NAOJ GW Elog Logbook 3.2
In order to state which part of the sample I was watching exactly, I used the sample boundaries as reference.
First I made a map with the DC signal in order to define the boundaries. I put it together in the same plot of the last absorption measurement (See Figure1.png). I could do that because I didn't remove the sample from the holder since the last measurement.
Then I took many pictures at the microscope and I put them together to make all mirror map. (See Figure2.jpg)
I overlap the two images making a matching of the boundaries. (See Figure3.jpg)
Finally I found the corresponding area. (See Figure4.jpg). The problem is that the pattern of dots at the microscope doesn't completely correspond to the absorption peaks pattern.
Members: Tatsumi, Fujii, Manuel.
JIG for gluing and necessary tools were delivered at NAOJ.
we wiped the tools one by one with ethanol before put inside the clean room. picture1.png
In order to carefully check the mechanical parts before gluing, we made a simulation of many of the gluing procedure steps:
- Unbox the JIG and clamp the basement on the optical table and attach the plastic move rod on the turn-table. picture2.png
- Set the alignment parts (the micrometer screws and the lenses) on the basement. picture3.png
- Through each lense we can see the magnified white mark to be aligned to the proper position of the mirror. picture4.png
- Remove the lenses and place the glueing parts for wire breakers: picture5.png and picture6.png
- Set the six posts to place the inner plate (3 shorter and 3 longer). And then, place the inner plate. picture7.png
(Unfortunately we found a little mistake on the hole position of one of the 3 shorter posts, we ask the company to fix it)
- Set the cilinder and close the JIG with the upper plate. picture8.png
- Open again the JIG and set the basement to stand up the JIG. picture9.png
We only have had 2D drawings of the mirror box's parts, and that prevents most of us from understanding the installation/hanging procedure of mirrors.
After the today's dry-run of the review (internal review) on the procedure, I've reconstructed the 3D data briefly from the 2D drawings, only which the manufacture company provided us (uploaded to the jgwdoc by Tatsumi-san).
If I didn't misunderstand the 2D drawings, the reconstructed 3D model shows a mechanical intereferance between one of the blue pillars and the mirror base (see the third figure attached).
And also, I think the base has a too narrow foot and should be widened!; the rail on the other side (the mirror-hanging jig) should be modified accrodingly.
In the last week I did some surface measurements with Zygos NewView8000 microscope on samples of Sapphire, SiO2-glass, and a GaAs-wafer from LMA.
Attached to this file are figures of the surface profile of each sample taken from the center and an area close to the edge of each sample.
The calculated surface roughnesses (rms) are as follows:
Sapphire-center: 1 nm
Sapphire-edge: 2nm
SiO2-center: 1nm
SiO2-edge: 1nm
GaAs-center: 2nm
GaAs-edge: 3nm
I made again a map of the same area of the LMA sample 15034. In the same conditions. I didn't unmount the sample from the holder, but I noticed that after one week it was dusty. So I cleaned it again with the first contact polymer. I show the picture of before and after cleaning. I show the comparison of the same measurement in the same conditions but after a week and a cleaning.
Fabian, Hirata, Shoda
We started the IM installation today.
Since we do not have a clamping tool for the cabling and some screws now, we are on the middle of the way.
I started to write an installation document:
https://docs.google.com/document/d/15Af4unTnrRd68tULCNv77kIi7h5c7p9246sUuCP1XCo/edit?usp=sharing
You can edit the document. Please read and write down if you find something missing.
I learned using COMSOL Multiphysics 5.1. I made a model of the sample in 2D with axisimmetric revolution around the pump beam axis. I built a thin rectangle for the absorbing coating (10 micron) and a thick rectangle for the substrate (3mm). The mesh is fine (1micron) near the heat source and in the coating, and coarse (0.5mm) far from the center (see the picture mesh.png). The heat source is a gaussian beam of size 70micron and power 1W. The absorption ratio is 12ppm. Chopper frequency is 430Hz but the waveform is a sine, because I'm going to compare this solution with the analitic solution which has a sine waveform instead of a square one. I attach the plot of the temperature of the point (r,z)=(0,0) as a function of time for 100 ms. And an animation of the temperature distribution. with the color scale in kelvin. I cannot upload the file and I don't understand why. It is a gif file and it's less than 10Mb. this is the link to my dropbox: https://www.dropbox.com/s/gd28tb1zc7gxdob/movie.gif?dl=0
Two viewport windows on the gate valve (GVs) between the MCF and IFI chambers are changed with new glasses with AR-coated as planned.
With this work, AOS has finished to change all the windows on the exsiting GVs in KAGRA to the AR-coated ones (10 pieces of windows in total).
This is a small milestone for AOS.
