 Fri May 21 12:12:11 2021, Paco, Update, NoiseBudget, AUX PDH loop identification
|
[Anchal, Paco]
We went into 40m to identify where XARM PDH loop control elements are. We didn't touch anything, but this is to note we went in there twice
at 10 AM and 11:10 AM. |
Fri May 21 00:15:33 2021, Koji, Update, Electronics, DC Power Strip delivered / stored 9x
|
DC Power Strip Assemblies delivered and stored behind the Y arm tube (Attachment 1)
7x 18V Power Strip (Attachment 2)
7x 24V Power Strip (Attachment 2)
7x 18V/24V
Sequencer / 14x Mounting Panel (Attachment 3)
DC Power Cables 3ft, 6ft, 10ft (Attachments 4/5)
DC |
|
Thu Aug 20 00:21:51 2020, gautam, Update, Electronics, First look at HV coil driver
|
Summary:
A single channel of this board was stuffed (and other channels partially populated). The basic tests passed, and nothing exploded! |
 Sun Aug 23 23:36:58 2020, gautam, Update, Electronics, First look at HV coil driver
|
Summary:
A more careful analysis has revealed some stability problems. I
see oscillations at frequencies ranging from ~600kHz to ~1.5 MHz, depending on the voltage output requested, of ~2 V pp at the high-voltage output |
|
Wed Aug 26 16:12:25 2020, gautam, Update, Electronics, Test mass coil current requirements
|
Attachment #1 is a summary of the
current to each coil on the suspensions. The situation is actually a little worse than I remembered - several coils are currently drawing in excess of
10mA. However, most of this is due to a YAW correction, which can be fixed somewhat more easily than a PIT correction. So I think the circuit with a gain |
|
Tue Sep 1 15:39:04 2020, gautam, Update, Electronics, HV coil driver oscillations fixed
|
Summary:
Increasing the compensation capacitance (470 pF now instead of 33 pF) seems to have fixed the oscillation
issues associated with this circuit. However, the measured noise is in excess of the |
|
Thu Oct 22 11:14:47 2020, gautam, Update, Electronics, HV coil driver packaged into 2U chassis
|
I packaged the HV coil driver into a 2U chassis, hoping for better shielding from pickup. There is still considerable
excess noise in measurement vs model around 100 Hz, see Attachment
#1. The projected displacement noise from this noise contribution is shown in |
|
Thu Oct 22 13:04:42 2020, rana, Update, Electronics, HV coil driver packaged into 2U chassis
|
| what is the noise level before the HV stage? i.e. how well is the acromag noise being filtered? |
|
Thu Oct 22 22:01:53 2020, gautam, Update, Electronics, HV coil driver packaged into 2U chassis
|
| It's not so easy to directly measure this I think, because the filtering is rather aggressive. Attachment #1 shows the measured transfer function (dots) vs the model and Attachment #2 shows the noise. I think this checks out - but I can't definitively |
|
Fri Oct 23 09:03:43 2020, anchal, Update, Electronics, HV coil driver packaged into 2U chassis
|
Andrew made a battery-powered 0.7 nVrtHz input-referred noise pre-amplifier for gain of 200. That might help you.
Quote:
we'd need a preamp with better than 1nV/rtHz to directly measure the noise I guess. |
|
Thu Nov 12 14:55:35 2020, gautam, Update, Electronics, More systematic noise characterization
|
Summary:
I now think the excess noise in this circuit could be coming from the KEPCO switching power supply (in fact, the supplies are linear,
and specd for a voltage ripple at the level of <0.002% of the output - this is pretty good I think, hard to find much better). |
|
Thu Nov 12 15:40:42 2020, Koji, Update, Electronics, More systematic noise characterization
|
Yes. The datasheet has a recommendation circuit with 10uF caps. Companies are careful to show reproducible, reliably functional circuit examples on datasheets.
So, if the caps are there you should try to replicate the design.
Quote:
|
|
Mon Nov 16 00:02:34 2020, rana, Update, Electronics, More systematic noise characterization
|
true. also try to choose a cap with a goow high frequency response. In the Electronics Noise book by Ott there's some graph about this. I bet you
good do a Bing search and also find something more modern. Basically we want to make sure that the self resonance is not happening at low frequencies.
Might be tought to find one with a good HF response, a high voltage rating, and > 1uF. |
|
Wed Jan 20 10:13:06 2021, gautam, Update, Electronics, HV Power supply bypassing
|
Summary:
Installing 10uF bypass capacitors on the High Voltage power supply
line for the HV coil driver circuit doesn't improve the noise. The excess bump around a few hundred Hz is still present. How |
|
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 of HP6209s
I borrowed from Rich has improved the noise performance somewhat.
However, there |
|
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 the high voltage coil driver circuit. I think the
performance is now satisfactory and the circuit is ready for the production build. Barring objections from anyone, I will ask Chub to place an order for |
|
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 Attachment #1 for the results. For comparison, I've added a single trace from the measurements made with
the HP supplies. I continue to see excess noise with the KEPCO supplies. Note that in the production version of the board that was tested, there are a |
|
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 higher than the 20kOhm
R thermal noise.
