ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
13204
|
Mon Aug 14 16:24:09 2017 |
gautam | Update | ALS | Fiber ALS | Today, I borrowed the fiber microscope
from Johannes and took a look at the fibers
coupled to the PDs. The PD labelled " |
   |
13222
|
Wed Aug 16 20:24:23 2017 |
gautam | Update | ALS | Fiber ALS | Today, with Johannes' help, I cleaned
the fiber tips of the photodiodes. The effect
of the cleaning was dramatic - see Attachments |
   |
13229
|
Fri Aug 18 23:59:53 2017 |
gautam | Update | ALS | X Arm ALS lock | [ericq, gautam]
I was just getting the
IFO aligned, and single arm lock going, when |
|
13230
|
Sat Aug 19 01:35:08 2017 |
ericq | Update | ALS | X Arm ALS lock | My motivation tonight was to get an up-to-date
spectrum of a calibrated measurement
of the out-of-loop displacement of an arm |
|
13237
|
Mon Aug 21 23:38:55 2017 |
gautam | Update | ALS | ALS out-of-loop noise | I worked a little bit on the Y arm ALS
today.
Started by locking the |
|
13238
|
Tue Aug 22 02:19:11 2017 |
gautam | Update | ALS | ALS OLTFs | Attachment #1 shows the
results of my measurements tonight (SR785
data in Attachment #2). |
 |
13244
|
Tue Aug 22 23:27:14 2017 |
rana | Update | ALS | ALS OLTFs | Didn't someone look at what the OLG
req. should be for these servos at some point?
I wonder if we can make a parallel digital |
|
13246
|
Wed Aug 23 17:22:36 2017 |
gautam | Update | ALS | Fiber ALS - reinstalled | I completed the revamp of the box, and
re-installed the box on the PSL table today.
I think it would be ideal to install this |
|
13254
|
Fri Aug 25 15:54:14 2017 |
gautam | Update | ALS | Fiber ALS noise measurement | [Kira, gautam]
Attachment #1 - Photo
of the revamped beat setup. The top panel |
  |
13255
|
Fri Aug 25 17:11:07 2017 |
rana | Update | ALS | Fiber ALS noise measurement | Is it better to mount the box in the PSL
under the existing shelf, or in a nearby
PSL rack? |
|
13257
|
Sun Aug 27 11:57:31 2017 |
rana | Update | ALS | Fiber ALS noise measurement | It seems like the main contribution to
the RMS comes from the high frequency bump.
When using the ALS loop to lock the arm to |
|
13266
|
Tue Aug 29 02:08:39 2017 |
gautam | Update | ALS | Fiber ALS noise measurement | I was having a chat with EricQ about this
today, just noting some points from our discussion
down here so that I remember to look into |
|
13288
|
Fri Sep 1 19:15:40 2017 |
gautam | Update | ALS | Fiber ALS noise measurement | Summary:
I
did some work today to see if I could use |
|
13325
|
Thu Sep 21 01:32:00 2017 |
gautam | Update | ALS | AUX X Innolight AM measurement running | [rana,gautam]
We set up a measurement of the
AUX X laser AM today. Some notes: |
   |
13326
|
Thu Sep 21 01:55:16 2017 |
rana | Update | ALS | X End table of Shame | Image #1: No - we do not use magnetic mounts
for beam dumps. Use a real clamp. It has
to be rigid. "its not going anywhere" |
   |
13327
|
Thu Sep 21 15:23:04 2017 |
gautam | Omnistructure | ALS | Long cable from LSC->IOO | [steve,gautam]
We laid out a 45m long BNC cable
from the LSC rack to the IOO rack via overhead |
|
13333
|
Tue Sep 26 19:10:13 2017 |
gautam | Update | ALS | Fiber ALS setup neatened | [steve, gautam]
The Fiber ALS box has been installed
on the existing shelf on the PSL table. We |
|
13335
|
Wed Sep 27 00:20:19 2017 |
gautam | Update | ALS | More AM sweeps | Attachment #1: Result
of AM sweeps with EX laser crystal at nominal
operating temperature ~ 31.75 C. |
   |
13337
|
Wed Sep 27 23:44:45 2017 |
gautam | Update | ALS | Proposed PM measurement setup | Attachment #1 is
a sketch of the proposed setup to measure
the PM response of the EX NPRO. Previously, |
|
13346
|
Fri Sep 29 11:16:52 2017 |
Steve | Update | ALS | Y End table corrected | The first Faraday isolater rejected beam
path from the NPRO is fixed.
|
|
13366
|
Fri Oct 6 17:08:09 2017 |
Steve | Update | ALS | X End table beam traps corrected | There are no more double sided tape on
this table.
|
   |
13502
|
Thu Jan 4 12:46:27 2018 |
gautam | Update | ALS | Fiber ALS assay | Attachment
#1 is the updated |
 |
13519
|
Tue Jan 9 21:38:00 2018 |
gautam | Update | ALS | ALS recovery |
Aligned IFO to IR.
Ran
dither alignment to maximize arm transmission.
