In my calculation of the digital filters of the optical transfer functions the carrier light is resonant in coupled cavities and the sidebands are resonant in recycling cavities (provided that macroscopic lengths are chosen correctly which I assumed).
Carrier and SB (f2) shouldn't be resonant at the same time in the SRC-arms coupled cavity. No additional filtering of the GW signal is wanted.
The SRC macroscopic length is chosen to be = c / f2 - rather than = [ (n+1/2) c / (2*f2) ] - accordingly to that purpose.
I calculated the frequency of the double cavity pole for the 40m SRC-arm coupled cavity.
w_cc = (1 + r_srm)/(1- r_srm) * w_c
where w_c is the arm cavity pole angular frequency [w_c = w_fsr * (1-r_itm * r_etm)/sqrt(r_itm*r_etm) ]
I found the pole at about 160KHz. This number coincides with what I got earlier with my optickle model configured and tuned as I said in my previous entry. See attachments for plots of transfer functions with 0 and 10pm DARM offsets, respectively.
I think the resonance at about 20 Hz that you can see in the case with non-zero DARM offset, is due to radiation pressure. Koji suggested that I could check the hypothesis by changing either the mirrors' masses or the input power to the interferometer. When I did it frequency and qualty factor of the resonance changed, as you would expect for a radiation pressure effect.
This gave me more confidence about my optickle model of the 40m. This is quite comforting since I used that model other times in the past to calculate several things (i.e. effects of higher unwanted harmonics from the oscillator, or, recently, the power at the ports due to the SB resonating in the arms).
Here's the gist of the requirements on the 5x frequency multiplier for the upgrade (see attachemnt - despite the preview down here in the elog, they're 3 pages).
An extended version is available on the wiki.
A more complete document is under work and will soon be available on the wiki as well.
Set up gwsumm on optimus and generated summary pages from both L1 and C1 data. Still a few manual steps need to be taken during generation, not fully automated due to some network/username issues. nds2 now working from optimus after restarting nds2 server.
Bob, Callum and Daphen noted that our keeping a JDSU HeNe (max power <4mW) is against somebody's SOP. So I cleared everything that relates to 40m SOS suspending to the bottom shelf of the 2nd cabinet in the cleanroom (the back set of cabinets nearest the flow benches). The door has a nifty label. Things that are in there include:
QPD and micrometer mount
microscope and micrometer mount
Al beam block
Magnet gluing fixture
dumbbell gluing fixture
The electronics that we use (HeNe's power supply, 'scope, QPD readout) are still on the roll-y thing under the flow bench.
These are all priority action items need to be done before I come back (in mid-September).
BE PREPARED FOR THE FULL LOCK!
- Prepare and install tip-tilts -JAMIE
- Adjust IP-ANG -JAMIE, JENNE, KOJI
- Make sure there's no clipping. Start from MC centering -JAMIE, JENNE, KOJI
- Make ASS and A2L work -JENNE, JAMIE
- Better MC spot position measurement script(see the last sentence in elog #6892) -JENNE
- Daily beam spot measurements for IFO, just like MC -JENNE
- ASS for green using PZT steering mirrors on end table -JENNE
- Modeling of phase tracking ALS -JAMIE
- PZT mounts for PSL and ALS beams -JENNE, KOJI
- Add temperature sensors for end lasers to CDS slow channels -JENNE
- Put green trans camera, GTRY PD, and GTRX PD on PSL table -JENNE
- Better beat box; include comparators, frequency dividers, and whitening filters -JAMIE, KOJI
- Adjust servo gain/filters of end green PDH lock (reduce frequency noise) -JENNE
- Add on/off switch, gain adjuster, etc to CDS for end green PDH lock -JENNE, JAMIE
- Find why and reduce 3 Hz motion -JENNE
- Simulation of PRMI with clipping -YUTA
- Alignment tolerance of PRMI -YUTA
Koji pointed out during the group meeting that I should compensate for local tilt when I move the beam around the mirror for calculating the loss map.
So I did.
Also, I made a mistake earlier by calculating the loss map for a much bigger (X7) area than what I thought.