What is special with the HP supplies? Can you replace KEPCOs with the HP supply, one by one to specify which one is making the noise bad? |
|
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 out the excess, I
am wondering if the KEPCO is somehow polluting the circuit ground? The measurement was made between the circuit side of R24 (see schematic)
and a ground testpoint, so the passive R23/C15 pole should filter the noise above ~15 Hz. |
|
Thu May 20 16:56:21 2021, Koji, Update, Electronics, Production version of the HV coil driver tested with KEPCO HV supplies
|
HP HV power supply ( HP6209
) were returned to Downs |
|
Wed May 12 14:23:20 2021, Jordan, Update, SUS, Mass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units
|
| |
|
Wed May 12 16:53:59 2021, Koji, Update, SUS, Mass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units
|
No, this is the property of the suspension assembly. The mass says 10kg
Could you do the same for the testmass assembly (only the suspended part)? The units are good, but I expect that the values will be small. I
want to keep at least three significant digits. |
|
Wed May 12 17:06:52 2021, Jordan, Update, SUS, Mass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units
|
Here are the mass properties for the only the test mass assembly (optic, 3" ring, and wire block). (Updated with g*mm^2)
Quote:
No, this is the property of the suspension assembly. The mass says 10kg |
|
Wed May 19 18:29:41 2021, Koji, Update, SUS, Mass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units
|
Calculation for the SOS POS/PIT/YAW resonant frequencies
- Nominal height gap between the CoM and the wire clamping point is 0.9mm (cf T970135)
- To have the similar res freq for the optic with the 3" metal sleeve is 1.0~1.1mm. |
|
Wed Apr 21 19:28:03 2021, Anchal, Update, PSL, PSL/IFO recovery
|
[Anchal, Koji]
Removed the top sheet
Opened first from the door side so that any dust would spill outside.
Then
rolled the sheet inward to meet in the middle.
Repeated this twice for the 2 HEPA filters.
Removed the sheets on |
|
Wed Apr 21 19:43:20 2021, Koji, Update, PSL, New HEPA speed control
|
The new HEPA speed controllers are attached at the middle of the HEPA unit (not at the edge of the unit)... (Attachment 1)
You still need a step./stool to touch the knob and need a ladder for a more precise setting.
We still don't know the optimal speed of the nominal IFO operation. For now, the HEPAs are running at the max speed (Attachment 2). |
|
Thu Apr 22 14:41:55 2021, Chub, Update, PSL, New HEPA speed control
|
When adjusting the blower speed, give the blower at least 30 seconds to speed up or slow down to the set speed. The flywheel effect of the big
motor armature and blower mass requires time to follow the control current. Note the taller Flanders HEPA filters. These and the new intake
filters should keep the PSL air clean for a long time! |
|
Fri Apr 23 18:00:02 2021, gautam, Update, PSL, HEPA speed lowered
|
I will upload some plots later - but in summary, I set the HEPA speed to ~40%. I used (i)IMC transmission RIN, (ii) Arm cavity transmission RIN and (iii)
ALS beat noise as 3 diagnostics, to see how noise in various frequency bands for these signals change as a function of the HEPA speed. The MC2T RIN shows
elevated noise between 1-10Hz at even the lowest speed I tried, ~20% of the max on each blower. The elevated noise extended to ~50-70 Hz for HEPA speeds |
|
Fri Apr 23 19:26:58 2021, Koji, Update, PSL, HEPA speed lowered
|
I believe that there is an internal setting for the minimum flow, so the flow is not linear ("0%" is not zero), but we should mark this flow
speed once you find this is sufficiently low for the locking too. |
|
Fri May 14 17:45:05 2021, rana, Update, PSL, HEPA speed raised
|
The PSL was too hot, so I turned on the south HEPA on the PSL. The north one was on and the south one was off (or so slow as to be inaudible and no vibration,
unlike the north one). Lets watch the trend over the weekend and see if the temperature comes down and if the PMC / WFS variations get less. Fri May 14
17:46:26 2021 |
|
Tue May 18 00:52:38 2021, rana, Update, PSL, HEPA speed raised
|
Looks like the fan lowered the temperature as expected. Need to get a few more days of data to see if its stabilized, or if that's just a fluke.
The vertical line at 00:00 UTC May 18 is about when I turned the fans up/on. |
|
Tue May 18 20:26:11 2021, rana, Update, PSL, HEPA speed raised
|
Fluke. Temp fluctuations are as usual, but the overall temperature is still lower. We ought to put some temperature sensors
at the X & Y ends to see what's happening there too. |
|
Thu Apr 22 15:15:26 2021, gautam, Update, PSL, PMC transmission
|
I was a bit surprised by these numbers suggesting the PMC transmission is only 50-60%. I went to the table today and confirmed that it is more like 85%
(1.3 W in, 1.1 W transmitted, both numbers from with the FieldMate power meter), as I claimed
in 2019. Even being conservative with the power meter errors, I think we can be confident T_PMC will be >80% (modulo any thermal effects with higher |
|
Thu Apr 22 15:34:54 2021, Anchal, Update, PSL, PMC transmission
|
Koji mentioned that the mode of the laser is different for lower diode currents. So that might be the reason why we got less transmission at the low
input power but more afterward. |
|
Sat May 15 12:39:54 2021, gautam, Update, PSL, NPRO tripped/switched off
|
The NPRO has been off since ~1AM this morning it looks like. Is this intentional? Can I turn it back on (or at least try to)? The interlock signal we are
recording doesn't report getting tripped but I think this has been the case in the past too. |
|
Fri May 14 03:29:50 2021, Koji, Update, Electronics, HV Driver noise test with the new HV power supply from Matsusada
|
I believe I did the identical test with the one in [40m ELOG 15786]. The + input of PA95
was shorted to the ground to exclude the noise from the bias input. The voltage noise at TP6 was measured with +/-300V supply by two HP6209 and two Matsusada
R4G360. |
|
Thu Apr 29 11:51:27 2021, Anchal, Summary, LSC, Start of measuring IMC WFS noise contribution in ar cavity length noise
|
Tried locking the arms
Ran IFO > Configure > ! (YARM) > Restore YARM. Nothing happened.
