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KAGRA VIS (Mirror Assemble)
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DaisukeTatsumi - 12:48, Tuesday 09 June 2015 (94)Get code to link to this report
Flag thickness measurement

To design the ASSEMBLE JIG,

I made measurement of flag thickness as attached.

Non-image files attached to this report
KAGRA VIS (OSEM)
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TomotadaAkutsu, KokiOkutomi - 21:04, Monday 08 June 2015 (93)Get code to link to this report
OSEM preliminary test with a new test bench

OSEMs are preliminarily tested with a new OSEM test bench in a non-clean environment. The OSEM's LED and PD are operated by a test circuit (not an actual satellite box, but I and Okutomi-kun have just copied requred parts...)

The conbinations under test are:

  1. New LED holder with TSTS7100 and new PD holder
  2. Old LED holder with OP232 and new PD holder (NOTE!)
  3. Old LED holder with OP232 and old PD holder (NOTE)

NOTE: the "old" LED holder cannot hold a lens with the same manner as the ones used in TAMA300 SAS prototype now, as it is revealed that the adhesive of lens to the "lens holder" inside the LED holder cannot be usable in vacuum. I just make the lens holded somehow....... so the distance from the LED and the lens are changed. However, from the rough measurement of beam profile of light of the ones, I got impression that such a change of positions doesn't have effects on the performance... (preliminary)

What to be confirmed is the linear range. I'd like to compare the range with the one used in TAMA300 SAS prototype.

So far the linear range are almost all the same.

Obviously when the linear range is such, we don't need to use such a large area photodiode; it is too large and hard to fit new and old designed PD holder. A small aperture PD would have smaller capacitance, and that makes the cricuit easliy stabilized.

... and 4. Plot of data by Sekiguchi-kun for TAMA-OSEMs; the data's range differs from our setup so I just lineary scaled the vertical axis. It appears that the linear range would not change.

Images attached to this report
93_20150608135449_dcim1158.jpg 93_20150609134424_figure1.png
KAGRA AOS (General)
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SimonZeidler - 17:14, Monday 08 June 2015 (92)Get code to link to this report
Outgassing results of VB and MV

Regarding the Doughnut Baffle, the two promising candidates for a very good absorption/scattering coating have been tested for their ultra-high vacuum compatibility.

The results show that VB has better UHV capabilities then MV. Especially water seems to be highly abundant on the surface of MV.

Images attached to this report
92_20150608101356_1.jpg
KAGRA VIS (General)
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RyutaroTakahashi - 15:43, Monday 08 June 2015 (91)Get code to link to this report
Replacement of the breadboard in MCE
Member: N. Ohishi, H. Ishizaki, M. Barton, R. Takahashi

May 26
Checking condition of the clean booth at 1530-17:00 by Takahashi.
1) Turned on all (16) filters. 4 filters had been working before.
2) Hirose-san measured particles by the large counter. I measured particles by the small counter too. Number of particles was 5/L just after turnung on the filters. Humidity was 80.5%.
3) Hirose-san measured particles continuously during I walk around.

May 27
Replacement of the breadboard (1).
1) Cleaned the floor of the clean booth by the vacuum cleaner and the mope.
2) Opened the chamber.
3) Moved the optical bench into the clean boooth by the jib crane.
4) Extracted the suspension from the chamber and put it on the optical bench.
5) Extracted the breadboard. Up-down movement of the crane (chain block) is very slow.
6) Rapped the breadboard.

May 28
Replacement of the breadboard (2)
1) Cleaned the floor of the clean booth by the mope.
2) Cleaned inside the chamber by the vacuum cleaner, the wet wiper, and the dry cloth.
3) The SUS blocks were stacked after first disassembling. Since the guid rods are inside the MCF chamber, we don't use them. The crane can not move to ransverse direction. This is a problem.
4) Unpacked the renewaled breadboard and installed it into the chamber.
5) The breadboard extracted was enclosed by the wood box.
6) Rapped the suspension with decicant.
7) Closed the chamber.
KAGRA AOS (General)
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TomotadaAkutsu - 19:48, Friday 05 June 2015 (90)Get code to link to this report
Oplev Reciever

Now a prototype of the oplev receiver

http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3562

is well assembled. Note that the QPD circuit in the photograph below has a wrong connector, and should be modified soon.

Images attached to this report
90_20150605124759_dcim1153.jpg
KAGRA VIS (General)
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NaokoOhishi - 15:30, Thursday 04 June 2015 (89)Get code to link to this report
MCE Breadboard Replacement

27th-28th May,

Takahashi-san, Mark-san, Ishizaki-san, and Ohishi changed MCE breadboard.

