- Fixed the (ts) model, got strange results that indicate that the antisymmetric heating mode is much more prominent than previously thought
- Managed to get COMSOL data through matlab and into SIS
- Realized that the strange deformations that we were seeing only occur on the face nearest the ring heater, and not on the face we are worried about (the HR face)
- Read papers by Morrison et al. and Kogelnik to get a better understanding of the mathematics and operations of the optical cavity modeled in SIS
- Read some of the SIS manual to better understand the program and the physics that it was using (COMSOL licenses were full)
- Plugged the output of the model with uniform heating into SIS using both modification of the radius of curvature, and direct importation of deflection data
- Generated a graph for asymmetric heating and did the same
- Aligned axes in model to better match with the axes in MATLAB and SIS so that the extrema in deflections lie along x and y (not yet implemented in the data below)
- Verified that the SIS output does match satisfy the equations for Gaussian beam propagation
- Investigated how changing the amount of data points going into SIS changed the output, as well as how changes in the astigmatic heating effect the output
+ The results are very dependent on number of data points (similar order changes to changing the heating)
+ Holding the number of data points the same, more assymetric heating tends to lead to more power in the H(2,0) mode, and less in the H(0,2)
- Did more modeling for different levels of heating and different mesh densities for the SIS input.
- Lots of orientation stuff
- Started on progress report.
- Attended a lot of meetings (Safety, LIGO Orientation)
- Finished draft of week 3 report (images attached)
- Paper edits and more data generation for the paper (lower resolution grid data)
- Attended a talk on LIGO
Plan for building the model
- Find the fields that would be incident on the beam splitter from each arm (This is done already)
- Propagate these through until they get to the OMC using the TELESCOPE function in SIS
- Combine the fields incident on the OMC in MATLAB and minimize the power to get the input field for the OMC (Most of this is done, just waiting to figure out what kind of format we need to use it as an SIS input)
- Model the OMC as an FP cavity in SIS
+ Need to think about how to align the cavity in a sensible way in SIS (need to find out more about how they actually do it)
- Pick off the fields from both ends of the OMC-FP cavity for analysis
- Add thermal effects to one of the arms and see how that changes the fields, specifically how the signal to noise ratio changes
- Finished the MatLab code that both combines two fields and simulates the adjustment of the beamsplitter to minimize the power out (with a small offset).
- Added the signal recycling telescope to the SIS code that generates the fields
To Do: Make the OMC cavity in SIS
- Had a meeting to talk about the basics of LIGO (esp. TCS) and discuss the project
- Created COMSOL model for the test mass with incident Gaussian beam.
- Added a ring heater to the previous file
- Set up SVN for the COMSOL repository
- Got access to and started working with SIS on Rigel1
- Fixed SVN issues
- Refined COMSOL model parameters and worked on a better way to implement the heating ring to get the astigmatic heating pattern.
- Created a COMSOL model with thermal deformations
- Added non-symmetrical heating to cause astigmatism
- Worked on a method to compute the optical path length changes in COMSOL
- Tried to fix COMSOL error using the (ts) module, ended up emailing support as the issue is new in 4.3
- Managed to get a symmetric geometric distortion by fixing the x and y movements of the mirror to be zero (need to look for a better way to do this as this may be unphysical)
- Worked on getting the COMSOL data into SIS, need to look through the SIS specs to find out how we should be doing this (current method isn't working well)
Made a COMSOL model that can include CO2 laser heating, self heating, and ring heating
Figured out how to run SIS out of a script and set up commands to run the two SIS stages of the model
The 50W Access Laser is now in the lab. We need to wire up the interlock to the laser, plumb the chiller lines to the power supply and to the laser head and also wire up all the electrical and electronics cables. Additionally, we will need to plumb the flow meter and attach a circuit to it that triggers the interlock if the flow falls too low.
I added the following line to ~/.bashrc
Restored work done in http://nodus.ligo.caltech.edu:8080/TCS_Lab/201
Acromag IOC process was removed from PSL lab acromag1 computer a few months ago. Aidan needs them again but it would be better if it were run from TCS lab computers.
An instance of the modbus IOC is now running on tcs-ws within a docker container. Docker is named tcslabioc. Configuration files are located in ~/modbus. Instructions on how to use the docker are located in ATF:2249. To install docker see google.