Trying to align through tip-tilt:
Previous
values: TT1: PIT: -1.7845, YAW: -0.2775; TT2: PIT: -1.3376, YAW: -0.0436
Couldn't get flashing of light in the arms at all.
Restored |
|
Thu Apr 29 15:11:33 2021, gautam, Update, CDS, RFM
|
The problem here was that the RFM errors cropped up again - seems like it started ~4am today morning judging by TRX trends. Of course without the triggering
signal the arm cavity couldn't lock. I rebooted everything (since just restarting the rfm senders/receivers did not do the trick), now arm locking
works fine again. It's a bit disappointing that the Rogue Master setting did not eliminate this problem completely, but oh well... |
|
Thu Apr 29 17:43:16 2021, Koji, Update, CDS, RFM
|
The other day I felt hot at the X end. I wondered if the Xend A/C was off, but the switch right next to the SP table was ON (green light).
I could not confirm if the A/C was actually blowing or not. |
|
Thu Apr 29 17:43:48 2021, Anchal, Update, CDS, F2A Filters double check
|
I double checked today and the F2A filters in the output matrices of MC1, MC2 and MC3 in the POS column are ON. I do not get what SDF means? Did we need
to add these filters elsewhere?
Quote:
|
|
Fri Apr 30 00:20:30 2021, gautam, Update, CDS, F2A Filters double check
|
The SDF system is supposed to help with restoring the correct settings, complementary to burt. My personal opinion is that there is no need to commit
these filters to SDF until we're convinced that they help with the locking / noise performance.
Quote:
|
|
Thu Apr 29 17:51:19 2021, Anchal, Summary, LSC, Start of measuring IMC WFS noise contribution in arm cavity length noise
|
t Both arms were locked simply by using IFO > Configure > ! (YARM) > Restore YARM. I had to use ASS to improve the TRX/TRY to ~0.95.
I measured C1:LSC-XARM_IN1_DQ and C1:LSC-YARM_IN1_DQ while injecting band limited noise in C1:IOO-WFS1_PIT_EXC using uniform noise with amplitude
1000 along with filter defined by string: cheby1("BandPass",4,1,80,100). I calibrated the control arms signals by 2.44 nm/cts calibration factor |
|
Fri Apr 30 00:18:40 2021, gautam, Summary, LSC, Start of measuring IMC WFS noise contribution in arm cavity length noise
|
This is the actuator calibration. For the error point calibration, you have to look at the filter in the calibration model. I think
it's something like 8e-13m/ct for POX and similar for POY.
Quote:
|
|
Mon May 3 09:14:01 2021, Anchal, Paco, Update, LSC, IMC WFS noise contribution in arm cavity length noise
|
Lock ARMs
Try IFO Configure ! Restore Y Arm (POY) and saw XARM lock, not YARM. Looks like YARM biases on ITMY and ETMY are not optimal, so we slide
C1:SUS-ETMY_OFF from 3.0 --> -14.0 and watch Y catch its lock.
Run |
|
Mon May 3 17:28:58 2021, Anchal, Paco, Rana, Update, LSC, IMC WFS noise contribution in arm cavity length noise
|
Rana came and helped us figure us where to inject the noise. Following are the characteristics of the test we did:
Inject normal noise at C1:IOO-MC1_PIT_EXC using AWGGUI.
Excitation amplitude of 54321 in band 12-37Hz with Cheby1 8th order
bandpass filter with same limits.
Look at power spectrum of C1:IOO-MC_F_DQ, C1:IOO-WFS1-PIT_OUT_DQ and the C1:IOO-MC1_PIT_EXC itself.
Increased |
|
Tue May 4 11:43:09 2021, Anchal, Paco, Update, LSC, IMC WFS noise contribution in arm cavity length noise
|
We redid the WFS noise injection test and have compiled some results on noise contribution in arm cavity noise and IMC frequency noise due to angular
noise of IMC.
Attachment 1: Shows the calibrated noise contribution from MC1 ASCPIT OUT to ARM cavity length noise and IMC frequency |
|
Fri May 7 11:54:02 2021, Anchal, Paco, Update, LSC, IMC WFS noise contribution in arm cavity length noise
|
We today measured the calibration factors for XARM_OUT and YARM_OUT in nm/cts and replotted our results from 16117
with the correct frequency dependence.
Calibration of XARM_OUT and YARM_OUT |
|
Mon May 10 18:19:12 2021, Anchal, Paco, Update, LSC, IMC WFS noise contribution in arm cavity length noise, Corrections
|
A few corrections to last analysis:
The first plot was not IMC frequency noise but actually MC_F noise budget.
MC_F is frequency noise in the IMC FSS loop
just before the error point where IMC length and laser frequency is compared.
So, MC_F (in high loop gain frequency region upto 10kHz) is simply |
|
Wed May 12 10:53:20 2021, Anchal, Paco, Update, LSC, PSL-IMC PDH Loop and XARM PDH Loop diagram
|
Attached is the control loop diagram when main laser is locked to IMC and a single arm (XARM) is locked to the transmitted light from IMC.
Quote:
I'll post a clean loop diagram soon to make this loopology clearer.
|
|
Mon May 10 10:57:54 2021, Anchal, Paco, Summary, Calibration, Using ALS beatnote for calibration, test
|
Test details:
We locked both arms and opened the shutter for Yend green laser.
