| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
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 |
|
|
15817
|
Thu Feb 18 15:33:21 2021 |
gautam | Update | SUS | aLIGO Sat Amp installed, powered and commissioned | The WFS servo was recommissioned. The matrix
can be tuned a bit more, but for now, I've
recovered the old performance and the alignment |
|
|
15818
|
Thu Feb 18 18:05:04 2021 |
gautam | Update | SUS | aLIGO Sat Amp characterization | Before installation, I performed a bunch
of tests on the aLIGO sat amp. All the measurements
were made with the dummy suspension box substituting |
|
|
15819
|
Thu Feb 18 20:20:25 2021 |
Koji | Update | SUS | aLIGO Sat Amp characterization | Yeah, it's really inconsistent. You
had 35mA LED drive and the current noise
of the noisy channel was 5e-7 A/rtHz at 1Hz. |
|
|
15821
|
Fri Feb 19 12:21:04 2021 |
Yehonathan | Update | BHD | SOS assembly | A summary of things that need to be fabricated/purchased/done:
|
|
|
15822
|
Fri Feb 19 13:38:26 2021 |
gautam | Update | LSC | PRFPMI | I forgot that I had already done some investigation
into recovering the PRFPMI lock after my
work on the RF source. I don't really |
|
|
15823
|
Fri Feb 19 15:17:51 2021 |
Jordan | Update | SUS | CoM Range on 3"->2" Adapter Ring for SOS | Adjusting the thickness of the cylindrical
hole for the mirror on the 2" optic
sleeve, from .6875" to .61" thick, |
|
|
15824
|
Fri Feb 19 16:06:01 2021 |
Koji | Update | SUS | CoM Range on 3"->2" Adapter Ring for SOS | We want to move the CoM with the adjustment
range so that the residual deviation is adjusted
by the bottom dumbbell. 0.0003" is well |
|
|
15825
|
Fri Feb 19 16:14:16 2021 |
gautam | Update | SUS | CoM Range on 3"->2" Adapter Ring for SOS | I briefly talked with Jordan about this.
This suspension will have OSEMs right? With
400ohm series resistance for the coil drivers, |
|
|
15826
|
Fri Feb 19 16:55:26 2021 |
Koji | Update | SUS | CoM Range on 3"->2" Adapter Ring for SOS | Jordan's screenshot actually shows
that the vertical distance (Y) is 0.0000".
We want to have the vertical distance of |
|
|
15827
|
Fri Feb 19 18:22:42 2021 |
rana | Update | LSC | PRFPMI sensiing matrix woes | I would:
look at the free swingin
michelson. Should be able tu null that siggnal |
|
|
15829
|
Sat Feb 20 16:20:33 2021 |
gautam | Update | General | Housekeeping + PRMI char | In prep to try some of these
debugging steps, I did the following.
ndscope updated from 0.7.9 to |
|
|
15831
|
Sun Feb 21 20:51:21 2021 |
rana | Update | General | Housekeeping + PRMI char | I'm curious to see if the demod phase
for MICH in REFL & AS chamges between
thi simple Mcihelson and PRMI. IF there's |
|
|
15832
|
Mon Feb 22 14:06:49 2021 |
Yehonathan | Update | SUS | OSEM testing for SOSs | Continuing with the OSEM testing. I measure
the resistance of the wires from the RLC
meter to the coil to be ~ 0.9ohm. I will |
|
|
15833
|
Mon Feb 22 14:53:47 2021 |
gautam | Update | CDS | dtt-ezca-tools installed on rossa | The defaults cds-crtools didn't come
with some of the older ezcautils (like ezcaread,
ezcawrite etc). This is now packaged for |
|
|
15834
|
Tue Feb 23 00:10:05 2021 |
gautam | Update | General | Demod char part 1 | I measured the conversion efficiencies
for all the RFPD demod boards except the
POP port ones. An RF source was used to drive |
|
|
15835
|
Tue Feb 23 20:55:19 2021 |
Koji | Update | SUS | OSEM testing for SOSs | I can't obtain a consistent view between
the existing drawings/photographs and your
pin assignment. Please review the pin assignment |
|
|
15837
|
Wed Feb 24 10:09:16 2021 |
yehonathan | Update | SUS | OSEM testing for SOSs | Yes, my phone camera mirrored the image.
Sorry for the confusion.
I see you already uploaded the |
|
|
15838
|
Wed Feb 24 10:23:03 2021 |
Yehonathan | Update | SUS | OSEM testing for SOSs | Continuing with the new rig, I measure
the resistance of the cable leading to the
coil to be 0.08+(0.52-0.08)+(0.48-0.08)=0.9ohm. |
|
|
15839
|
Wed Feb 24 11:53:24 2021 |
gautam | Update | General | Demod char part 2 | I measured the noise of the I/F outputs
of all the LSC demodulators. I made the measurement
in two conditions, one with the RF input |
|
|
15840
|
Wed Feb 24 12:11:08 2021 |
gautam | Update | General | Demod char part 3 | I did the characterization discussed at
the meeting today.