Both these mistakes made it seem like the loss is very inhomogeneous across the mirror.
Attachment 1 and 2 show the corrected loss maps for ITMX and ETMX respectively.
The loss now seems much more reasonable and homogeneous and the average total arm loss sums up to ~ 22ppm which is consistent with the after-cleaning arm loss measurements.
I finished calculating the X Arm loss using first-order perturbation theory. I will post the details of the calculation later.
I calculated loss maps of ITM and ETM (attachments 1,2 respectively). It's a little different than previous calculation because now both mirrors are considered and total cavity loss is calculated. The map is calculated by fixing one mirror and shifting the other one around.
The losin total is pretty much the same as calculated before using a different method. At the center of the mirror, the loss is 21.8ppm which is very close to the value that was calculated.
Next thing is to try SIS.
The cavity modes , where q is the complex beam parameter and m,n is the mode index, are the eigenmodes of the cavity propagator. That is:
where is the mirror reflection matrix. At the 40m, ITM is flat, so . ETM is curved, so , where R is the ETM's radius of curvature.
is the Gouy phase.
is the free-space field propagator. When acting on a state it propagates the field a distance L.
The phase maps perturb the reflection matrices slightly so:
Where h_12 are the height profiles of the ITM and ETM respectively. The new propagator is
, where is the unperturbed propagator and
To find the perturbed ground state mode we use first-order perturbation theory. The new ground state is then
Where N is the normalization factor. The (0,1) and (1,0) modes are omitted because they can be zeroed by tilting the mirrors. Gouy phase of TEM00 mode is taken to be 0.
Some simplification can be made here:
The last step is possible since the beam parameter q matches the cavity.
The loss of the TEM00 mode is then:
I have a serious concern about this low angle scattering analysis:
Phase maps perturb the spatial mode of the steady-state of the cavity, but how is this different than mode-mismatch? The loss that I calculated is an overall loss, not roundtrip loss.
The only way I can think this can become serious loss is when the HOMs themselves have very high roundtrip loss. Attached is the modal power fraction that I calculated.
P-pol = purple
S-pol = red
The .graffle file for this is in the 40m SVN's omnigraffle dir/
I made a node to collect drawings/schematics for the 40m OMC, added the length drive for now. We should collect other stuff (TT drivers, AA/AI, mechanical drawings etc) there as well for easy reference.
Some numbers FTR:
I'm working on developing a full noise budget for the 40m. To that end, I'll use measurements from the GUR1 seismometer to characterize seismic noise. Without any unit calibration, I found the following spectrum,
To extract useful information from this data, I first used the calibration from "/users/Templates/Seismic-Spectra_121213.xml" to obtain the spectrum in [m / s / sqrt(Hz)].
calibrated_data = raw_data * 3.8e-09
I then divided each point in the power spectrum by the frequency of said point to obtain [m / sqrt(Hz)]. I don't think we can simply divide the whole spectrum by 40 meters to obtain [RIN / sqrt(Hz)], although that was my immediate intuition. Having power spectra of all the major noise contributions in units of [RIN / sqrt(Hz)] would make designing an appropriate filtering servo fairly straightforward.
We tried to locate the sixteen analog output channels we need to control the four tip-tilts (four coils on each). We have only 8 available channels on the C1SUS machine.
So we will have to plug-in a new DAC output card on one of the machines and it would be logical to do that on the C1IOO machine as the active tip-tilts are conceptually part of the IOO sub-system. We have to procure this card if we do not already have it. We have to make an interface between this card output and a front panel on the 1X2 rack. We may have to move some of the sub-racks on the 1X2 rack to accommodate this front panel.
We checked out the availability of cards (De-whitening, Anti-imaging, SOS coil drivers) yesterday. In summary: we have all the cards we need (and some spares too). As the De-whitening and Anti-imaging cards each have 8 channels, we need only two of each to address the sixteen channels. And we need four of the SOS coil drivers, one for each tip-tilt. There are 9 slots available on the C1IOO satellite expansion chassis (1X1 rack), where these eight cards could be accommodated.