After toggling the shutter
on.off, we got a TEM00 mode of green laser locked to YARM.
We then cleared the phase Y history by clicking "CLEAR PHASE Y HISTROY"
on C1LSC_ALS.adl (opened from sitemap > ALS > ALS).
We sent excitation signal at ITMY_LSC_EXC using awggui at 43Hz, 77Hz and 57Hz.
We |
|
Thu May 6 16:13:39 2021, Anchal, Summary, IMC, Angular actuation calibration for IMC mirrors
|
Here's my first attempt at doing angular actuation calibration for IMC mirrors using the method descibed in /users/OLD/kakeru/oplev_calibration/oplev.pdf
by Kakeru Takahashi. The key is to see how much is the cavity mode misaligned from the input mode of beam as the mirrors are moved along PIT or YAW.
There two possible kinds of mismatch: |
|
Wed May 5 13:05:07 2021, Chub, Update, General, chassis delivery from De Leone
|
Assembled chassis from De Leone placed in the 40 Meter Lab, along the west wall and under the display pedestal table. The leftover parts are in
smaller Really Useful boxes, also on the parts pile along the west wall. |
|
Mon May 3 18:59:58 2021, Anchal, Summary, General, Weird gas leakagr kind of noise in 40m control room
|
For past few days, a weird sound of decaying gas leakage comes in the 40m control room from the south west corner of ceiling. Attached is an audio capture.
This comes about every 10 min or so. |
|
Mon May 3 23:28:56 2021, Koji, Summary, General, Weird gas leakagr kind of noise in 40m control room
|
I also noticed some sound in the control room. (didn't open the MP3 yet)
I'm afraid that the hard disk in the control room iMac is dying.
|
|
Mon Apr 19 09:17:51 2021, Jordan, Update, VAC, Empty N2 Tanks
|
When I came into the lab this morning, I noticed that both N2 tanks were empty. I had swapped one on Friday (4-16-21) before I left the lab. Looking
at the logs, the right tank (T2) sprung a leak shortly shortly after install. I leak checked the tank coupling after install but did not see a leak. There
could a leak further down the line, possibly at the pressure transducer. |
|
Wed Apr 21 12:56:00 2021, Jordan, Update, VAC, Empty N2 Tanks
|
Installed T2 today, and leaked checked the entire line. No issues found. It could have been a bad valve on the tank itself. Monitored T2 pressure for
~2 hours to see if there was any change. All seems ok.
Quote:
|
|
Wed Apr 28 11:31:40 2021, Jon, Update, VAC, Empty N2 Tanks
|
I checked out what happened on c1vac. There are actually two independent monitoring codes running:
The interlock service, which monitors the line directly connected to the valves.
A seaparate convenience mailer, running
as a cronjob, that monitors the tanks.
The interlocks did not trip because the low-pressure delivery line, downstream of the dual-tank |
|
Mon Apr 26 18:52:52 2021, Anchal, Paco, HowTo, Computer Scripts / Programs, awg free slot
|
Today we had some trouble launching an excitation on C1:IOO-MC_LSC_EXC from awggui. The error read:
awgSetChannel:
failed getIndexAWG C1:SUS-MC2_LSC_EXC ret=-3 |
|
Tue Apr 13 20:45:16 2021, Yehonathan, Update, PSL, Laser amplifier
|
{Yehonathan, Rana}
We unpacked the content of the amplifier crate in front of the water fountain (see attachments). Inside we found:
1. Amplifier head. (attachment 1) |
|
Wed Apr 14 19:48:18 2021, gautam, Update, PSL, Laser amplifier
|
A couple of years ago, I got some info about the amplifier setup at the sites from Terra - sharing here in case there is some useful info in there (our setup will be rather different, but it looked to me like our Amp is a 2017 vintage and it may be that the
performance is not the same as reported in the 2019 paper). |
|
Thu Apr 15 09:46:24 2021, Yehonathan, Update, PSL, Laser amplifier
|
Some more relevant documents provided by Matt:
Phase III:70W amplifier integration at LIGO
70W amplifier External Shutter |
|
Fri Apr 16 18:21:36 2021, Yehonathan, Update, PSL, Laser amplifier
|
I surveyed a bit the 1X1/2 area to plan for the installation of the laser amplifier.
There is a vacancy at the bottom of 1X2 (attachment 1). I measured the dimensions of the diode box (DB) and it should fit. The optical fiber
bundle is 75m long and should reach the amplifier head on the table easily. |
|
Sun Apr 18 21:29:55 2021, rana, Update, PSL, Laser amplifier
|
Ideally, we put the chiller outside of the interferometer area. The PSL chiller used to be in the control room near the door by IMC REFL. We
could also put it in the drill press room.
Once we figure out a couple of places where the Diode Box can go, we can ask facilities to make the
appropriate power connections. They will have to eval the situation to figure out if the main power to the lab needs to be shut down.
Can we |
|
Wed Apr 21 11:09:57 2021, yehonathan, Update, PSL, Laser amplifier
|
I went to the TCS lab to take a look at the chillers lying around. I spotted two chillers:
1. Thermoflex1400 (attachment 1,2). Spec sheet.
2. Polyscience Recirculator 6000 series (attachment 3,4). Manual. |
|
Thu Apr 22 17:28:34 2021, Yehonathan, Update, PSL, Laser amplifier
|
According to the aLIGO 70W amplifier interlock concept the flow rate of the chiller should be between
5 and 40 l/min. The chillers I found in the TCS lab both have around 15 l/min flow rate so we should be fine in that regard.
