| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
2518
|
Thu Jan 23 19:23:03 2020 |
anchal | DailyProgress | FSS | NFSS Boost Stage | Today Koji came to the lab to help me out
with the FSS and give me few tips.
We made some changes to the boost |
|
|
2519
|
Mon Jan 27 18:29:19 2020 |
anchal | DailyProgress | FSS | FSS Diagnostics - RFPD RF Out Spectrum | After the Notch improvement, I took 20
dB coupled outputs of the RF out ports of
the FSS RFPDs, SN009 (North) and SN010 (South), |
|
|
2520
|
Tue Jan 28 13:27:25 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | Added all documents to the LIGO document
for the FSS Plant Circuit LIGO-D2000020-v1.
The updated board and schematic are also |
|
|
2521
|
Wed Jan 29 14:49:48 2020 |
anchal | DailyProgress | BEAT | Beanote Spectrum vs FSS Gain Values | In a discussion with Craig sometime back,
it was brought up what happens when I lower
the gains of the FSS loops. So today I did |
|
|
2522
|
Wed Jan 29 15:58:26 2020 |
anchal | DailyProgress | BEAT | Beanote Spectrum vs FSS Gain Values |
Quote:
|
|
|
2523
|
Thu Jan 30 10:55:22 2020 |
anchal | Notes | BEAT | Lowest ever beatnote spectrum today. | Today we have measured the lowest beatnote
spectrum till now. This happened because
I set the FSS gain values to lower than the |
|
|
2524
|
Fri Feb 7 09:57:32 2020 |
anchal | DailyProgress | BEAT | Spanned gain parameter space in NFSS and checked beatnote | Yesterday I took beatnote measurements
and spanned gain values (COM and FAST) to
see the variation in beatnote with them. |
|
|
2525
|
Fri Feb 7 18:12:03 2020 |
anchal | DailyProgress | BEAT | Spanned gain parameter space in SFSS and checked beatnote | I took beatnote measurements and spanned
gain values (COM and FAST) on South side
to see the variation in beatnote with them. |
|
|
2526
|
Mon Feb 10 11:07:33 2020 |
anchal | DailyProgress | BEAT | Spanned gain parameter space in PMCs and checked beatnote | I took beatnote measurements and spanned
gain values in the PMC to see if stability
issues in PMC loops can be affecting the |
|
|
2527
|
Mon Feb 10 12:46:17 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | Board Plant Circuit should come in on Feb.
18th. It is really taking its time. |
|
|
2528
|
Mon Feb 10 17:41:25 2020 |
anchal | DailyProgress | scatter | Cleaned up table; Installed hex beam dumps | Today I cleaned up the table, removed Scott's
RFAM measurement setup and installed hex
beam dumps on the input rejection of faraday |
|
|
2529
|
Tue Feb 11 18:21:17 2020 |
anchal | DailyProgress | PMC | Can't keep my mind of this; Why PMC Error signal has these oscillations? | The PMC error signals have some weird broadened
oscillations in them:
|
|
|
2530
|
Wed Feb 12 10:01:04 2020 |
anchal | Notes | BEAT | Increased sampling rate to 125kSa/s; lowest noise in higher frequencies | I have increased the sampling rate of moku
to 125 kSa/s (fastest allowed) for the frequency-time
series acquisition. After reading matermost |
|
|
2531
|
Thu Feb 13 15:27:18 2020 |
anchal | DailyProgress | BEAT | Further iterated back and forth to optimized FSS Gains. | I took beatnote measurements and spanned
gain values in the PMC to see if stability
issues in PMC loops can be affecting the |
|
|
2532
|
Thu Feb 13 16:35:32 2020 |
anchal | DailyProgress | BEAT | BN Detector was saturated. Reduced laser powers. | I found that the beatnote detector was
actually saturating and the output was not
a good pure sinewave. I've reduced the |
|
|
2533
|
Thu Feb 13 18:00:30 2020 |
anchal | DailyProgress | scatter | blocked NF1811 with hex beam dump | I have blocked the unused output port of
the beam splitter before our beatnote detector
with a hex beam dump at (13, |
|
|
2534
|
Thu Feb 13 18:06:00 2020 |
anchal | DailyProgress | NoiseBudget | Adding dark noise measurement of beatnote detector SN101 | I measured dark noise of the beatnote detector
reaching moku and its effect on measured
beatnote frequency noise. |
|
|
2535
|
Fri Feb 14 10:59:13 2020 |
anchal | DailyProgress | BEAT | Beatnote noise lowered in low frequency region | With some of the changes done recently,
the beatnote noise has lowered in the low-frequency
region indicating reduction in scatter. |
|
|
2537
|
Fri Feb 14 16:46:47 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | The PCB came in and I have assembled it.