Due to the unexpected stack cleaning work, surface level adjustment of the MCE board was postponed to 11th-12th Jun.

Inside the cleanbooth, humidity was  - 80% but cleanness was good -ISO class 4.

Optical bench was carried into the booth.

Attached pictures were taken by Koichiro (an Olympus camera equipped to NAOJ Kamioka branch).

Images attached to this report
89_20150604080444_p5270049.jpg 89_20150604080802_p5280081.jpg 89_20150604080820_p5280097.jpg 89_20150604080939_p5280082.jpg 89_20150604081033_p5280090.jpg 89_20150604082335_p5280074.jpg
KAGRA MIR (Absorption)
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DaisukeTatsumi - 11:22, Thursday 04 June 2015 (88)Get code to link to this report
Calibration with standard samples

[SURFACE SAMPLE]

Newport FRQ-ND02

Absorption   22.2%  at 1064 nm

pump power damage threshold 40mW

------------------------------------------------------------------------------------------------------------------------------------------------

Type UV Fused Silica Metallic ND Filter   ---> Inconel coated fused silica substrate

Optical Density                    0.2 at 633 nm 

Diameter                              1.0 in. (25.4 mm)

Thickness                            0.118 in. ( 3.0 mm)

Material                                UV grade fused silica

Surface Quality                    60-40 scratch-dig

Surface Flatness                  less than 1 lambda at 632.8 nm over the clear aperture

Wedge                                  less than 3 arc min

Wavelength Range              350 - 2000 nm

Diameter Tolerance             ±0.25 mm

Thickness Tolerance            ±0.25 mm

Clear Aperture                      central 80% of dimensions

Damage Threshold               30 W/cm2 CW, typical;

                                              not recommended for pulsed laser use

Angle of Incidence                0 degree

Transmission                        63.1 % at 632.8 nm

Optical Density Tolerance    ±7%

Chamfers                              0.25-0.76 mm face width

Chamfers Angle/Tolerance   45 ±15 degree

Cleaning                                Non-abrasive method, acetone or isopropyl alcohol on lens tissue recommended

[BULK SAMPLE]

Schott glass NG-12

Thickness                                      3.6 mm

Absorption rate                              116% /cm

Refractive index                             1.48 at 1014 nm

Pump power damage threshold     100 mW

--------------------------------------------------------------------------------------------------------

Absorption = 1.16 /cm * 0.36 cm = 0.418 = 41.8%

Images attached to this report
88_20150604035828_bulksample0150602.jpg 88_20150604035846_20150602surface.jpg
KAGRA VIS (Mirror Assemble)
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DaisukeTatsumi - 10:42, Wednesday 03 June 2015 (87)Get code to link to this report
Dummy flag for glueing test

Dummy flag and (prototype) flag base were delvered as attached file.

By using these parts I will try to adhere.

Non-image files attached to this report
KAGRA VIS (Mirror Assemble)
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DaisukeTatsumi - 13:10, Tuesday 02 June 2015 (86)Get code to link to this report
Hotplate for glueing

Hotplate                              AsOne      ND-1

Radiation thermometer       Fluke        62 MAX+

After the delivery, I made operation tests as an attached file.

Images attached to this report
86_20150602060735_rimg0004.jpg
KAGRA AOS (General)
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TomotadaAkutsu - 21:49, Friday 29 May 2015 (85)Get code to link to this report
Assy of Category A viewport windows with flange adapters (2pcs)
Images attached to this report
85_20150529144905_dcim1135.jpg
KAGRA MIR (Absorption)
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DaisukeTatsumi - 09:41, Thursday 28 May 2015 (84)Get code to link to this report
Pump beam course alignment

I made course alignment of the pump beam as shown in the attached file.

Then at final end of the laser I checked the laser power fluctuation.

Within a hour there is no obvious drift.

I wll make calibration test.

Non-image files attached to this report
KAGRA VIS (General)
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YoshinoriFujii - 22:44, Monday 25 May 2015 (83)Get code to link to this report
Installation of Finshig rod to KAGRA Bottom Filter
On May 21, I and Hirata-san assembled some Fishing rods and installed them to the KAGRA Bottom filters.
I summarized this below;
http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/vibrationisolation/2015/05/installation-of-finshig-rod-to-kagra-bottom-filter.html
KAGRA VIS (OSEM)
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TomotadaAkutsu - 19:17, Monday 25 May 2015 (82)Get code to link to this report
Flexi circuits

The current status of the flexi circuits for OSEMs are here:

http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3570

Mechanically it appears nice, but no holes for soldering... I'm waiting for the alternatives.

The next step would be measuring the outgassing rate at KEK.