Assuming that the power consumption of the diode box is ~800W and that the optical output power of the diode is ~ 300W of optical power, the |
|
Thu Apr 22 14:49:08 2021, gautam, Update, Computer Scripts / Programs, rossa added to RTS authorized keys
|
This is to facilitate running of scripts like the CDS reboot script, mx_stream restart, etc, from rossa, without being pwd prompted every time, whereas
previously it was only possible from pianosa. I added the public key of rossa to FB and the RT FE servers. I suppose I could add it to the Acromag servers
too, but I haven't yet. |
|
Thu Apr 22 01:42:38 2021, Koji, Summary, Electronics, HV Supply Comparison
|
New HV power supply from Company 'M' has been delivered. So I decided to compare the noise levels of some HV supplies in the lab. There are three
models from companies 'H', 'K', and 'M'.
The noise level was measured with SR785 via Gautam's HP filter with protection diodes. |
|
Wed Apr 21 05:48:47 2021, Chub, Update, General, PSL HEPA Maintenance
|
| Yikes! That's ONE filter. I'll get another from storage. |
|
Wed Apr 21 13:10:12 2021, Koji, Update, General, PSL HEPA Maintenance
|
It's probably too late to say but there are/were two boxes. (just for record)
|
|
Wed Apr 21 10:59:07 2021, rana, Summary, Cameras, note on new GigE cam @ 1064
|
| Note from Stephen on more sensitive Baslers. |
|
Wed Apr 21 00:08:15 2021, Koji, Update, PSL, PSL Table (sort of) covered / HEPA "chimney"
|
Shutdown Procedure:
PSL Shutter closed / MC Autolocker disabled / PSL mechanical shutter closed / Laser injection current turned to zero / Laser turn off (red button)
/ Laser key turned off |
|
Wed Apr 21 01:14:03 2021, Koji, Update, PSL, PSL Table (sort of) covered / HEPA "chimney"
|
I also located the (possible) HEPA filters in the lab. (Attachments 1~3)
Oh! This is NO-NO! We can't place anything in front of the mains breakers. (Attachment 2)
I relocated the objects (Attachment 3) |
|
Fri Apr 16 00:21:52 2021, Koji, Update, General, Glue Freezer completely frozen
|
I was looking at the laser head/amp and somehow decided to open the glue freezer. And it was stuck. I've managed to open it but the upper room was
completely frozen.
Some of the batteries were embedded in a block of ice. I think we should throw them out. |
|
Fri Apr 16 10:58:16 2021, Yehonathan, Update, General, Glue Freezer completely frozen
|
{Paco, Anchal, Yehonathan}
We emptied the fridge and moved the amplifier equipment on top of the amplifier crate. We unplugged the freezer and moved it out of the lab to
defrost (attachment). |
|
Fri Apr 16 19:07:31 2021, Yehonathan, Update, General, Glue Freezer completely frozen
|
There is still a huge chunk of unmelted ice in the fridge. I moved the content of that fridge in the main fridge and put "do not eat" warning
signs.
I returned the fridge to the lab and plugged it back in to prevent flooding. |
|
Mon Apr 19 10:52:27 2021, Yehonathan, Update, General, Glue Freezer completely frozen
|
{Anchal, Paco, Yehonathan}
We took the glue fridge outside. |
|
Mon Apr 19 19:40:54 2021, Yehonathan, Update, General, Glue Freezer completely frozen
|
{Paco, Yehonathan}
We broke the last chunk of ice and cleaned the fridge. We move the fridge back inside and plugged it into the wall. The glues were moved back
from the main fridge. |
|
Fri Apr 16 11:31:00 2021, rana, Update, elog, elog stuck ~10 AM today
|
| found it unresponsive. Restarted fine using procedure documented in wiki |
|
Thu Apr 15 18:33:39 2021, Koji, Update, CDS, More 16bit ADC adapter boards
|
We received 10x 16bit ADC adapter boards from Todd. S2100687~S2100696
The number of soldered resistors seems to be less than that on the schematics. They are related to duotone, so check if it's OK upon use. |
|
Wed Apr 7 22:48:48 2021, gautam, Update, IOO, Waveplate commissioning
|
Summary:
I spent an hour today evening checking out the remote waveplate operation. Basic remote operation was established 👍
. To run a test on the main beam (or any beam for that matter), we need to lay out some long cabling, and install the controller in a rack. I will work |
|
Tue Apr 13 17:47:07 2021, gautam, Update, IOO, Waveplate commissioning - software prepared
|
I spent some time today setting up a workable user interface to control the waveplate.
Created some EPICS database records at /cvs/cds/caltech/target/ESP300.db.
These are all soft channels. This required a couple of restarts of the modbus service |
|
Thu Apr 15 15:54:46 2021, gautam, Update, IOO, Waveplate commissioning - hardware installed
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[jordan, gautam]
We did the following this afternoon.
Disconnected the cable from the unused (and possibly not working) |
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Wed Apr 14 23:55:34 2021, gautam, Update, Electronics, HV Coil driver assembly
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I've occcupied the southernmost electronics bench for assembling the 4 production version HV coil driver chassis. I estimate it will take me 3 days,
and have left a sign indicating as much. Once the chassis assembly is done, I will need to occupy the northernmost bench where bench supplies are to run
some functionality tests / noise measurements, and so unless there are objections, I will move the Acromag box which has been sitting there. |
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Wed Apr 14 14:52:42 2021, gautam, Update, General, IFO State
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The C1:IFO-STATE variable is actually
a bunch (16 to be precise) of bits, and the byte they form (2 bytes) converted to decimal is what is written to the EPICS channel. It was reported on the
call today that the nominal value of the variable when the IMC is locked was "8", while it has become "10" today. In fact, this has |
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Wed Apr 14 16:46:24 2021, Anchal, Update, General, IFO State
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That makes sense. I assumed that IFO-STATE is configured as you have proposed it to be configured. This could be implemented in later.
