| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
2265
|
Mon Dec 17 22:13:03 2018 |
anchal | DailyProgress | TempCtrl | Proposed circuit for cavity temperature sensor Part 2 | The second stage of the amplifier for temperature
sensor would be subtractor circuits using
OP27G. |
|
|
2266
|
Wed Dec 19 11:01:00 2018 |
awade | DailyProgress | TempCtrl | Proposed circuit for cavity temperature sensor Part 2 | Missing current excitation to RTD?
I
don't know if I'm missing it, or
if you've yet to add it, but can't |
|
|
2267
|
Wed Dec 19 14:00:55 2018 |
anchal | DailyProgress | TempCtrl | Proposed circuit for cavity temperature sensor Part 2 | About the current source:
The
current excitation circuit is there, it is
just in another page in the schematic. I'm |
|
|
2268
|
Wed Dec 19 17:47:02 2018 |
anchal | DailyProgress | TempCtrl | Cavity Temperature Sensor Circuit v1.1 | From the review of PSL:2266 and
the promises I made in PSL:2267,
I think I have fixed the circuit. Corrected |
|
|
2269
|
Mon Dec 24 16:52:26 2018 |
rana | DailyProgress | TempCtrl | Cavity Temperature Sensor Circuit v1.1 | post a plot of the times series and noise
spectrum
Here is a link on how to choose |
|
|
2270
|
Tue Dec 25 11:45:15 2018 |
anchal | DailyProgress | TempCtrl | Vacuum Can Temperature Sensors (AD590) transimpedance amplifier board test | Yesterday, I put two boards of LIGO-D1800304
with two pairs of circuits populated in each
of them for testing. |
7x |
|
2271
|
Wed Dec 26 14:09:29 2018 |
anchal | Notes | EPICS | ws1 unable to read/write on some EPICS channels | ws1 is unable to read and write on some
EPICS channels while I can see these channels
in fb4 or acromag1. These channels are: |
|
|
2272
|
Fri Jan 4 16:42:28 2019 |
anchal | Summary | NoiseBudget | Latest noisebudget update. |
Since we are working on temperature
control of cavities, we worked out a hack
to still take beat note spectrum meanwhile.
|
|
|
2273
|
Fri Jan 4 19:04:29 2019 |
awade | DailyProgress | RFAM | Time to look at RF AM and RIN | That roll up in the HF range to 3 kHz hump
looks suspect.
PLL?
We need to check |
|
|
2274
|
Fri Jan 4 19:17:00 2019 |
anchal | Summary | TempCtrl | Vacuum Can Temperature Sensors (AD590) transimpedance amplifier board test - RESULTS | Over the break, the test of Vacuum Can
Temperature Sensors transimpedance circuit
was running and fb4 has logged the values. |
|
|
2275
|
Wed Jan 9 17:25:38 2019 |
anchal | DailyProgress | RFAM | Time to look at RF AM and RIN | I measured RIN of the two paths yesterday
through taking spectrum of transmission PDs
and measured cross-correlation with the Beatnote. |
|
|
2276
|
Wed Jan 9 19:05:56 2019 |
anchal | DailyProgress | RFAM | Time to look at RF AM and RIN | Preliminary testing
I hooked
up an HP8560E to RF port of the South FSS
Refl RFPD. I unlocked laser from the cavity |
|
|
2277
|
Thu Jan 10 10:39:27 2019 |
anchal | DailyProgress | NoiseBudget | New noise budget code is ready, but | The new noise budget code is ready. However,
there are few discrepancies which still need
to be sorted. |
|
|
2278
|
Thu Jan 10 11:38:53 2019 |
awade | DailyProgress | RFAM | Time to look at RF AM and RIN | Is
this the resonant EOM or a BBEOM driven with
an external circuit? The driving requirements |
|
|
2279
|
Thu Jan 10 14:19:46 2019 |
anchal | DailyProgress | RFAM | Time to look at RF AM and RIN | I found this paper on OSA: Control
of residual amplitude modulation in Lithium
Niobate phase modulators. It suggests |
|
|
2280
|
Thu Jan 10 17:30:24 2019 |
anchal | DailyProgress | RFAM | Time to look at RF AM and RIN | We measured the modulation index of 0.142
rad when we installed the PMC (See PSL:2251).