The preliminary look at the transfer function
on the AG4395A shows that there is a |
|
|
2538
|
Fri Feb 14 17:40:27 2020 |
anchal | DailyProgress | ISS | Installed ISS on both paths using SR560s | I've installed ISS on both paths using
3 SR560s each. Preliminary feedback is setup
to get a stable loop. More optimization with |
|
|
2539
|
Sat Feb 15 18:57:43 2020 |
rana | DailyProgress | ISS | Installed ISS on both paths using SR560s | you don't need 6(!!) SR560s - just
1 for each loop:
AC coupled,
1st |
|
|
2540
|
Mon Feb 17 16:08:23 2020 |
anchal | DailyProgress | BEAT | Beatnote noise lowered in low frequency region with ISS | After installing the preliminary ISS, which
I'll change tomorrow as per Rana's
suggestions, we see some reduction in the |
|
|
2541
|
Tue Feb 18 15:42:46 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | After switching out a bad opamp we have
clearer results.
Next steps: moving the real value |
|
|
2542
|
Thu Feb 20 17:42:23 2020 |
rana | DailyProgress | ISS | Installed New ISS on both paths using SR560s | I've installed new ISS consisting of
one SR560 per path.
ISS SR560 Details:
|
|
|
2543
|
Fri Feb 21 16:22:04 2020 |
anchal | DailyProgress | BEAT | Beatnote noise lowered in low frequency region with ISS | After installing the new ISS, the noise
is even lower in lower frequencies. Still
no change in the noisy peaks at 400 Hz and |
|
|
2544
|
Sun Feb 23 18:19:32 2020 |
rana | DailyProgress | ISS | Installed New ISS on both paths using SR560s |
too much gain peakin!
|
|
|
2545
|
Fri Feb 28 14:00:11 2020 |
anchal | DailyProgress | ISS | Installed New ISS on both paths using SR560s - PROBLEM | I'm currently struggling with a problem
in North ISS which I think needs to be documented
here. Here's the synopsis: |
|
|
2546
|
Sun Mar 1 16:34:31 2020 |
rana | DailyProgress | ISS | Installed New ISS on both paths using SR560s - PROBLEM | do
some step response and swept sine and post |
|
|
2547
|
Mon Mar 2 16:48:12 2020 |
anchal | DailyProgress | ISS | Follow-up, porbalem stopped happening, OLTF plot. | The issue isn't visible right now.
I'm not sure what changed but with a
similar power level, I'm able to increase |
|
|
2548
|
Tue Mar 3 10:02:12 2020 |
anchal | DailyProgress | BEAT | Lowest ever beatnote spectrum today! | Measurement at 3 am in the morning today
has been the lowest ever recorded beatnote
noise. The lasers have been locked for more |
|
|
2549
|
Tue Mar 3 11:49:16 2020 |
anchal | DailyProgress | ISS | Transmitted Laser Relative Intensity Noise | Attached are the latest transmitted RIN
measurements.
Measurement:
These |
|
|
2550
|
Tue Mar 3 17:13:04 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | Anchal and I connected the circuit to the
EOM and PZT in a closed loop (LIGO-D040105).
We looked at the output as seen in the Oscilloscope |
|
|
2551
|
Sat Mar 7 09:50:31 2020 |
anchal | DailyProgress | ISS | Transmitted Laser Relative Intensity Noise - Out of loop | Attached are the latest transmitted RIN
measurements.