Quote:
a better way would be to configure the EPICS record to automatically set / unset itself based on some diagnostic |
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Wed Apr 14 12:27:10 2021, gautam, Update, General, Lab left open again
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Once again, I found the door to the outside in the control
room open when I came in ~1215pm. I closed it. |
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Wed Apr 14 13:12:13 2021, Anchal, Update, General, Sorry, it was me
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| Sorry about that. It must be me. I'll make sure it doesn't happen again. I was careless to not check back, no further explanation. |
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Wed Apr 14 15:30:29 2021, rana, Update, General, Sorry, it was me
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Maybe tighten the tensioner on the door closer so that it closes by itself even in the low velocity case. Or maybe just use the front door like everyone
else? |
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Wed Mar 17 09:05:01 2021, Paco, Anchal, Configuration, Computers, 40m Control Room Changes
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Switched positions of allegra and donatella.
While doing so, the hdmi cable previously used by donatella snapped. We replaced this
cable by another unused cable we found connected only on one end to rossa. We should get more HDMI cables if that cable was in use for some other purpose.
Paco
bought a bluetooth speaker/mic that is placed infront of allegra and it's usb adapter is connected to iMac's keyboard in the bottom. With the new |
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Wed Apr 14 13:16:20 2021, Anchal, Configuration, Computers, 40m Control Room Changes
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I have confirmed that the old two monitors' backlighting is not working. One can see the impression of the display without any brightness
on them. Both old monitors are on the shelf behind.
Today we got a monitor and mouse from Mike. I had to change /etc/default/grub GRUB_GFXMODE
to 1920x1200@30 on allegra for it to work with the(any) monitor.
Allegra is Debian 10 with latest cds-workstation installed on it. It is a good |
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Tue Apr 13 19:24:45 2021, gautam, Update, PSL, High power operations
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We (rana, yehonathan and i) briefly talked about having high power going into the IFO. I worked on some calcs a couple of years ago, that are summarized
here. There is some discussion in the linked page about how much power we even
need. In summary, if we can have |
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Mon Apr 12 08:32:54 2021, Anchal, Paco, Summary, PSL, PMC unlocked at 2pm on Sunday; ~ Restored
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PMC lost lock between 21:00 and 22:00 UTC on April 11th as seen in the summary pages:
https://nodus.ligo.caltech.edu:30889/detcharsummary/day/20210411/psl/#gallery-4
That's between 2pm and 3pm on Sunday for us. We're not sure what caused it. We will attempt to lock it back. |
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Mon Apr 12 18:34:26 2021, Yehonathan, Summary, PSL, PMC unlocked at 2pm on Sunday; ~ Restored
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PMC lost lock again at around 16:00 April 12. I was able to lock it again but the transmission is only 0.6 now and REFL is 0.14.
Rana
came in and realigned the PMC stirring mirrors. Now the transmission is 0.757V, and the REFL is 0.03V. |
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Thu Apr 8 20:58:17 2021, Koji, Update, CDS, ADC adapter boards assembly
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| 5x 16bit ADC adapter boards (D0902006) assembled. |
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Wed Apr 7 13:07:03 2021, Jordan, Update, SUS, CoM on 3"->2" Adapter Ring for SOS
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Adding the chamfer around the edge of the optic ring did not change the center of mass relative to the plane from the suspension wires.
The CoM was .0003" away from the plane. Adding the chamfer moved it closer by .0001". See the attached photo.
I've also attached the list of the Moments of Inertia of the SOS Assembly. |
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Wed Apr 7 02:50:49 2021, Koji, Update, SUS, Flange Inspections
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Basically I went around all the chambers and all the DB25 flanges to check the invac cable configurations. Also took more time to check the coil Rs and
Ls.
Exceptions are the TTs. To avoid unexpected misalignment of the TTs, I didn't try to disconnect the TT cables from the flanges. |
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Thu Oct 15 20:00:23 2020, Koji, Summary, General, HEPA AC cord replacement
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The AC cord from the PSL HEPA variac to the junction box was replaced.
Now the HEPA is running at 70%
Showed up at the 40m at 7pm |
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Thu Apr 1 23:55:33 2021, Koji, Summary, General, HEPA AC cord replacement
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I think the PSL HEPA (both 2 units) are not running. The switches were on. And the variac was changed
from 60% to 0%~100% a few times but no success.
I have no troubleshooting power anymore today. The main HEPA switch was turned off. |
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Fri Apr 2 15:17:23 2021, gautam, Summary, General, HEPA AC cord replacement
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From the last failure, I had ordered 2 extra capacitors (they are placed on top of the PSL enclosure above where the capacitors would normally be installed).
If the new capacitors lasted < 6months, may be symptomatic of some deeper problem though, e.g. the HEPA fans themselves need replacing. We don't
really have a good diagnostic of when the failure happened I guess as we don't have any channel recording the state of the fans. |
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Tue Apr 6 21:17:04 2021, Koji, Summary, General, PSL HEPA investigation
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- Last week we found both of the PSL HEPA units were not running.
