| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
15739
|
Sat Dec 19 00:25:20 2020 |
Jon | Update | | New SMA cables on order | I re-ordered the below cables, this
time going with flexible, double-shielded
RG316-DS. |
|
|
15740
|
Sat Dec 19 02:42:56 2020 |
Koji | Update | | New SMA cables on order | Our favorite (flexible) RF cable is Belden's
1671J (Jacketed solder-soaked coax cable).
It is compatible RG405. I'm not sure |
|
|
15741
|
Sat Dec 19 20:24:25 2020 |
gautam | Update | Electronics | WFS hardware install | I installed 4 chassis in the rack 1X2 (characterization
on the E-bench was deemed satisfactory, I
will upload the analysis later). I ran out |
|
|
15743
|
Mon Dec 21 18:18:03 2020 |
gautam | Update | CDS | Many model changes | The CDS model change required to get the
AS WFS signals into the RTCDS system are
rather invasive. |
|
|
15744
|
Tue Dec 22 22:11:37 2020 |
gautam | Update | CDS | AA filt repaired and reinstalled | Koji fixed the problematic channel - the
issue was a bad solder joint on the input
resistors to the THS4131. The board was re-installed. |
|
|
15745
|
Wed Dec 23 10:13:08 2020 |
gautam | Update | CDS | Near term upgrades | Summary:
There appears to be insufficient |
|
|
15747
|
Sun Jan 3 16:26:06 2021 |
Koji | Update | SUS | IMC WFS check (Yet another round of Sat. Box. switcharoo) | I wanted to check the functionality of
the IMC WFS. I just turned on the WFS servo
loops as they were. For the past two hours, |
|
|
15748
|
Wed Jan 6 15:28:04 2021 |
gautam | Update | VAC | Vac rack UPS batteries replaced | [chub, gautam]
the replacement was done this afternoon.
The red "Replace Battery" indicator |
|
|
15749
|
Wed Jan 6 16:18:38 2021 |
gautam | Update | Optical Levers | BS Oplev glitchy | As part of the hunt why the X
arm IR transmission RIN is anomalously high,
I noticed that the BS Oplev Servo periodically |
|
|
15750
|
Wed Jan 6 19:00:04 2021 |
gautam | Update | LSC | Phase loss in POX/POY loops | I've noticed that there is some phase
loss in the POX/POY locking loops - see |
|
|
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 |
|
|
15753
|
Thu Jan 7 20:07:27 2021 |
Koji | Update | ALS | Noisy ALS | How about resurrecting the PSL table green
beat for the X arm to see if the non-fiber
setup shows the same level of the freq noise |
|
|
15754
|
Thu Jan 7 21:16:22 2021 |
gautam | Update | ALS | Noisy ALS | I thought about it, but wouldn't that
show up at the AUX PDH error point? Or because
the loop gain is so high there we wouldn't |
|
|
15755
|
Thu Jan 7 23:25:19 2021 |
Koji | Update | ALS | Noisy ALS | If the sensing noise level of the end PDH
degraded for some reason, it'd make the
out of loop stability worse without making |
|
|
15756
|
Fri Jan 8 20:01:11 2021 |
gautam | Update | ALS | Noisy ALS | I did this test today. The excess
noise around 100 Hz doesn't show up in
the green beat. |
|
|
15758
|
Mon Jan 11 16:11:51 2021 |
Yehonathan | Update | BHD | Monte Carlo loop coupling Simulations | I dived into the alog to make the OLTFs
in the MC_controls example more realistic.
I was mainly inspired by these entries: |
|
|
15759
|
Mon Jan 11 19:10:10 2021 |
rana | Update | BHD | Monte Carlo loop coupling Simulations |
looking better, but the CARM plot
still looks weird.
you should
plot from 0.01 - 10,000 Hz
All |
|
|
15763
|
Thu Jan 14 11:46:20 2021 |
gautam | Update | CDS | Expansion chassis from LHO | I picked the boxes up this morning. The
inventory per Fil's email looks accurate.
Some comments: |
|
|
15764
|
Thu Jan 14 12:19:43 2021 |
Jon | Update | CDS | Expansion chassis from LHO | That's fine, we didn't actually
request those. We bought and already have
in hand new PCIe x4 cables for the chassis-host |
|
|
15765
|
Thu Jan 14 12:32:28 2021 |
gautam | Update | CDS | Rogue master may be doing something good? | I think the "Rogue
Master" setting on the RFM network
may be doing some good. 5 mins, ago, all |
|
|
15766
|
Fri Jan 15 15:06:42 2021 |
Jon | Update | CDS | Expansion chassis from LHO | Koji asked me assemble a detailed breakdown
of the parts received from LHO, which I do
based on the high-res photos |
|
|
15767
|
Fri Jan 15 16:54:57 2021 |
gautam | Update | CDS | Expansion chassis from LHO | Can you please provide a link to this "list
of boards"? The only document I can
find is T1800302. |
|
|
15768
|
Fri Jan 15 17:04:45 2021 |
gautam | Update | LSC | Messed up LSC sensing | I want to lock the PRFPMI again (to commission
AS WFS). Have had some
success - but in doing characterization, |
|
|
15769
|
Sat Jan 16 18:59:44 2021 |
gautam | Update | LSC | Modulation depth measurement | I decided to analyze the data I took in
December more carefully to see if there are
any clues about the weird LSC sensing. |
|
|
15770
|
Tue Jan 19 13:19:24 2021 |
Jon | Update | CDS | Expansion chassis from LHO | Indeed T1800302 is
the document I was alluding to, but I completely
missed the statement about >3 GHz speed. |
|
|
15773
|
Wed Jan 20 10:13:06 2021 |
gautam | Update | Electronics | HV Power supply bypassing | Summary:
Installing 10uF bypass capacitors
on the High |
|
|
15775
|
Wed Jan 20 19:12:16 2021 |
gautam | Update | CDS | SLwebview fixed | After fixing multiple issues, the model
webviews are updating, should be done
by tomorrow. It should be obvious from the |
|
|
15777
|
Tue Jan 26 10:58:30 2021 |
gautam | Update | SUS | MC2 tickler stuck on | For whatever reason, the autolocker didn't
turn the tickle off for several
hours. Seems to work okay now. The linked |
|
|
15783
|
Thu Jan 28 22:34:21 2021 |
gautam | Update | SUS | De-whitening | Summary:
We will need de-whitening
filters for the BHD relay optics in order |
|
|
15786
|
Mon Feb 1 12:30:21 2021 |
gautam | Update | Electronics | More careful characterization | Summary:
Swapping out the KEPCO
HV supplies (linear) I was using for a pair |
|
|
15788
|
Tue Feb 2 17:09:17 2021 |
yehonathan | Update | BHD | SOS assembly | I set up a working area on the table next
to the south flow bench (see attachment).