There are two 25 pin feed-thoughs, where the PZT drive signals currently enter the BS chamber. We will have to route the SOS coil driver outputs to these two feed-throughs.
Inside the BS chamber, there are cables which carry the PZT signals from the chamber wall to the the table top, where they are anchored to a post (L- bracket). We need a 25-pin-to-25-pin cable (~2m length) to go from the post to the tip-tilt (one for each tip-tilt). And then, of course, we need quadrapus cables (requested from Rich) which fit inside each tip-tilt to go to the BOSEMs.
I am summarising it all here to give an overview of the work involved.
Action Items from Last Week:
Action Items this Week and LEAD PERSON:
Assemble and ship 4 TTs from LHO - SURESH
Prepare electronics for TTs (coil drivers) - JAMIE
In-air TT testing to confirm we can control / move TTs before we vent (starting in ~2 weeks) - SURESH
Connect TTs to digital system and controls, lay cables if needed - JAMIE with SURESH
OAF comparison plot, both online and offline, comparing static, adaptive and static+adaptive - DEN
Static-only OAF noise budget (Adaptive noise budget as next step) - DEN
Black glass: big baffle pieces to clean&bake, get small pieces from Bob, put into baskets, make new basket for 1" pieces, get to clean&bake - KOJI
IPPOS beam measurement - SURESH with JENNE
AS beam measurement (if beam is bright enough) - SURESH and JENNE
Mode matching calculations, sensitivity to MC waist measurement errors, PRM position - JENNE
Summary of IFO questions, measurements to take, and game plan - JENNE
Think up diagnostic measurement to determine mode matching to PRC while chambers are open, while we tweak MMT - JAMIE, JENNE, KOJI, SURESH
Arm cavity sweeps, mode scan - JENNE
Align AS OSA (others?) - JENNE
Investigate PRMI glitches, instability (take PRM oplev spectra locked, unlocked, to see if PRM is really moving) - KOJI, JENNE, DEN
Connect up beatbox for Xarm use - KOJI with JENNE
Build amplifiers for new small microphones - DEN
Black glass: to clean&bake - KOJI
Scattered light measurement at the end stations: design / confirmation of the mechanical parts/optics/cameras - JAN
Upgrade Rossa, Allegra to Ubuntu, make sure Dataviewer and DTT work - JAMIE
I'm combining the IFO check-up list (elog 6595) and last week's action items list (elog 6597). I thought about making it a wiki page, but this way everyone has to at least scroll past the list ~1/week.
Feel free to cross things out as you complete them, but don't delete them. Also, if there's a WHO?? and you feel inspired, just do it!
Dither-align arm to get IR on actuation nodes, align green beam - JENNE
Arm cavity sweeps, mode scan - JENNE
ASS doesn't run on Ubuntu! or CentOS Fix it! - JENNE, JAMIE's help
Input matricies, output filters to tune SUS. check after upgrade. - JENNE
POX11 whitening is not toggling the analog whitening??? - JAMIE, JENNE, KOJI
THE FULL LIST:
cd /opt/rtcds/caltech/c1/burt/autoburt/today/ -
Align Ygreen beam - JENNE, YUTA
Arm cavity sweeps, mode scan - JENNE, YUTA
ASS doesn't run on Ubuntu! or CentOS Fix it! - YUTA, JENNE, JAMIE's help
Decide on plots for 40m Summary page - DEN, STEVE, JENNE, KOJI, JAMIE, YUTA, SURESH, RANA, DUNCAN from Cardiff/AEI
Look into PMC PZT drift - PZT failing? Real MC length change? - JENNE, KOJI, YUTA
Yesterday I resurrected the 40m's LSC simPlant model, c1lsp. It is running on c1sim, a virtual, self-contained cymac that Chris and I set up for developing sim models (see 15997). I think the next step towards an integrated IFO model is incorporating the suspension plants. I am going to hand development largely over to Ian at this point, with continued support from me and Chris.