- I replaced the capacitor of the north unit, but it did not solve the issue. (Note: I reverted the cap back later)
- It was found that the fans ran if the variac was removed from the chain. |
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Mon Apr 5 22:26:01 2021, gautam, Update, LSC, PRMI 1f locking (no ETMs) recovered
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Since it seems like the entire electronics chain has no obvious failure, I decided to compensate for the apparent increased optical gain by turning the
flat whitening gain down from +18dB to 0dB. Then, after some fiddling around with alignment, settings etc, I was able to lock the PRMI once again, with
the ETMs misaligned, using REFL55_I to sense PRCL, and REFL55_Q to sense MICH. Some sensing matrices attached. Some notes: |
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Mon Apr 5 08:25:59 2021, Anchal, Paco, Update, General, Restore MC from early quakes
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[Paco, Anchal]
Came in a little bit after 8 and found the MC unlocked and struggling to lock for the past 3 hours. Looking at the SUS overview, both MC1 and
ITMX Watchdogs had tripped so we damped the suspensions and brought them back to a good state. The autolocker was still not able to catch lock, so we cleared |
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Sat Apr 3 00:42:40 2021, gautam, Update, LSC, PRFPMI locking with half input power
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Summary:
I wanted to put my optomechanical instability hypothesis to the test. So I decided
to cut the input power to the IMC by ~half and try locking the PRFPMI. However, this did not improve the stability of the |
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Fri Apr 2 01:26:41 2021, gautam, Update, Electronics, REFL55 chain checkout again, seems fine
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[koji, gautam]
Summary:
We could not find problems with any individual piece of the REFL55 electronics chain, from photodiode to ADC. Nevertheless, |
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Wed Mar 31 00:40:32 2021, Koji, Update, Electronics, Electronics Packaging for assembly work
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I've worked on packing the components for the following chassis
- 5 16bit AI chassis
- 4 18bit AI chassis |
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Thu Apr 1 18:16:28 2021, Koji, Update, Electronics, Electronics Packaging for assembly work
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All small components are packed in the boxes. They are ready to ship.
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Thu Apr 1 00:50:06 2021, gautam, Update, SUS, PRMdiag
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I spent some time investigating the PRM this evening, trying out some of the stuff we discussed in the meeting.
I used one of the SUS lockin oscillator to drive the butterfly mode (UL=+1, UR=-1, LL=-1, LR=+1) of the optic, @4.45 Hz, Amplitude=450cts (Oplev
loops were engaged during the measurement).
Used the sensing matrix infrastructure to demodulate the Oplev PIT/YAW error signals, using the |
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Thu Feb 18 20:24:48 2021, Koji, Summary, Electronics, A bunch of electronics received
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Todd provided us a bunch of electronics. I went to Downs to pick them up this afternoon and checked the contents in the box. Basically, the boxes are
pretty comprehensive to produce the following chassis
8 HAM-A coil driver chassis
7 16bit Anti-Aliasing chassis
4 18bit Anti-Imaging chassis
5 16bit Anti-Imaging |
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Sat Feb 20 10:01:48 2021, gautam, Summary, Electronics, A bunch of electronics received
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| Will we also be receiving the additional 34 Satellite Amplifier PCBs? |
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Sat Feb 20 16:46:17 2021, Koji, Summary, Electronics, A bunch of electronics received
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We received currently available sets. We are supposed to receive more coil drivers and sat amps, etc. But they are not ready yet.
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Fri Mar 5 00:53:09 2021, Koji, Summary, Electronics, A bunch of electronics received
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Received additional front/rear panels. Updated the original entry and Wiki [Link]
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Fri Mar 5 15:03:28 2021, gautam, Summary, Electronics, A bunch of electronics received
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The PCBs for the D1002593 BIO I/F (5pcs ea of D1001050 and D1001266)
were received (from JLCPCB) today. idk what the status of the parts (digikey?) is.
Quote:
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Fri Mar 5 15:32:53 2021, Koji, Summary, Electronics, A bunch of electronics received
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| The parts will be ordered by Koji The components for the additional BIO I/F have been ordered. |
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Wed Mar 31 03:56:37 2021, Koji, Summary, Electronics, A bunch of electronics received
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| We have received 9x 18bit DAC adapter boards (D1000654) |
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Wed Mar 24 15:24:13 2021, gautam, Update, LSC, Notes on tests
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For my note-taking:
Lock PRMI with ITMs as the MICH actuator. Confirm that the MICH-->PRCL contribution cannot be nulled. ✅
[15960]
Lock PRMI on REFL165 I/Q. Check if transition can be made smoothly to (and |
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Wed Mar 24 22:54:49 2021, gautam, Update, LSC, New day, new problems
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I thought I'd get started on some of the tests tonight. But I found that this problem
had resurfaced. I don't know what's so special about the REFL55 photodiode - as far as I can tell, other photodiodes at the REFL port are running
with comparable light incident on it, similar flat whitening gain, etc etc. The whitening electronics are known to be horrible |
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Mon Mar 29 19:32:46 2021, gautam, Update, LSC, REFL55 whitening checkout
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I repeated the usual whitening board characterization test of:
driving a signal (using awggui) into
the two inputs of the whitening board using a spare DAC channel available in 1Y2
demodulating the response using the LSC sensing matrix infrastructure
Stepping |
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Thu Mar 25 18:05:04 2021, gautam, Update, Electronics, Stuffed HV coil drivers received from Screaming Circuits
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I think the only part missing for assembly now are 4 2U chassis. The PA95s need to be soldered on as well (they didn't arrive in time to send to
SC). The stuffed boards are stored under my desk. I inspected one board, looks fine, but of course we will need to run some actual bench tests to be sure. |
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Thu Mar 25 17:39:28 2021, gautam, Update, Computer Scripts / Programs, Spot position measurement scripts "modernized"
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I want to measure the spot positions on the IMC mirrors. We know that they can't be too far off centerBasically I did the bare minimum to get these
scripts in /opt/rtcds/caltech/c1/scripts/ASS/MC/
running on rossa (python3 mainly). I confirmed that I get some kind of spot measurement from this, but not sure of the data quality / calibration to convert |
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Fri Mar 12 03:08:23 2021, Koji, Summary, SUS, Coil Rs & Ls for PRM/BS/SRM
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Summary
Per Gautam's request, I've checked the coil resistances and inductances.