To set up the specific instance in the TCS lab run
>sudo docker run -dt --name tcslabioc -v /home/controls/modbus/test_acromag.cmd:/home/modbus/IOCStart.cmd -v /home/controls/modbus:/home/modbus -p 5064:5064 -p 5065:5065 -p 5064:5064/udp -p 5065:5065/udp andrewwade/modbusepicsdocker
Then whenever you want to stop, run:
> sudo docker stop tcslabioc
or to restart run
>sudo docker restart tcslabioc.
So if you update the .cmd or .db files just run the restart command above and the channels should automatically update when it reboots. For other cleanup and control commands see docker documentation. It can also be configured to keep alive on system reboot.
The cmd and db files are included below in the attachments for reference.
I added some 0.004" thick indium sheet to the copper heat spreaders and and the heat sinks on the side of the HWS to try and improve the thermal contact. Once installed the steady state temperature of the sensor was the same as before. It's possible that the surface of the copper is even more uneven than 0.004".
contents of tcs_daq: /target/TCS_westbridge.db
I updated the .bashrc file in controls@hartmann to include aliases for the ezca EPICS commands and a few others. Details shown below:
Also added launchers to the top panel for MATLAB, sitemap, dataviewer and StripTool. The icons for the launchers are located in:
Changes to .bashrc
alias StripTool = "/cvs/opt/apps/Linux/medm/bin/StripTool"
alias sitemap='medm -x /cvs/cds/caltech/medm/c2/atf/C2ATF_MASTER.adl'
# EPICS aliases
I've added the following channels to the HWS softIoc in /cvs/cds/caltech/target/softIoc/HWS.db
EPICS and DAQ restart procedure
ps -e | grep softIoc"
[controls@hartmann softIoc]$ /cvs/opt/epics-3.14.10-RC2-i386/base/bin/linux-x86/softIoc -S HWS.cmd &
[controls@hartmann softIoc]$ dbLoadRecords "HWS.db"
## EPICS R3.14.10- $R3-14-10-RC2$ $2008/10/10 15:01:51$
## EPICS Base built Oct 28 2009
iocRun: All initialization complete
3. Edit the /cvs/cds/caltech/chans/daq/C4TCS.ini file and kill the daqd process on fb1. It should restart automatically.
Under edit ...
I added the names of the network machines to the /etc/hosts file on princess_sparkle, tcs_daq and tcs_ws.
I also added the /cvs drive on fb1 to the /etc/fstab file on princess_sparkle so that can be accessed from those machines.
Added the following to the frame builder in /cvs/cds/caltech/chans/daq/C4HWS.ini and restarted daqd as per instructions in http://nodus.ligo.caltech.edu:8080/TCS_Lab/29
I'm in the process of aligning the cross-sampling experiment for the HWS. I've put the 1" PBS cube into the beam from the fiber-coupled SLED and found that the split between s- and p-polarizations is not 50-50. In fact, it looks more like 80% reflected and 20% transmitted. This will, probably, be due to the polarization-maintaining patch-cord that connects to the SLED. I'll try switching it out with a non-PM maintaining fiber.
I added the four Athena DAC channels to the second BNC patch panel in the rack. At the moment there are only two EPICS channels in the database:
To the best of my ability, calculated the magnification of the plane of the test optic relative to the HWS (2.3) and input this value.
Increased the temperature slightly and saved data points of defocus to txt files when temperature leveled out. This was a slow process, as it takes a while for things to level out. I only got up to about 28.5C, and will need to continue this process.
I also plotted the best-fit defocus for each temperature from COMSOL (Temperature vs. Defocus), and looking at values from HWS it seems that we're off by a normalization factor of approx. 4.
I labelled and strung 8 of the 16 custom 40' BNC cables from L-Com between the HWS table and the BNC feed-through on the rack. Each cable is labelled HWS TABLE CHxx where 01<= xx <= 08. I'm going to leave the other 8 until we have room in the BNC feedthrough on the rack.
