| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
15782
|
Thu Jan 28 21:44:45 2021 |
gautam | Summary | BHD | HAM-A Coil Driver measurements After modifications | Looks fine to me visually but the verdict
can only be made once the z:p locations are quantitatively confirmed,
and the noise tests pass. It would be interesting |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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. |
|
|
15800
|
Wed Feb 10 15:25:45 2021 |
gautam | Summary | BHD | Satellite Amplifier Output Offset measurements | Why not just do this test with the dummy
suspension box and CDS system? I think Rich's
claim was that the intrinsic LED RIN was |
|
|
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 |
|
|
15809
|
Tue Feb 16 14:56:44 2021 |
gautam | Update | SUS | aLIGO Sat Amp installed, powered | [jordan,
gautam]
Ran 60ft long cables from |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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, |
|
|
15828
|
Sat Feb 20 10:01:48 2021 |
gautam | Summary | Electronics | A bunch of electronics received | Will we also be receiving the additional
34 Satellite Amplifier PCBs? |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
15852
|
Mon Mar 1 12:36:38 2021 |
gautam | Summary | IMC | getting familiar with IMC controls | Pretty minor thing - but PMCT and PMCR
were switched on Quad 2 for whatever reason.
I switched them back because I prefer the |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
15868
|
Fri Mar 5 15:03:28 2021 |
gautam | Summary | Electronics | A bunch of electronics received | The PCBs for the D1002593
BIO I/F (5pcs ea of D1001050
and D1001266) |
|
|
15871
|
Fri Mar 5 16:24:24 2021 |
gautam | Update | LSC | REFL55 demod board re-installed in 1Y2 | I don't have a good explanation why,
but I too measured similar numbers to what
Koji measured. The overall conversion gain |
|
|
15873
|
Fri Mar 5 22:25:13 2021 |
gautam | Update | LSC | PRMI 1f SB locking recovered | Now that the REFL55 signal chain is capable
of providing balanced, orthogonal readout
of the two quadratures, I was able to recover |
|
|
15874
|
Sat Mar 6 12:34:18 2021 |
gautam | Update | LSC | Sensing matrix settings messed with | To my dismay, I found today that somebody
had changed the oscillator frequencies for
the sensing matrix infrastructure we have. |
|
|
15875
|
Sun Mar 7 15:26:10 2021 |
gautam | Update | LSC | Housekeeping + more PRMI |
Beam pointing into PMC was tweaked
to improve transmission.
AS110
photodiode was re-installed on the AS table |
|
|
15878
|
Mon Mar 8 12:40:35 2021 |
gautam | Summary | training | Investigate how-to XARM locking | For the arm locking, the "Restore
Xarm (XARM POX)" script from the "IFO_CONFIGURE"
MEDM screen should get you there (I just checked |
|
|
15879
|
Mon Mar 8 12:54:54 2021 |
gautam | Update | Equipment loan | 40m-->Cryo |
Busby box
SR554 transformer
preamplifier
|
|
|
15880
|
Mon Mar 8 17:09:29 2021 |
gautam | Update | SUS | PRM coil actuators heavily imbalanced | I realized I hadn't checked the PRM
actuator as thoroughly as I had the others.
I used the Oplev as a sensor to check the |
|
|
15883
|
Mon Mar 8 22:01:26 2021 |
gautam | Update | LSC | More PRMI | There are still many mysteries remaining
- e.g. the MICH-->PRCL contribution still
can't be nulled. But for now, I have |
|
|
15887
|
Tue Mar 9 14:37:26 2021 |
gautam | Summary | SUS | PRM suspension | The PRM got tripped ~5AM this morning.
The cause is unclear - the seismometer reports
elevated activity ~10 minutes before the |
|
|
15892
|
Wed Mar 10 00:32:03 2021 |
gautam | Update | LSC | PRFPMi | The interferometer can nearly be locked
again. I was unable to fully hand off control
from ALS-->RF, I suspect I may be using |
|
|
15894
|
Wed Mar 10 11:55:22 2021 |
gautam | Update | SUS | PRM suspension suspect | The procedure is that the optic is kicked
to excite it, and allowed to ring down for
~1ksec, with damping turned off. The procedure |
|
|
15895
|
Wed Mar 10 15:00:16 2021 |
gautam | Summary | IMC | IMC free swinging prep | Did you fix this issue? It is helpful to
post a screenshot of the offending MEDM screen
in addition to witticisms. The elog says |
|
|
15898
|
Wed Mar 10 17:35:47 2021 |
gautam | Update | SUS | Spooky action at a distance | As I am sitting in the control room, the
PRM suspension watchdog tripped again. This
time, there is clearly no |
|
|
15899
|
Wed Mar 10 19:58:27 2021 |
gautam | Update | LSC | SR785 hooked up to CM board | In preparation for later today evening.
The TT alignment wasn't visibly disturbed. |
|