The details of the AR-coated windows are fonud in
http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2926
We brought the IM parts into the clean room.
The parts are on the green rack where the bottom filters sit below.
Two sets of the IM parts are brought inside except for the picomotors and bottom mass compensation parts.
And the some of the wire clamping do not have the same numbers on them because the clamping parts are not packed with same numbers.
We can assemble one set of IM with the parts inside, but please check the numbers on the clamping parts when you assemble the second IM.
Since the laser, which is currently used for the JASMINE scatterometer, features a far too high spreading of its width, I installed a lens to refocus the beam toward the sample.
This focussing had to be measured and compared with the theoretical development of the width (the beam should be Gaussian).
The result is satisfying as the theoretical curves mach the measured values within averaged errors of less than 5%.
It should be noted that the beam has two different width distrubutions, perpendicular to each other, which I denominate X and Y.
In the attached figure the development along a lenght-axis (the way of the laser) is shown with indicated positions of the laser, a mirror (this is the point zero, for practical reasons), and the used lens (f=200mm).
On the left side of the lens, the measured values of the laser widths as the laser produces them are shown (dots). They were fitted with the respective Gaussian beam development w(z) (lines).
On the right side of the lens, the measured values of the focussed laser widths are shown (again in dots), together with the theoretical development (lines), calculated out of the parameters as given by the fits of the left-side beams.
For the scatterometer itself, the sample is located approximately 27 - 28 cm away from the lens. The width should, thus, be in the range of 0.13 - 0.17 mm.
Installation movies on 28th July 2015 are linked from the following page.
http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/inoutoptics/2015/07/installation-of-a-laser-guidance-duct.html
http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/inoutoptics/2015/07/start-installation-of-a-laser-guidance-duct.html
Installation movies on 28th July 2015 are linked from the following page.
http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/inoutoptics/2015/07/installation-of-a-laser-guidance-duct.html
By Sakakibara-kun.
Locations of the iKAGRA beam dumps, so far around MCF and MCE, or rather ghost beams, are described here.
http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3900
Recently, Hirose-san gave me the measured surface maps of the PR3, PR2, SR3, and SR2 mirrors.
Since there were no PSD calculations yet, I did these with a scilab program that I have written for this purpose.
The results can be seen in the picture that is attached, together with the PSD of the beam splitter as comparison.
Obviously, all PSDs are not so different from each other which might be a good sign.
I did some measurements with a new device in the ATC for creating surface maps together with Ezaki-san and Flaminio-san.
We measured the roughnesses of surfaces of SiO2-glass, a sapphire plate and a GaAs-wafer.
The results are still in a raw-data format and I need some calculations first to give an overview.
I made maps of the LMA surface sample with
High resolution 70 micron of spacing (as the dimension of the pump beam).
Calibration factor used R=13 1/W.
Scan areas are 4mm x 3mm.
LMA sample 15034
nominal absorption = 0.65ppm
pump power = 6.3W
map mean = 5ppm (including very high spiky noise or dust or scratch)
most of area value = 0.85ppm
LMA sample 15032
nominal absorption = 4.5ppm
pump power = 3.36W
map mean = 17ppm (including very high spiky noise or dust or scratch)
most of area value = 5.4ppm
LMA sample 15033
nominal absorption = 12.8ppm
pump power = 1.18W
map mean = 20ppm (including very high spiky noise or dust or scratch)
most of area value = 14ppm
I made again a map of the same area of the LMA sample 15034. In the same conditions. I didn't unmount the sample from the holder, but I noticed that after one week it was dusty. So I cleaned it again with the first contact polymer. I show the picture of before and after cleaning. I show the comparison of the same measurement in the same conditions but after a week and a cleaning.
The 30 pieces of the coil bodies are "doubly" packed into clean polyethylene packs (made in a class-100 room, the provider said) in the ATC ISO-1 clean booth. Will be sent to KEK soon.
I found the solution to the heat equation in this article and I calculated numerically using Matlab.
I show the solution of the heat equation for an absorbing fused silica medium.
- oscillating pump gaussian beam size 70micron
- oscillation frequency 430Hz
- absorbing thickness 10micron
- absorbed power 0.1mW
- fused silica thermal parameters
- scale in Kelvin
I made two resolved maps of the entire surface of the reference sample (200micron scan step) where the surface is behind the pump (flipped sample). One scanning along X axis (left in the image) and one scanning along Y axis. It shows that there are little fluctuations and they are a bit larger perpendicular to the scan axis. This happens for both maps. This means there are some long time power fluctuations. Maybe it shows more clear in the second attached image where there is only a 2D map.
There is also a relevant difference between the center of the sample and near the edge, the maximum is near the center, and the difference depends on the map. Still to be understood.