I also brought in a rolling table for some |
|
|
15790
|
Tue Feb 2 18:24:54 2021 |
Koji | Update | BHD | SOS assembly | You can remove the components of the optical
table enclosure (black ones) and use the
optical table as your working area too. |
|
|
15791
|
Tue Feb 2 23:29:35 2021 |
Koji | Update | CDS | CDS crash and CDS/IFO recovery | I worked around the racks and the feedthru
flanges this afternoon and evening. This
inevitably crashed c1lsc real-time process. |
|
|
15792
|
Wed Feb 3 15:24:52 2021 |
gautam | Update | CDS | CDS crash and CDS/IFO recovery | Didn't get a chance to comment during the
meeting - This was almost certainly
a coincidence. I have never had to do |
|
|
15794
|
Wed Feb 3 18:53:31 2021 |
Koji | Update | CDS | CDS crash and CDS/IFO recovery | Really!? I didn't reboot the machines
between "sudo date" and "rtcds
start c1x0*". I tried rtcds. If it didn't |
|
|
15795
|
Wed Feb 3 21:28:02 2021 |
gautam | Update | CDS | CDS crash and CDS/IFO recovery | I am just reporting my experience - this
may be a new failure mode but I don't
think so. In the new RTCDS, the ntp server |
|
|
15796
|
Thu Feb 4 15:14:55 2021 |
Yehonathan | Update | BHD | SOS assembly | I gathered all the components I could find
from the SOS towers and the cleanroom and
put it all on the table next to the flow |
|
|
15798
|
Wed Feb 10 14:14:58 2021 |
gautam | Update | Electronics | Custom cables received | We received the custom cables to test the
new suspension electronics. They are under
my desk. So we are ready. |
|
|
15802
|
Wed Feb 10 21:14:03 2021 |
gautam | Update | Electronics | Production version of the HV coil driver tested | Summary:
I did what I consider to be a comprehensive
set of tests on the production version of |
|
|
15805
|
Thu Feb 11 18:21:39 2021 |
gautam | Update | SUS | MC suspension glitches | MC1
suspension is glitching again, so
this is a good chance to install the new |
|
|
15806
|
Fri Feb 12 15:03:48 2021 |
Jordan | Update | SUS | CoM on 3"->2" Adapter Ring for SOS | As it currently stands the Center of Mass
of the Adapter Ring/Optic assembly is 0.0175"
out of the plane formed by the suspension |
|
|
15808
|
Tue Feb 16 13:13:39 2021 |
Yehonathan | Update | BHD | SOS assembly | Gautam pointed out that there are extra
Sm-Co magnets stored in the clean optics
cabinet. |
|
|
15809
|
Tue Feb 16 14:56:44 2021 |
gautam | Update | SUS | aLIGO Sat Amp installed, powered | [jordan,
gautam]
Ran 60ft long cables from |
|
|
15810
|
Tue Feb 16 15:29:01 2021 |
Koji | Update | BHD | SOS assembly | The curie temp of SmCo seems about x2 (in
K) of the one for NdFeB. i.e. 600K vs 1000K.
So I believe 177degC = 450K is not an issue. |
|
|
15811
|
Tue Feb 16 22:59:36 2021 |
Yehonathan | Update | BHD | SOS assembly | Done.
Also, the magnets are nickel-plated.
I guess that doesn't matter for the baking |
|
|
15812
|
Wed Feb 17 13:59:35 2021 |
gautam | Update | DetChar | Summary pages | The summary pages had failed because of
a conda env change. We are dependent on detchar's |
|
|
15813
|
Wed Feb 17 13:59:43 2021 |
Koji | Update | SUS | CoM on 3"->2" Adapter Ring for SOS | Note from today's meeting:
1. Can we adjust the thickness of |
|
|
15814
|
Wed Feb 17 16:11:53 2021 |
gautam | Update | SUS | aLIGO Sat Amp installed, powered | There is some non-trivial sign flipping
in the sensors/coils in this new setup because
it is a hybrid one with the old interfacing |
|
|
15816
|
Thu Feb 18 15:15:12 2021 |
yehonathan | Update | SUS | OSEM testing for SOSs | I am setting up a testing rig for the OSEMs
we recently obtained. I found the schematic
for the OSEM assembly from which the pin |
|