I've added a softIoc to TCS-WS to capture the beam size from the MAKO camera. The IOC is run using ...
controls@tcs-ws:~$ softIoc -S EPICS_IOC/iocBoot/iocfirst/st.cmd &
The st.cmd contains the following text:
controls@tcs-ws:~$ more EPICS_IOC/iocBoot/iocfirst/st.cmd
The db file is:
controls@tcs-ws:~$ more EPICS_IOC/db/beamSize.db
These are also being written to frames on FB4.
See attached photo for how data is written to frames ...
I have borrowed TCS's label maker in CTN for few days. If you need it, you can take it from the top of blue cabinets.
I lent your fancy Newport TrueRMS Supermeter with the thermocouple plugs on the top to the SURF student Jordon. He has it in the cryo lab or the EE workshop with one of the PSL lab temperature probes.
Borrowed thorlabs power meter on 21 Sep 2017. It is on the south table of the ATF lab.
The custom pieces of the Bosch framing have arrived. Transportation is currently moving them downstairs to the lab. The packing list is attached.
I bought this laser diode from Thorlabs today to try the current modulation trick Phil and I discussed last Friday.
It arrived on Friday.
I measured the reflectivity of a possible HWS replacement mirror at 532nm. Thorlabs BB2-EO3
Incident power = 1.28mW
Reflected power = 0.73mW
R = 56% at 45 degrees AOI.
This is an amended version of simple_take.c.
The files below are all in the directory /opt/EDTpdv/hartmann/src
The carpentry shop removed wet plaster sections from the wall following the flood (process was gentle scraping of wet plaster flakes, supervised by me). The wet section of wall needs a few days to dry and then they will plaster and paint it.
Here's a copy of an email I distributed today that describes the centroid and simulation code I wrote.
I've written some code that generates an image of Gaussian spots and provides you with the coordinates of the centers used to generate those spots. There is the facility to turn on i) photo-electron shot noise, ii) random displacement of the nominal positions of the centers from a regular array and iii) 12-bit digitization to more accurately model the output from a CCD.
I've included an example routine that calls this function and then centroids those spots using a variant of your centroiding algorithm.
You should be able to use this to generate reliable simulated data to test versions of your centroiding algorithm.
1. test_spot_generation_and_centroiding.m - the example routine. Run this first
2. generate_simulated_spots.m - the function to generate the simulated spots in an image and as a set of positions
3. centroid_image.m - the function to centroid an image
I changed the ownership of /opt/EDTpdv to controls with the command:
controls@princess_sparkle:/opt/EDTpdv$ sudo chown controls EDTpdv/
I cleaned up the HWS table in preparation for replacement with the 4x10 table. We still need to move the cabinet and get the enclosure out of the way.
We managed to successfully apply frame rate control via external trigger from a pulse generator.
We supplied 5V pulse train when connected to the optocoupler load, and connected to pins 1 and 2 of external trigger (on the frame grabber board) for using camera 0 (which is the case for us).
Then made the following changes to the config file dalsa_1m60.cfg;
MODE_CNTL_NORM: A0 (previously this value would have been 00)
user_timeout: 0 (this line should be added)
Then I saved the new config file as dalsa_1m60_et.cfg
Next, I loaded the new config using initcam command, then set the exposure mode to be 3. This can be done either using serial_cmd directly or using HS_Camera method set_exposure_mode.
In exposure mode 3, the exposure time is set by the time separation between the falling edges of the pulses, and the camera sets the expousure time to be the maximum value possible (as specified in the camera manual).
Then I took 10 images using take command, and verified that the frame rate is equal to the frequency of the pulse. We tested 1 Hz and 2 Hz pulse trains, and the frame grabber recoded 1 frames per sec and 2 frames per sec respectively.
We could not yet test the frequency values < 1 Hz as pulse generator we used could not go under 1 Hz.
We used another pulse generator to test pulse frequencies under 1 Hz, and verified that external trigger mode still works.
These settings work to get a computer onto the TCS/ATF network.
Spelt out in a searchable fashion:
iface <portname> inet static
dns-nameservers 10.0.1.1 188.8.131.52 184.108.40.206
I've set up the HWS with the probe beam sampling two optics in a Michelson configuration (source = SLED, beamsplitter = PBS cube). The return beams from the Michelson interferometer are incident on the HWS. I misaligned the reflected beam from the transmitted beam to create two Hartmann patterns, as shown below.
The next step is to show that the centroiding is a linear superposition of these two wavefronts.