Measurement:
I |
|
|
2552
|
Wed Mar 11 12:45:15 2020 |
rana | DailyProgress | ISS | Transmitted Laser Relative Intensity Noise - Out of loop | weird - why is the Gain different for in
loop and out of loop ? |
|
|
2553
|
Wed Mar 11 13:16:09 2020 |
anchal | DailyProgress | ISS | Transmitted Laser Relative Intensity Noise - Out of loop | These measurements take a long time as
I take a median over 500 single measurement
instances. I was able to increase gain later |
|
|
2554
|
Wed Mar 11 15:40:50 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | I added a capacitor to c8 in the FSS plant
D2000020. This yielded the transfer function
shown below. This seems to have pushed the |
|
|
2555
|
Wed Mar 11 16:43:55 2020 |
anchal | DailyProgress | ISS | Comparison between Out of loop vs In loop RIN | I took spectrum of Out-of-loop (OOL) photodiode
and In-loop (IL) photodiodes with transmitted
light from the cavities when ISS is on in |
|
|
2556
|
Thu Mar 12 11:06:35 2020 |
anchal | DailyProgress | BEAT | Lowest ever beatnote spectrum today! | Last night I switched off all the fans
in the lab and we have reached the lowest
ever recorded beatnote noise. |
|
|
2557
|
Thu Mar 12 16:21:49 2020 |
Ian MacMillan | Notes | FSS | FSS Plant Model v2 | We added hooked up the plant and measured
the in loop transfer function (shown below).
The circuit locked in the system... |
|
|
2558
|
Thu Mar 12 17:18:51 2020 |
rana | Notes | FSS | FSS Plant Model v2 | I think you have to protect this SimPlant
board from the HV from the FSS board ?
|
|
|
2559
|
Thu Mar 12 19:11:00 2020 |
shruti | DailyProgress | ISS | Removed half-wave plate in north path | [Anchal, Shruti]
We realized that the half-wave
plates before the EOAMs probably had no real |
|
|
2560
|
Mon Mar 16 16:16:17 2020 |
anchal | DailyProgress | ISS | Added true OOL transmission PD for South Path | Today, I added a new out-of-loop transmission
PD (Thorlabs PDA10CS) for the south path.
This will be helpful in future measurements |
|
|
2561
|
Tue Mar 17 18:03:22 2020 |
anchal | DailyProgress | ISS | Added true OOL transmission PD for North Path | Today, I added a new out-of-loop transmission
PD (Thorlabs PDA10CS) for the north path.
This will be helpful in future measurements |
|
|
2562
|
Wed Mar 18 12:51:22 2020 |
anchal | DailyProgress | BEAT | Super beatnote measurement analysis results | On March 13th around 7:30 pm, I started
a super measurement of the beatnote spectrum
for over 2 days. The script superBNSpec.py |
|
|
2563
|
Thu Mar 19 15:34:41 2020 |
anchal | DailyProgress | North Cavity | North path's buggy nature solved | I found out that since the slow PID of
the FSS used Cavity reflection DC level,
it is important that this path remains rigid |
|
|
2564
|
Sun Mar 22 17:23:29 2020 |
anchal | DailyProgress | North Cavity | North path's buggy nature NOT solved | It seems like this was never properly solved.
On Friday, the same problem was back again.
After trying relocking PMC and FSS on the |
|
|
2565
|
Wed Mar 25 15:50:57 2020 |
anchal | DailyProgress | North Cavity | North path's buggy nature NOT solved | Today, magically almost, the North Path
was found to be locking nicely without the
noise. I was waiting for the beatnote to |
|
|
2566
|
Mon Apr 13 16:52:30 2020 |
anchal | DailyProgress | BEAT | Beatnote measurements back on track | Since this morning atleast, I'm not
seeing the North Path unstability (see CTN:2565) |
|
|
2567
|
Tue Apr 14 12:24:16 2020 |
anchal | DailyProgress | North Cavity | North path's buggy nature Strikes Again! | Today at sharp 8:30 am, perfectly fine
running experiment went bad again. The North
path became buggy again with strong low frequency |
|
|
2568
|
Thu Apr 16 18:08:56 2020 |
anchal | DailyProgress | North Cavity | North path stopped being buggy | On wednesday around noon, the North Path
got back to stability. I captured this process
by going back to the FB data. The process |
|