This model dates back to around 2012 and appears to have last been used in ~2015. According to the old CDS documentation:
Here XEP, YEP, and VSP are respectively the x-end, y-end, and vertex suspension plant models. I haven't found any evidence that these were ever fully implemented for the entire IFO. However, it looks like SUS plants were later implemented for a single arm cavity, at least, using two models named c1sup and c1spx (appear in more recent CDS documentation). These suspension plants could likely be updated and then copied for the other suspended optics.
To represent the optical transfer functions, the model loads a set of SOS filter coefficients generated by an Optickle model of the interferometer. The filter-generating code and instructions on how to use it are located here. In particular, it contains a Matlab script named opt40m.m which defines the interferferometer. It should be updated to match the parameters in the latest 40m Finesse model, C1_w_BHD.kat. The calibrations from Watts to sensor voltages will also need to be checked and likely updated.
For future reference, below are the steps followed to port this model to the virtual cymac.
$ cd ~/docker-cymac
$ ./start_cymac debug
The optional debug flag will print the full set of compilation messages to the terminal. If compilation fails, search the traceback for lines containing "ERROR" to determine what is causing the failure.
Accessing MEDM screens. Once the model is running, a button should be added to the sitemap screen (located at c1sim:/home/controls/docker-cymac/userapps/medm/sitemap.adl) to access one or more screens specific to the newly added model.
Custom-made screens should be added to c1sim:/home/controls/docker-cymac/userapps/medm/x1lsp (where the final subdirectory is the name of the particular model).
The set of available auto-generated screens for the model can be viewed by entering the virtual environment:
$ cd ~/docker-cymac
$ ./login_cymac #drops into virtual shell
# cd /opt/rtcds/tst/x1/medm/x1lsp #last subdirectory is model name
# ls -l *.adl
# exit #return to host shell
The sitemap screen and any subscreens can link to the auto-generated screens in the usual way (by pointing to their virtual /opt/rtcds path). Currently, for the virtual path resolution to work, an environment script has to be run prior to launching sitemap, which sets the location of a virtual MEDM server (this will be auto-scripted in the future):
$ cd ~/docker-cymac
$ eval $(./env_cymac)
One important auto-generated screen that should be linked for every model is the CDS runtime diagnostics screen, which indicates the success/fail state of the model and all its dependencies. T1100625 details the meaning of all the various indicator lights.
Added Matlab to the Docker machine. This should help immensely with workflow as well as keeping installed libraries consistent. Next step is outlining the project so coding is easier
Command to launch is: $ matlab &
From Jon just for bookkeeping:
Then in the Matlab command window, open the CDS parts library via:
Then open an RTCDS model (for example, here the LSC plant) via:
The x1SUSsim model on the docker was made in a more recent version of Simulink so I updated Matlab (see this)
I updated Matlab to 2021a so now the docker has 2020b and 2021a installed. This should also install Simulink 10.3 for the sus model to open. I used my account to activate it but I can change it over if I get a dedicated license for this. I am not sure what Jon did for the 2020b that he installed.
it is giving me "License error: -9,57" so I guess it didn't work... I will try to just make the model on the 2020b just so I have something.
I was able to fix the problem with the activation (using this).
I can now open the x1sussim.mdl file. It is trying to access a BSFM_MASTER Library that it doesn't seem to have. the other files don't seem to have any warnings though.
the simple suspension model can be found in home/controls/docker-cymac/userapps/c1simpsus.mdl on the docker system. This is where I will put my model. (right now it is just a copied file)
Also using Simulink on the docker is very slow. I think this is either a limit of the x2goclient software or the hardware that the docker is running on.
So I am stuck on how to add the control block to my model. I am trying to make it as simple as possible with just a simple transfer function for a damped harmonic oscillator and then the control block (see overview.png).
The transfer function I am using is:
For future generations: To measure the transfer function (to verify that it is doing what it says it is) I am using the discrete transfer function estimator block. To get a quick transfer function estimator Simulink program run ex_discrete_transfer_function_estimator in the Matlab command line. This works well for filters but it was hit or miss using the discrete transfer function.
The roadblock I am running into right now is that I can't figure out how to add the controller to the model. Not on an interpretation level but in a very straightforward "can I drag it into my model and will it just work" kind of way.