I checked both PMC loops, none of them are |
|
|
2281
|
Thu Jan 10 18:52:20 2019 |
anchal | DailyProgress | RFAM | Time to look at RF AM and RIN | I think I found the culprit. the polarizer
behind the EOM (PMC loop EOM) was a multi-order
one and hence was extremely sensitive to |
|
|
2282
|
Sat Jan 12 13:11:02 2019 |
awade | DailyProgress | RFAM | Time to look at beatnote after RF AM and RIN tuneup | Nice.
It would be a good time to retake
the BN + cross spectrum with RIN to see if |
|
|
2283
|
Wed Jan 16 11:07:41 2019 |
anchal | DailyProgress | NoiseBudget | Beatnote after RF AM and RIN tuneup | Intensity noise to the beatnote transfer
function
I resurrected
the AEOM power control lines with SMA cables |
|
|
2284
|
Wed Jan 16 22:07:44 2019 |
awade, anchal | DailyProgress | PLL | PLL noise from the Marconi 2023A FG | [awade, anchal]
This is not a detailed post as
I didn't collect data. We need |
|
|
2285
|
Thu Jan 17 11:55:12 2019 |
anchal | Summary | TempCtrl | Vacuum Can Temperature Sensors (AD590) transimpedance amplifier board noise test | I wanted to take a direct spectrum noise
measurement of the circuit. However, if I
have simply hooked the output of the circuit |
|
|
2286
|
Fri Jan 18 13:10:02 2019 |
anchal | DailyProgress | PLL | PLL noise from the Marconi 2023A FG | I took the noise spectrum of beat note
in PLL when it is fed with a low noise Wenzel
Crystal Oscillator of frequency 24.483 MHz |
|
|
2287
|
Mon Jan 21 19:01:11 2019 |
anchal | Notes | PLL | PLL Transfer Function and Noise Study | I see that we were lacking in complete
documentation of PLL transfer function and
noise analysis. I made this document for |
|
|
2288
|
Tue Jan 22 19:04:51 2019 |
anchal | DailyProgress | PLL | New Focus 1811-FC Dark noise Measurement | We suspected if the wideband RF detector
New
Focus 1811-FC could be the source of |
|
|
2289
|
Tue Jan 22 20:26:18 2019 |
awade | DailyProgress | TempCtrl | Running relay controller overnight on refcavs | Beat note is still not under control. Its
drifting at 10 kHz/min, too much for a lower
range marconi measurement. |
|
|
2290
|
Wed Jan 23 11:28:53 2019 |
awade | DailyProgress | TempCtrl | Correcting BN after running relay controller overnight on refcavs | This test relay test was a failure.
I got impatient late last night and
downed the midpoint diff heating to 0.5732 |
|
|
2291
|
Wed Jan 23 11:43:02 2019 |
awade, anchal | DailyProgress | PLL | New Focus 1811-FC Dark noise Measurement | The first measurement here seems like a
smoking gun for limiting noise. A mixer
down converted noise of 1.3 µV/rtHz (directly |
|
|
2292
|
Wed Jan 23 18:13:48 2019 |
anchal and awade | DailyProgress | FSS | FSS Gain and Offset tuning | Today we checked FSS Common path and Fast
path transfer functions to see unity gain
frequencies and any possible optimizations. |
|
|
2293
|
Thu Jan 24 12:38:47 2019 |
anchal | DailyProgress | NoiseBudget | Beat Note Noise Spectrum after tuning FSS Loop | PLL Readout Noise and Open-Loop
Transfer Function:
I
remeasured dark noise of wideband photodetector |
|
|
2294
|
Thu Jan 24 14:24:10 2019 |
awade | DailyProgress | TempCtrl | Custom implementation of PIDLocker script for finer control of intergration on cav heaters | Probably a lot of our problems of the PID
tuning of the cavity temperature controls
(for controlling BN freq) come back back |
|
|
2295
|
Fri Jan 25 10:46:24 2019 |
awade | DailyProgress | TempCtrl | PID locking of cavity heaters to BN | Testing of this seems to confirm that lower
intergrator values are the way to go.