KAGRA VIS (OSEM)
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TomotadaAkutsu - 19:20, Friday 22 May 2015 (81)Get code to link to this report
OSEM LED test

I've seen light proflies of LED candidates for OSEM: OP232 and TSTS7100, and found the latter is better in terms of the uniformity, which would be important parameter for OSEM.

Each LED is set in the LED holder of an OSEM, and I did the check above w/ and w/o the additional lens, which was said to help collimation of light; it looks helping situation somewhat.

When test benches are prepared, I can test them as OSEMs.

KAGRA MIR (Absorption)
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DaisukeTatsumi - 10:38, Thursday 21 May 2015 (79)Get code to link to this report
Laser Power Stability

Measurement of the laser power stability for optical absorption system.

I found the stability is less than 1% in a hour.

Non-image files attached to this report
KAGRA AOS (General)
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SimonZeidler - 18:11, Wednesday 20 May 2015 (78)Get code to link to this report
up-conversion with transfer functions

I have written a program to overcome the problems with the Flanagan-Thorne procedure for transfer functions having very strong resonances by using time series of seismic noise.

Still, the results are not as sufficient as without these resonances but better than the procedure from Flanagan and Thorne. I uploaded a graph.

Images attached to this report
78_20150522122026_transferfunctionprmsrmbs.jpg
KAGRA AOS (General)
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TomotadaAkutsu - 08:41, Tuesday 28 April 2015 (77)Get code to link to this report
Ray tracing through a uniaxial crystal

In order to consider the effects of birefringence or double refraction in a uniaxial crystal like sapphire or calcite, I personally wrote a document

http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3519

to follow the discussions in CQG 27 185015 (2010).

In short:

(1) The KAGRA ETM with 0.05-degree wedge at its AR side would not spilt optical beams due to birefringence or such splitting is ignorable even if the c-axis of the sapphire substrate is tilted in no more than 2 degrees to the HR surface; the effect is indeed small, as the difference between ordinary and extraordinary index of refractions of sapphire are small.

(2) I found the CQG paper mentioned above contained at least two typos in its eq. (7), as indicated in my document.

Be careful that I don't mention any effects from polarization mixture. A uniaxial crystal would be used as a wave plate, and that means, it will mix two electric-field vectors in a propagating light beam through the crystal if its c-axis is tilted. The phase modulation in the light could be converted to amplitude modulation and vise versa due to the effects...

KAGRA VIS (General)
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RyutaroTakahashi - 09:46, Friday 24 April 2015 (76)Get code to link to this report
Cleaning of the MCE clean booth (2)
Work in the KAGRA site.
Member: Takahashi, Ohishi, Ishizaki, Barton, Doi

[April 23 AM]
- Measured particles (4-10/L@1F, 29/L@2F).
- Removed lapping for the chamber.
- Wiped the floors by a mop.
- Wiped the chamber by wet cloth.
- Measured particles (2-4/L@1F, 11/L@2F)
KAGRA VIS (General)
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RyutaroTakahashi - 21:29, Wednesday 22 April 2015 (75)Get code to link to this report
Cleaning of the MCE clean booth
Work in the KAGRA site.
Member: Takahashi, Ohishi, Ishizaki, Barton

[April 21 AM]
- Checked the status around the MCE chamber.
- Found the alert for oxygen (19.0%).
- Went out of the tunnel.
- Calibrated the sensor.
- Reentered to the tunnel to measure the oxygen density (20.5-20.7%).

[April 21 PM]
- Cover the sheet over the clean booth to avoid drop water.
- Lapped the MCE chamber.

[April 22 AM]
- Wiped the roof of the 2nd floor in the clean booth.
- Wash the 2nd floor by city water using a water gun.
- Dried out the 2nd floor by wiping.

[April 22 PM]
- Wash the 1st floor by city water using the water gun.
- Wiped the roof of the 1st floor.
- Wash the 2nd floor by pure water using the other water gun.
- Wash the 1st floor by pure water using the water gun.
- Dried out the 2nd floor by wiping.
- Dried out the sheet by wiping.
- Measured particles (64900-77800/L@1F, 122200/L@2F)
- Turn on the fan of filters.
KAGRA AOS (General)
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SimonZeidler - 16:39, Friday 17 April 2015 (74)Get code to link to this report
Scattering measurements on VB and SB

Torii-san made another measurement on VB with his improved setup. So I calculated the BRDF according to his result.

I also did a first "real" measurement with the JASMINE scatterometer on a SB plate. I put the results in the attachment.

 

I was asked by the JASMINE people to tell them how to use the scatterometer. Maybe in the next time I will have to teach it to some of their students.

Images attached to this report
74_20150417093929_2.jpg 74_20150417094125_1.jpg