I am also a little confused as to exactly which block would do the controlling. Because I want to just use the x of the pendulum (its position) I think I want to use the suspension controls which come are connected to in the suspension plant model. But where exactly is it and how can I get the model? I can't seem to find it.
The controller would be in the c1sus model, and connects to the c1sup plant model. So the controller doesn't go in the plant model.
Both the controller and the plant can be modeled using a single filter module in each separate model as you've drawn, but they go in separate models.
I have attached the framework that I am using for the full system. Plantframework.pdf has the important aspects that I will be changed. Right now I am trying to keep it mostly as is, but I have disconnected the Optic Force Noise and hope to disconnect the Suspension Position Noise. The Optic Force Noise Block is additive to the signal so eliminating it from the system should make it less realistic but simpler. It can be added back easily by reconnecting it.
The next step is adding my plant response, which is simply the transfer function and measurement from the last post. These should be inserted in the place of the red TM_RESP in the model.
The TM_RESP block takes in a vector of dimension 12 and returns a vector of dimension 6. The confusing part is that the block does not seem to do anything. it simply passes the vector through with no changes. I'm not sure why this is the case and I am looking for documentation to explain it but haven't found anything. As to how a 12 vector turns into a 6 vector I am also lost. I will probably just disconnect everything but the x position.
I tried to just throw in my model (see Simple_Plant.pdf) and see what happened but the model would not let me add built-in blocks to the model. This is weird because all the blocks that I am adding are part of the basic library. My guess is that this mode will only accept blocks from the CDL library. I will either need to change my blocks to be made from blocks in the CDL library or maybe I can pass the signal out of the plant framework model then into my model then back to the plant framework model. I think this is just a Matlab thing that I don't know about yet. (Jon probably knows)
I have also attached an image of the controls model for reference. It looks like a mess but I'm sure there is a method. I won't get lost in going through it just assume it works... for now.
The next question I have been asking is how do I show that the system works. When anchal and I made a python simulation of the system, we tested it by seeing the evolution of the degrees of freedom over time given some initial conditions. We could see the pendulum propagating and some of the coupling between the DOFs. This is a fast and dirty way to check if everything is working and should be easy to add. I simply recorded the POS signal and graph it over time. Once we get to a state-space model we can test it by taking the transfer function, but since our plant is literally already just a transfer function there isn't much of a point yet.
Also, I need to add color to my Simple_Plant.pdf model because it looks really boring :(
A shared LIGO Data Grid (LDG) account was created for use by the 40m lab. The purpose of this account is to provide access to the LSC computer cluster resources for 40m-specific projects that may benefit from increased computational power and are not linked to any user in particular (e.g. the summary pages).
For further information, please see https://wiki-40m.ligo.caltech.edu/40mLDASaccount
There is BLANK VacControl_BAK.adl screen only.
I can move a valve by disconnecting it's solenoid power if it's position is normally open.
I will close V1 and check computer cable connections and move on with manual - hand disconnect ea valve to be moved into the right position for vent. Valve positions will be confirmed by looking manual indicators on valves.
The 40m vacuum envelope vent is completed with instrument grade air.
Valve configuration: chamber open, RGA is pumped through VM3 by TP3,
The 4 hrs vent plot at 3 torr/min rate.
Nitrogen was used from 1e-6 torr to 35 torr at intake pressure 14 PSI
The rest was filled with 5 cylinders of Instrument Grade Air at intake pressure 14 PSI
We can start opening chamber at 3 pm today
I've created a 40m Google account. Please post all the 40m related photos to this site. If you don't already have it, download Picasa to make this easier.
40m Installation Photos">
the password is in the usual password place.
As part of the initiative to get a good daily summary page for aLIGO commissioning, Josh is spearheading his Detector Characterization group to produce such web pages for the 40m.
They're starting out with this launching point and then we can add all kinds of other information and plots as we want (e.g. Vac, PEM, Weather, coffee status). If you have suggestions/ideas, just edit this entry and add them, or email Josh directly.
Link to the new 40m DCC Document Tree: E1200979
This is mostly a reminder to myself about what I discussed with Jay and Alex this morning.