RF signal at 100 Hz offset |
|
|
15841
|
Wed Feb 24 12:29:18 2021 |
gautam | Update | General | Input pointing recovered | While working at the LSC rack, I lost the
input pointing into the IFO (the TT wiring
situation is apparently very fragile, and |
|
|
15842
|
Wed Feb 24 22:13:47 2021 |
Jon | Update | CDS | Planning document for front-end testing | I've started writing up a rough testing
sequence for getting the three new front-ends
operational (c1bhd, c1sus2, c1ioo). Since |
|
|
15843
|
Thu Feb 25 14:30:05 2021 |
gautam | Update | CDS | new c1bhd setup - diskless boot | I've set up one 2U server unit received
from KT in the control room area (the fans
in it are pretty loud but other than |
|
|
15844
|
Thu Feb 25 16:50:53 2021 |
gautam | Update | General | PRMI sensing matrix | After all the work at the LSC rack over
the last couple of days, I re-locked the
PRMI (ETMs misaligned), and measured the |
|
|
15845
|
Thu Feb 25 20:37:49 2021 |
gautam | Update | General | Setting modulation frequency and checking IMC offset | The Marconi frequency was tuned by looking
at
The ~3.68 MHz (= 3*f1 - |
|
|
15846
|
Fri Feb 26 16:31:02 2021 |
gautam | Update | Electronics | Production version of the HV coil driver tested with KEPCO HV supplies | Koji asked me to test the production version
of the coil driver with the KEPCO HV supplies.
See |
|
|
15847
|
Fri Feb 26 20:20:43 2021 |
Koji | Update | Electronics | Production version of the HV coil driver tested with KEPCO HV supplies | This is very disappointing. Even with KEPCO
linear supply with the improved HV driver
circuit, the noise level is significantly |
|
|
15848
|
Sat Feb 27 17:25:42 2021 |
gautam | Update | Electronics | Production version of the HV coil driver tested with KEPCO HV supplies | I will try the test of switching out KEPCOs
one at a time for the HP. Given that the
passive RC filter doesn't filter |
|
|
15849
|
Sun Feb 28 16:59:39 2021 |
rana, gautam | Update | LSC | more PRMI checks here: what it is ain't exactly clear | On Friday evening we checked out
a few more things, somewhat overlapping with
previous tests. All tests done with PRMI |
|
|
15850
|
Sun Feb 28 22:53:22 2021 |
gautam | Update | LSC | more PRMI checks here: what it is ain't exactly clear | I looked into this a bit more and crossed
off some of the points Rana listed. In order
to use REFL 55 as a sensor, I had to fix |
|
|
15853
|
Mon Mar 1 16:27:17 2021 |
gautam | Update | LSC | PRM violin filter excessive? | The PRM violin filter seems very suboptimal
- the gain peaking shows up in the MICH OLTF,
presumably due to the MICH-->PRM LSC output |
|
|
15854
|
Tue Mar 2 13:39:31 2021 |
rana | Update | LSC | PRM violin filter excessive? | agreed, seems excessive. I always prefer
bandstop over notch in case the eigenfrequency
wanders, but the bandstop could be made to |
|
|
15855
|
Tue Mar 2 19:52:46 2021 |
gautam | Update | LSC | REFL55 demod board rework | There were multiple problems with the REFL55
demod board. I fixed them and re-installed
the board. The TFs and noise measured on |
|
|
15856
|
Wed Mar 3 11:51:07 2021 |
Yehonathan | Update | SUS | OSEM testing for SOSs | I finished testing the OSEMs. I put all
the OSEMs back in the box. The OSEMS were
divided into several bags. I put the OSEM |
|
|
15859
|
Wed Mar 3 22:13:05 2021 |
gautam | Update | LSC | REFL55 demod board rework | After this work, I measured that the orthogonality
was poor. I confirmed on the bench that the
PQW-2-90 |
|
|
15860
|
Wed Mar 3 23:23:58 2021 |
gautam | Update | ALS | Arm cavity scan | I see no evidence of anything radically
different from my PSL table optical
characterization in the IMC transmitted |
|
|
15864
|
Thu Mar 4 23:16:08 2021 |
Koji | Update | LSC | REFL55 demod board rework | A new hybrid splitter (DQS-10-100) was
installed. As the amplification of the final
stage is sufficient for the input level of |
|
|
15867
|
Fri Mar 5 13:53:57 2021 |
gautam | Update | LSC | REFL55 demod board rework | 0 dBm ~ 0.63 Vpp. I guess there is ~4dB
total loss (3dB from splitter
and 1dB from total excess loss above theoretical |
|