PRM/BS/SRM coils were tested.
All the PRM coils look well-matched in terms of the inductance. Also, I didn't find a significant |
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Fri Mar 12 12:32:54 2021, gautam, Summary, SUS, Coil Rs & Ls for PRM/BS/SRM
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For consistency, today, I measured both the BS and PRM actuator balancing using the same technique and don't find as serious an imbalance for the
BS as in the PRM case. The Oplev laser source is common for both BS and PRM, but the QPDs are of course distinct.
BTW, I thought the expected resistance of the coil windings of the OSEM is ~13 ohms, while the BS/PRM OSEMs report ~1-2 ohms. Is this okay? |
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Fri Mar 12 13:01:43 2021, rana, Summary, SUS, Coil Rs & Ls for PRM/BS/SRM
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| ugh. sounds bad - maybe a short. I suggest measuring the inductance; thats usually a clearer measurement of coil health |
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Fri Mar 12 13:48:53 2021, gautam, Summary, SUS, Coil Rs & Ls for PRM/BS/SRM
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I didn't repeat Koji's measurement, but he reports the expected ~3.2mH per coil on all the BS and PRM coils.
Quote:
ugh. sounds bad - maybe a short. I suggest measuring the inductance; thats usually a clearer measurement of coil |
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Thu Mar 25 16:02:15 2021, gautam, Summary, SUS, Repeated measurement of coil Rs & Ls for PRM/BS
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Method
Since I am mainly concerned with the actuator part of the OSEM, I chose to do this measurement at the output cables for the coil drivers in 1X4.
See schematic for pin-mapping. There are several parts in between my measurement |
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Tue Mar 16 14:37:36 2021, Yehonathan, Update, BHD, SOS SmCo magnets Inspection
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In the cleanroom, I opened the nickel-plated SmCo magnet box to take a closer look. I handled the magnets with tweezers. I wrapped the tips of the tweezers
with some Kapton tape to prevent scratching and magnetization.
I put some magnets on a razor blade and took some close-up pictures of the face of the magnets on both sides. Most of them look like attachment |
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Wed Mar 17 14:40:39 2021, Yehonathan, Update, BHD, SOS SmCo magnets Inspection
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Continuing with envelope number 2
Magnet number
Magnetic field (kG)
1
2.89
2
2.85
3
2.92
4
2.75
5
2.95
6
2.91
7
2.93
8
2.9
9
2.93
10
2.9
11
2.85
12
2.89
13
2.85
14
2.88
15
2.92
16
2.75
17
2.97
18
2.88
19
2.85
20
2.87
21
2.93
22
2.9
23
2.9
24
2.89
25
2.88
26
2.8 |
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Thu Mar 25 14:58:16 2021, Yehonathan, Update, BHD, SOS SmCo magnets Inspection
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Redoing magnet measurement of envelope 1:
Magnet
#
Max Magnetic Field (kG)
1
2.89 |
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Mon Mar 22 16:29:17 2021, gautam, Update, ASC, Some prep for AS WFS commissioning
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Added rough cts2mW calibration filters to the quadrants, see Attachment
#1. The number I used is:
0.85 A/W * 500 V/A |
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Sun Mar 21 19:31:29 2021, rana, Summary, Electronics, RTL-SDR for monitoring RF noise / interference
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When we're debugging our RF system, either due to weird demod phases, or low SNR, or non-stationary noise in the PDH signals, its good to have some
baseline measurements of the RF levels in the lab.
I got this cheap USB dongle (RTL-SDR.COM) that seems to be capable of this and also has a bunch of open source code on GitHub to support it. |
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Thu Mar 18 21:37:59 2021, rana, Update, LSC, PRMI investigations: what IS the matrix??
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Locked PRMI several tmes after Gautam setup. Easy w IFO CONFIG screen
tuned up alignment
Still POP22_I doesn't go above ~111, so not triggering the loops. Lowered triggers
to 100 (POP22 units) and it locks fine now. |
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Fri Mar 19 11:18:25 2021, gautam, Update, LSC, PRMI investigations: what IS the matrix??
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From Finesse simulation (and also analytic calcs), the expected PRCL optical gain is ~1 MW/m (there is a large uncertainty, let's say a factor
of 5, because of unknown losses e.g. PRC, Faraday, steering mirrors, splitting fractions on the AP table between the REFL photodiodes). From the same simulation,
the MICH optical gain in the Q-phase signal is expected to be a factor of ~10 smaller. I measured |
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Fri Mar 19 22:24:54 2021, gautam, Update, LSC, PRMI investigations: what IS the matrix??
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I did all these checks today.
Quote:
I will check (i) REFL55 transimpedance, (ii) cable loss between AP table and 1Y2 and (iii) is the beam well centered |
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Fri Mar 19 15:31:56 2021, Aidan, Update, Computers, Activated MATLAB license on donatella
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| Activated MATLAB license on donatella |