The big black IO chassis are "almost" done. Except for the missing parts. We have 2 Dolphin, 1 Large and 1 Small I/O Chassis due to us. One Dolphin is effectively done and is sitting in the test stand. However, 2 are missing timing boards, and 3 are missing the boards necessary for the connection to the computer. The parts were ordered a long time ago, but its possible they were "sucked to one of the sites" by Rolf (remember this is according to Jay). They need to either track them down in Downs (possibly they're floating around and were just confused by the recent move), get them sent back from the sites, or order new ones (I was told by one person that the place they order from them notoriously takes a long time, sometimes up to 6 weeks. I don't know if this is exaggeration or not...). Other than the missing parts, they still need to wire up the fans and install new momentary power switches (apparently the Dolphin boards want momentary on/off buttons). Otherwise, they're done.
We are due another CPU, just need to figure out which one it was in the test stand.
6 more BIO boards are done. When I went over the plans with Jay, we realized we needed 7 more, not 6, so they're putting another one together. Some ADC/DAC interface boards are done. I promised to do another count here, to determine how many we have, how many we need, and then report that back to Jay before I steal the ones which are complete. Unfortunately, he did not have a new drawing for the ASC/vertex wiring, so we don't have a solid count of stuff needed for them. I'll be taking a look at the old drawings and also looking at what we physically have.
I did get Jay to place the new LSC wiring diagram into the DCC (which apparently the old one never was put in or we simply couldn't find it). Its located at: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=10985
I talked briefly with Alex, reminded him of feature requests and added a new one:
1) Single part representing a matrix of filter banks
2) Automatic generation of Simulated shared memory locations and an overall on/off switch for ADC/DACs
3) Individual excitation and test point pieces (as opposed to having to use a full filter bank). He says these already exist, so when I do the CVS checkout, I'll see if they work.
I also asked where the adl default files lived, and he pointed me at ~/cds/advLigo/src/epics/util/
In that directory are FILTER.adl, GDS_TP.adl, MONITOR.adl. Those are the templates. We also discovered the timing signal at some point was changed from something like SYS-DCU_ID to FEC-DCU_ID, so I basically just need to modify the .adl files to fix the time stamp channel as well. I basically need to do a CVS checkout, put the fixes in, then commit back to the CVS. Hopefully I can do that sometime today.
I also brought over 9 Contec DO-32L-PE boards, which are PCIe isolated digital output boards which do into the IO chassis. These have been placed above the 2 new computers, behind the 1Y6 rack.
40m CAD Project
fix Q of Vio2 filter in SUS. - JENNE
Switch power source for beatnote PD's amplifiers from temporary power supplies under PSL table to permanent taking the power from a rack.
ASS doesn't run on Ubuntu!
Put beatbox back, simultaneous arm ALS
Input matricies, output filters to tune SUS. check after upgrade.
POX11 whitening is not toggling the analog whitening???
Look into PMC PZT drift - PZT failing? Real MC length change?
Vent planning / organization
THE FULL LIST:
Audio system for the signals!!!! Even a crappy one!
Input matricies, output filters to tune SUS. Check after upgrade.
Fix occasional common-mode power transient in the arm transmissions. Probably an alignment thing. Would ISS help?
Drift of the green incident axis -> Assess the amount of the drift / replace the mount
Calibration of POP22 / AS110
PMC/IMC/ARM characterization (loss, finesse, reflectivity, etc)
Arm cavity sweeps, mode scan
Align AS OSA (others?)
Investigate PRMI glitches, instability
PZT or Picomotor mounts for PSL/ALS beams
ALS on the both arm simultaneously / common / diff ALS scripts
Measure green locking (Aux laser to arm) transfer functions, residual spectra
Measure oplev spectra while locking Xgreen - see if the optics are particularly noisy
Measure Xarm residual motion using POX while ALS is engaged.
