions.
I basically followed the decomposition of
the end PDH loop as was done in the multi-color |
|
15130
|
Fri Jan 17 18:02:21 2020 |
gautam | Update | ALS | Gain blocks packaged and characterized | Summary:
The ZHL-1010+
gain blocks acquired from MiniCircuits |
    |
15153
|
Fri Jan 24 17:14:01 2020 |
gautam | Update | ALS | Gain blocks installed | Jordan will write up the detailed elog
but in summary,
Former +24V Sorensen in |
|
15157
|
Sun Jan 26 14:40:55 2020 |
gautam | Update | ALS | ALS OOL noise | In preparation for resuming IFO locking
activities, I measured the ALS noise with
the arm lengths locked to IR, AUX laser frequencies |
|
15206
|
Tue Feb 11 16:39:00 2020 |
shruti | Update | ALS | AM/PM | The results of the AM/PM measurements:
Attachment 1: Traces
of 9 AM TFs overlaid on top of each other, |
    |
15209
|
Thu Feb 13 01:47:39 2020 |
gautam | Update | ALS | Fast ALS - delay line prep | A few years ago, Koji and I setup a delay
line phase shifter, which can be used to
impart a (switchable) delay to a signal path. |
  |
15211
|
Thu Feb 13 21:30:55 2020 |
shruti | Update | ALS | ALS OOL noise with arms locked | [Meenakshi, Gautam, Shruti]
Summary:
- We initially aligned the arm |
|
15212
|
Fri Feb 14 00:53:50 2020 |
gautam | Update | ALS | Fast ALS - more setup | In the process of setting up some cabling
at 1Y2, I must've bumped a cable to the
c1lsc expansion chassis. Anyways, the c1lsc |
 |
15213
|
Fri Feb 14 14:02:13 2020 |
shruti | Update | ALS | ALS OOL noise with arms locked | [Meenakshi, Shruti]
Even though we were not able to
lock the the IR beat (by enabling LSC) during |
  |
15214
|
Fri Feb 14 14:52:41 2020 |
gautam | Update | ALS | ALS OOL noise with arms locked | Unlikely, the alignment was probably just
not good. I restored the alignment and now
the arms can be locked to IR frequency. |
|
15216
|
Tue Feb 18 18:14:59 2020 |
shruti | Update | ALS | ALS OOL noise with arms locked | We proceeded with the trying to measure
the ALS out-of-loop noise of the X arm when
the X arm cavity is green-locked using different |
|
15217
|
Wed Feb 19 22:20:22 2020 |
rana | Update | ALS | ALS OOL noise with arms locked | Could you please put physical units on
the Y-axis and also put labels in the legend
which give a physical description of what |
|
15218
|
Fri Feb 21 10:59:08 2020 |
shruti | Update | ALS | PDH error signals? | |
   |
15219
|
Fri Feb 21 13:02:53 2020 |
Koji | Update | ALS | PDH error signals? | Check out this elog:
ELOG
4354 |
|
15220
|
Fri Feb 21 20:44:18 2020 |
shruti | Update | ALS | ALS OOL noise and PDH | [Meenakshi, Shruti]
In order to adjust the relative
phase for PDH locking, we used the Siglent |
 |
15221
|
Sun Feb 23 18:15:22 2020 |
rana | Update | ALS | ALS OOL noise and PDH | to
make the comparisons meaningfully |
|
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 |
|
15315
|
Fri May 1 01:49:55 2020 |
gautam | Update | ALS | ASY commissioning | Summary:
It appears that the EY green steering
PZTs have somehow lost their bipolar actuation |
|
15316
|
Fri May 1 22:44:17 2020 |
gautam | Update | ALS | ASY M2 PZT damaged | I went to EY and saw that the HV power
supply was only putting out 50 V and had
hit the current limit of 10 mA (nominally, |
|
15317
|
Sat May 2 02:35:18 2020 |
Koji | Update | ALS | ASY M2 PZT damaged | Yes, we are supposed to have a few spare
PI PZTs. |
|
15319
|
Wed May 6 00:31:09 2020 |
gautam | Update | ALS | Optomechanics during CARM offset reduction | Summary:
The apparent increase in the ALS
noise (witnessed in-loop, e.g. |
 |
15482
|
Wed Jul 15 17:46:05 2020 |
anchal | Summary | ALS | Noise budget for ALS | I started my attempt on noise budgeting
of ALS by going back to how Kiwamu did it
and adding as many sources as I could find |
|
15496
|
Mon Jul 20 19:21:16 2020 |
anchal | Summary | ALS | Few proposals for Voyager ALS | I've added 4
proposed schemes for implementing ALS
in voyager. Major thing to figure out is |
|
15531
|
Mon Aug 17 23:36:10 2020 |
gautam | Update | ALS | Whitening and ALS noise | I finally managed to
install a differential-receiving whitening
board in 1Y2 - 4 channels are available at |
|
15533
|
Tue Aug 18 13:55:23 2020 |
rana | Update | ALS | Whitening and ALS noise | No, there should be no unscheduled visits
from any inspector, marshal, tech, or vendor.
They all have to be escorted or they don't |
|
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 |
 |
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 |
|
15751
|
Wed Jan 6 22:47:41 2021 |
gautam | Update | ALS | Noisy ALS | Summary:
I want to get back to locking the
interferometer so I can test out the newly |
 |
15752
|
Thu Jan 7 19:16:11 2021 |
gautam | Update | ALS | Noisy ALS | I'm also wondering why the error monitors
for the X and Y loops report such wildly
different spectra for the suppressed frequency |
 |