We had excellent locking with <1.2 kHz/min |
|
|
2296
|
Fri Jan 25 15:45:48 2019 |
anchal | DailyProgress | TempCtrl | PID locking of cavity heaters to BN | About BN slope detector: I
just made few extra EPICS channels to do
this. But acromag1 hasn't rebooted since |
|
|
2297
|
Mon Jan 28 10:56:49 2019 |
awade and anchal | DailyProgress | NoiseBudget | Noisebudget with Resonant Beat Note Photo Detector - Touching new lows | Shot Noise of Photocurrent:
Assuming
0.5 mW power is falling on the wideband beat
note photodetector New |
|
|
2298
|
Tue Jan 29 17:47:14 2019 |
anchal | DailyProgress | TempCtrl | Cavity Temperature Sensor Breadboard Circuit Noise Analysis | Here are the noise spectrum and time series
plots that were asked of me ages ago. Apologies
for the delay. I've also attached the |
|
|
2299
|
Wed Jan 30 12:17:05 2019 |
rana | DailyProgress | TempCtrl | Cavity Temperature Sensor Breadboard Circuit Noise Analysis | that's a good start, but we don't
care about the noise above 10 Hz. So
you should re-take the data and plot |
|
|
2300
|
Wed Jan 30 15:07:32 2019 |
awade, anchal | HowTo | FSS | Shot noise in FSS loops? | The FSS at some point is going to be limited
by shot noise. I understand that the apparent
frequency noise should go as [1]: |
|
|
2301
|
Fri Feb 1 14:59:01 2019 |
awade, anchal | HowTo | FSS | Noise tallies | We've hit a flat (white) noise floor
at around 70 mHz/rtHz. Time to tally
all the unaccounted for noises. |
|
|
2302
|
Fri Feb 1 20:20:11 2019 |
awade | HowTo | FSS | Modifying North FSS EOM path | I'm implementing the suggested cap
and resistor updates in the last post (PSL:2301). |
|
|
2303
|
Tue Feb 5 11:40:02 2019 |
awade | HowTo | FSS | Modifying South FSS boost | Shortening the capacitor leads on U7 boost
I
checked the boost stage on U7 of LIGO-D040105-C on
the south path box (37 MHz). It appears |
|
|
2304
|
Tue Feb 5 20:39:52 2019 |
anchal | Summary | FSS | Complete model of TTFSS box with TF and crossover analysis | I'm attaching the first results of
the transfer function from liso model
of complete TTFSS box. I've also attached |
|
|
2305
|
Wed Feb 6 19:13:06 2019 |
anchal | Summary | FSS | Complete model of TTFSS box with TF and crossover analysis | I added some more graphs to our FSS
analysis.
I modeled AD602 variable |
|
|
2306
|
Wed Feb 6 21:30:24 2019 |
awade | Summary | FSS | Complete model of TTFSS box with TF and crossover analysis | Hmm... Last estimate of V_rms applied to
EOM can't be true.
If laser frequency noise is |
|
|
2307
|
Thu Feb 7 10:33:27 2019 |
anchal | Summary | FSS | Complete model of TTFSS box with TF and crossover analysis |
Quote:
|
|
|
2308
|
Tue Feb 26 02:45:20 2019 |
anchal | Notes | Computers | Migrating epics channels from acromag1 to c3iocserver | We have been thinking for a while to migrate
all epics channels from acromag1 (10.0.1.33) to
c3iocserver (10.0.1.36) which is rack mount |
|
|
2309
|
Tue Mar 12 17:04:03 2019 |
anchal and awade | Summary | Computers | Migrating epics channels from acromag1 to c3iocserver |
The migration of all EPICS channel
hosting and all python programmes has been
done from Acromag1 to C3IOCServer. Now Acromag1 |
|
|
2310
|
Sun Mar 17 18:28:06 2019 |
awade and anchal | Summary | Computers | Migrating epics channels from acromag1 to c3iocserver: killing acromag1 services | Wandered into the PSL just now. Slow
controls were going wild. Traced it
back to the fact that acromag1 and its auto-restarting |
|
|
2311
|
Tue Mar 19 16:39:20 2019 |
anchal | DailyProgress | FSS | Need to track down 60 Hz spike source in FSS | The bad news...
We
were curious on actual actuation signal being
sent to EOM by the TTFSS boxes.
So |
|
|
2312
|
Sat Mar 23 21:50:40 2019 |
anchal | Summary | Electronics Equipment | Power tripping incident and follow-up | This week on 19th March in the evening,
I was working on replacing the GND connections
of the power supply with thicker wires and |
|
|
2313
|
Wed Apr 3 16:23:26 2019 |
anchal | DailyProgress | PMC | Rehabilitation of PMCs | Since the last incident of power
supply tripping, I tested all photodiodes
and electronics in the lab one by one. During |
|
|
2314
|
Thu Apr 4 15:33:34 2019 |
anchal | DailyProgress | PMC | Rehabilitation of PMCs | Today, I tried to replace the Reflection
Photodiode on South PMC with another 14.75
MHz Resonant (which from test port analysis |
|