Fix Vio2 filter modules on SUS
Switch power supply for amplifiers of beatnote signal to rack power
Add temp sensors for end lasers to CDS slow channels
Put windows / pickoffs on PSL table for (a) green trans camera, (b) GTRY, (c) GTRX
Capture OSA signals in CDS (the 'scope TDS1001B has a USB port in the back for connecting to the computer)
Transmon (arms) for high and low power
POX11 whitening is not toggling the analog whitening???
Install guardians to monitor EPICS values
Actuator noise level characterization (coil driver response in V/m & coil driver noise level V/rtHz)
Improvement of POP22/110/AS110 RF circuits?
Complete 40m overview screen - everything should be clickable with pseudo 3D icons
Script to generate a MEDM tree
Resurrect MEDM snapshots
New ! buttons on every screen, include wiki page
Add all screens to svn
Daily diagnosis of the MC spot positions (there must be something already...)
Daily/occasional adjustment of the incident axis on the MC
Panic button on Watchdog screen isn't working on Ubuntu
OPLEV/OSEM trending script before the IFO work for diagnosis. Put into 40m summary screen.
Auto-locker for arms
Auto-locker for PSL things
Diagnostic script for CDS - mx_stream, other stuff.
Make sure scripts are all svn-ed
If each video screen has a caption, that would be great
GUI interface of "videoswitch"
Ubuntu vs. CentOS
Upgrade Ottavia to Ubuntu, make sure connect to DTT, Dataviewer, AWG.
IPPOS beam measurement
AS beam measurement (if beam is bright enough)
Mode matching calculations, sensitivity to MC waist measurement errors, PRM position
Think up diagnostic measurement to determine mode matching to PRC while chambers are open, while we tweak MMT
Use sensoray to capture, measure beam mode at AS, POP
Scattered light measurement at the end stations: design / confirmation of the mechanical parts/optics/cameras
Align AUX laser into dark port
Assemble in-vac beam dumps - how many do we need?
OAF comparison plot, both online and offline, comparing static, adaptive and static+adaptive
Static-only OAF noise budget (Adaptive noise budget as next step)
Script for daily / weekly re-calculation of Wiener, post to elog if need changing
Prepare electronics for TTs (coil drivers)
In-air TT testing to confirm we can control / move TTs before we vent
Connect TTs to digital system and controls, lay cables if needed
Determine whether we need to add a new flange to OMC chamber
Opto Energy diode laser - purchase
Set everything up
Demod board for AS110 - so we can also have POP110?
As suggested last week, Hang and I have reviewed the A+ BHD status (DRD, CDD, and reviewers' comments) and compiled a list of key unanswered questions which could be addressed through Finesse analysis.
In anticipation of others helping with this modeling effort, we've tried to break questions into self-contained projects and estimated their level of difficulty. As you'll see, they range from beginner to Finesse guru.
I'm not sure what's going on today but we're seeing ~80% packet loss on the 40MARS wireless network. This is obviously causing big problems for all of our wirelessly connected machines. The wired network seems to be fine.
I've tried power cycling the wireless router but it didn't seem to help. Not sure what's going on, or how it got this way. Investigating...
Here's an example of the total horribleness of what's happening right now:
controls@rossa:~ 0$ ping 192.168.113.222
PING 192.168.113.222 (192.168.113.222) 56(84) bytes of data.
From 192.168.113.215 icmp_seq=2 Destination Host Unreachable
From 192.168.113.215 icmp_seq=3 Destination Host Unreachable
From 192.168.113.215 icmp_seq=4 Destination Host Unreachable
From 192.168.113.215 icmp_seq=5 Destination Host Unreachable
From 192.168.113.215 icmp_seq=6 Destination Host Unreachable
From 192.168.113.215 icmp_seq=7 Destination Host Unreachable
From 192.168.113.215 icmp_seq=9 Destination Host Unreachable
From 192.168.113.215 icmp_seq=10 Destination Host Unreachable
From 192.168.113.215 icmp_seq=11 Destination Host Unreachable
64 bytes from 192.168.113.222: icmp_seq=12 ttl=64 time=10341 ms
64 bytes from 192.168.113.222: icmp_seq=13 ttl=64 time=10335 ms
--- 192.168.113.222 ping statistics ---
35 packets transmitted, 2 received, +9 errors, 94% packet loss, time 34021ms
rtt min/avg/max/mdev = 10335.309/10338.322/10341.336/4.406 ms, pipe 11
Note that 10 SECOND round trip time and 94% packet loss. That's just beyond stupid. I have no idea what's going on.