Centered
Oplev reflections onto their respective QPDs |
  |
13531
|
Thu Jan 11 14:22:40 2018 |
gautam | Update | ALS | Fiber ALS assay | I did a cursory check of the ALS signal
chain in preparation for commissioning the
IR ALS system. The main elements of this |
|
13534
|
Thu Jan 11 20:51:20 2018 |
gautam | Update | ALS | Fiber ALS assay | After labeling cables I would disconnect,
I pulled the box out of the LSC rack. Attachment
#1 is a picture of the insides of the box |
|
13552
|
Tue Jan 16 21:50:53 2018 |
gautam | Update | ALS | Fiber ALS assay | With Johannes' help, I re-installed
the box in the LSC electronics rack. In the
end, I couldn't find a good solution |
|
13557
|
Thu Jan 18 00:35:00 2018 |
gautam | Update | ALS | Fiber ALS assay | Summary:
I
am facing two problems: |
 |
13559
|
Fri Jan 19 11:34:21 2018 |
gautam | Update | ALS | Fiber ALS assay | I swapped the inputs to the ZHL-3A at the
PSL table - so now the X beat RF signals
from the beat mouth are going through what |
|
13562
|
Fri Jan 19 23:04:11 2018 |
gautam | Update | ALS | Fiber ALS assay | [rana, kevin, udit, gautam]
quick notes of some discussions
we had today: |
|
13571
|
Wed Jan 24 00:33:31 2018 |
gautam | Update | ALS | Fiber ALS assay | I did some work on the PSL table today.
Main |
|
13573
|
Wed Jan 24 00:58:59 2018 |
gautam | Update | ALS | X Green PDH modulation depth | On Friday, while Udit and I were doing
some characterization of the EX+PSL IR beat
at the LSC rack, I noticed that there were |
|
13574
|
Wed Jan 24 10:45:14 2018 |
gautam | Update | ALS | Fiber ALS assay | I was looking into the physics of polarization
maintaining fibers, and then I was trying
to remember whether the fibers we use are |
|
13583
|
Thu Jan 25 13:18:41 2018 |
gautam | Update | ALS | Fiber ALS assay | I was looking at this a little more closely.
As I understand it, the purpose of the audio
differential IF amplifier is: |
|
13586
|
Thu Jan 25 23:59:14 2018 |
gautam | Update | ALS | Fiber ALS assay | I tried to couple the PSL pickoff into
the fiber today for several hours, but got
nowhere really, achieved a maximum coupling |
|
13587
|
Fri Jan 26 20:03:09 2018 |
gautam | Update | ALS | Fiber ALS assay | I think part of the problem was that the
rejected beam from the PBS was not really
very Gaussian - looking at the spot on the |
|
13591
|
Wed Jan 31 15:45:22 2018 |
gautam | Update | ALS | Fiber ALS assay | Attachment #1 shows the current situation
of the PSL table IR pickoff. It isn't
the greatest photo but it's hard to get |
|
13593
|
Wed Jan 31 16:29:42 2018 |
gautam | Update | ALS | Modulation depths | I used the Beat
Mouth to make a quick |
 |
13594
|
Wed Jan 31 16:33:53 2018 |
gautam | Update | ALS | ALS electronics at LSC rack | [steve,
gautam]
We installed some |
|
13595
|
Wed Jan 31 22:32:11 2018 |
gautam | Update | ALS | ALS signal chain + power budget | Summary:
|
 |
13596
|
Thu Feb 1 01:24:56 2018 |
gautam | Update | ALS | D0902745 revamp underway | I effected the change to the Audio IF preamp
stage on channels 3 and 4 (Xarm and Yarm
respectively) using the resistors Steve ordered |
|
13597
|
Thu Feb 1 15:31:12 2018 |
gautam | Update | ALS | ALS signal chain + power budget | Summary:
A |
|
13599
|
Fri Feb 2 00:26:34 2018 |
gautam | Update | ALS | D0902745 revamp underway | I saw some interesting behaviour of the
Audio IF amplifier stage on the demod board
today, by accident. I was testing the board |
|
13600
|
Fri Feb 2 13:16:55 2018 |
gautam | Update | ALS | ALS signals whitening switching | While setting up for this measurement,
I noticed something odd with the whitening
switching for the ALS channels. For the usual |
 |
13606
|
Mon Feb 5 14:11:01 2018 |
gautam | Update | ALS | Huge harmonics in ALS channels | I've been trying to setup for the THD
measuremetn at the LSC rack for a couple
of days now, but am plagued by a problem |
 |
13608
|
Mon Feb 5 22:57:28 2018 |
gautam | Update | ALS | Huge harmonics in ALS channels | Did some quick additional checks to figure
out what's going on here.
The SOS/dewhite board for |
|
13609
|
Tue Feb 6 11:13:26 2018 |
gautam | Update | ALS | Possible source of ground loop identified | I think I've narrowed down the source
of this ground loop. |
|
13612
|
Tue Feb 6 22:55:51 2018 |
gautam | Update | ALS | Possible source of ground loop identified | [koji, gautam]
We discussed possible solutions |
|
13613
|
Wed Feb 7 10:16:26 2018 |
gautam | Update | ALS | ALS signal chain + power budget | After emailing the technical team at Menlo,
I have uploaded the more detailed information
they have given me on our wiki. |
|
13616
|
Wed Feb 7 15:51:15 2018 |
gautam | Update | ALS | D0902745 revamp complete | Summary of my tests of the demod boards,
post gain modification:
DC tests (supply voltage, |
|
13621
|
Thu Feb 8 00:33:20 2018 |
gautam | Update | ALS | D990694 characterization / THD measurement plan | I decided to try doing the THD measurement
with a function generator. Did some quick
trials tonight to verify that the measurement |
|