I'm still seeing some problems with this - some laptops are losing and not recovering any connection. What's to be done next? New router?
We had the same problem yesterday. However the Vacuum Dedicated laptop worked with fewer disconnects. Christian is coming over this after noon to look at this issue.
This happened a few weeks ago and it recovered misteriously. Jamie did not understand it.
Temporary solution: I ssh'd to nodus from the 40m wifi network and was able to connect to the FE machines.This works but the bandwidth is limited this way as expected.
40m MARS network needs to be fixed.
Mike and Christian brought over a Mac laptop for surf Alex.
They power cycled the wireless router of 40Marsh and labtops are working. Seeing 75-80% signals on all 3 Dell lab top sisters at both end of the lab
i added my laptop's mac address to teh martian at port 13 today.
No personal laptop is allowed to the martian network. Only access to the General Computing Side is permitted.
Please disconnect it.
Jenne, Mike and I installed all of the post holders we could today including: REFL11, REFL33, REFL55, AS55, MCRef, POX11 and POP55. We did not install AS110, POY or REFL165 because there are interferences that will require moving stuff around. We also did not mount POP22 because it is a peely wally ThorLabs PD that will be replaced by a strong, straight and right thinking LIGO PD in the fullness of time. We did move it out of the way however which is no more than it deserves. Next step this afternoon Mike and I will install all of the telescopes and launching hardware. Then with the help of Steve we will begin routing the fibers. The splitter module will be here by next Monday, the laser by the following Friday and then we will light up the fibers.
Mike and I installed all of the telescopes and launching hardware for REFL11, REFL33, REFL55, AS55, MCRef, POX11 and POP55. On Monday afternoon Steve will work with us on the fiber routing. Steve is buying some protective covers for the fibers.
[ian, anchal, paco]
After our second attempt of locking PRFPMI tonight, we tried to resotre XARM and YARM locks to IR by clicking on IFO_CONFIGURE>Restore XARM (POX) and IFO_CONFIGURE>Restore YARM (POY) but the arms did not lock. The green lasers were locked to the arms at maximum power, so the relative alignments of each cavity was ok. We were also able to lock PRMI using IFO_CONFIGURE>Restore PRMI carrier.
This was very weird to us. We were pretty sure that the aligment is correct, so we decided to cehck the POX POY signal chain. There was essentially no signal coming at POX11 and there was a -100 offset on it. We could see some PDH signal on POY11 but not enough to catch the locks.
We tried running IFO_CONFIGURE>LSC OFFSETS to cancel out any dark current DC offsets. The changes made by the script are shown in attachment 1.
We went to check the tables and found no light visible on beam finder cards on POX11 or POY11. We found that ITMX was stuck on one of the coils. We unstuck it using the shaking method. The OPLEVs on ITMX after this could not be switched on as the OPLEV servo were railing to limits. But when we ran Restore XARM (POX) again, they started working fine. Something is done by this script that we are not aware of.
We're stopping here. We still can not lock any of the single arms.
Wed Jul 28 11:19:00 2021 Update:
Gautam found that the restoring of POX/POY failed to restore the whitening filter gains in POX11 / POY11. These are meant to be restored to 30 dB and 18 dB for POX11 and POY11 respectively but were set to 0 dB in detriment of any POX/POY triggering/locking. The reason these are lowered is to avoid saturating the speakers during lock acquisition. Yesterday, burt-restore didn't work because we restored the c1lscepics.snap but said gains are actually in c1lscaux.snap. After manually restoring the POX11 and POY11 whitening filter gains, gautam ran the LSCOffsets script. The XARM and YARM were able to quickly lock after we restored these settings.
The root of our issue may be that we didn't run the CARM & DARM watch script (which can be accessed from the ALS/Watch Scripts in medm). Gautam added a line on the Transition_IR_ALS.py script to run the watch script instead.