wide-angle-baffle

From a paper from Toukoku-san (2014), I have calculated the maximum magnetic dipole moment of solblack. It is 6*10^-5 Am^2.

From this, I have rerun the program and calculated the maximum influence of a magnetized wide-angle-baffle (non-suspended). The results can be seen in the graph attached to this report.

Backscatterometer

Torii-san has measured the DLC sample and discovered a small unsymmetry between "positive" and "negative" angles.
I will try to search for en explanation.

Regarding the ghost beam. Torii-san wants to create a conical shaped baffle (blackend by candle-soot) to avoid an influence of ghost beams and, at the same time, keeping the symmetry. I think that the ND filter is in a first glance OK and we should focus on the sample holder for solblack. After this, we can think of this baffle.

Enclosure for the compressor outside the ATC building was installed.

Today, the enclosure of the compressor for the cryostat at the ATC was installed. It is a very tall one indeed.

The actual installation of the cryostat will take place on 26 and 27 of March.

Geophone pre-amp and an adopter cable

Summary:

I soldered long pins to the geophone pre-amps to be used for the TAMA prototype test. I also made an adopter cable to convert the amphenol MIL-C-24682 10-6 connector to a D-SUB 9 so that we can connect the geophone output to the digital system.
I made three pre-amp circuits and one conversion cable. The next step is to connect the pre-amp to a geophone and connect it to the digital system through the converion cable to see if this chain of signal flow works or not.

Details:

Pre-amp circuit issue:

There are 6 pins sticking out on the pre-amp PCB. These were soldered during the in-air tests and the pins became unusable. These are ITT/Cannon 031-9074-002. I ordered 20 of them. When I got these, I found that the pins had a thick section at the end, which prevented them from inserted into the holes on the pre-amp PCB. After consulting with Okada-san of ATC, I decided to cut those unwanted section with lathe. It was a fun since it had been a long time since the last time I used lathe :-) After the machining, I soldered those pins into the pre-amp circuits.

Conversion cable:

The output from the air-tiight container (vacuum pod) of the geophone is Amphenol MIL-C-24682 10-6 (6-pin) (http://www.mouser.com/ds/2/18/26482_10-469475.pdf).
We need to make a conversion cable from Amphenol to D-SUB 9 as suggested by Mark's cabling document (http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3382).

Here is the construction of the cable I made today:

Amphenol   <- Flat twisted pair cable -> D-SUB

(A) +14V <- Brown -> D-SUB  pin 9
(B) SIG RET <- Red -> D-SUB pin 2
(C) POWER RTN <- Orange -> D-SUB pin 5
(D) +14 <- Yellow -> D-SUB  pin pin 4
(E) OUT P <- Green -> D-SUB pin 1
(F) OUT N <- Light Grey -> D-SUB pin 6

(E) and (F) are twisted.
 

Next step:

We should connect them all (including soldering of geohone output cables to the pre-amp PCB) and check if the signals are as expected.

Concerns:

Although I tried to keep the flange of the vacuum pod as clean as possible by putting on latex gloves, I think the flange and the cable, which are supposed to be put into vacuum, are not so clean. We need to clean them before installing. Also I wonder how the cables will be assembled for real KAGRA.

Resources  (compiled by Mark):

LDVT rack electronics, with a bit more on the Geophone (JGW-T1201255):
http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=1255

 

 

 

Current status of iKAGRA mirrors

Here iKAGRA mirrors are PR2, PR3, BS, ETM01 and ETM02.

ETM01 and ETM02 are silica Test Mass.

The attached file is checked by Hirose-san (KAGRA MIR group).

Sapphire Prism / Visual Check

[WORKERS] Ueda, Fabian, Tatsumi

We take photos of sapphire prism. These are not polished as shown.

 

More photos can be found at

JGW-T1503409

About Autodesk Vault

As most of you know, controlling versions of drawings are our headaches. Most of VIS members would know that Hirata-san prepared an Autodesk Vault server in one of our PC with kind helps of Obuchi-san in ATC. I installed a Vault client to the other PC and so far did some local tries and experiments on the Vault. As a result, I found that in order to start life with Vault,
(1) the first thing to do is to prepare an single PC in which one can open inventor files without skipping any parts, and
(2) the second is to prepare a reliable server in terms of protecting our information from broken; so far Yoshizumi-san kindly does weekly backups with her hands.

More things to do would be to change the current structures of directories for the drawings, but I guess it's too late; to do would cost higher than not to do.

About (1), more precisely speaking, I can say several other ways, but I just show the most rapid and unified way I believe. The important thing is to "match" the directory structures in the Vault server and the directory structure of your workspace in any time if you want to reflect your work results to the Vault system, but not all files --- imagine a mathematical entity "set". The important thing is to keep a hierarchic structure of directories. It seems a SVN-like concept is used in the background. It would be nice if you learn slightly about SVN system before starting to use the Vault. KAGRA has as well a SVN sever prepared by Aso-san.

PR2/PR3 OSEM issues

PR2/PR3 OSEM report 20150313
About reducing diameters of LED/PD holders' cylinder parts, I asked NAOJ/ATC ME shop to get a cost estimation from an outside company, and they got it, and was very cheap, so this work will be just ordered to the company.

Comment to Backscatterometer (Click here to view original report: 39)

Yes, Simon would be right. Please do the dump of ghost beams in that way.

Wide-Angle-Baffle

I made a simulation with my model calculating the strain on an OSEM magnet by assuming a slightly magnetized solblack coated Cylinder in 20cm distance vibrating with the Kamioka seismic noise. I call this "Model1". The result is attached to this report.

VB

I had a phone call with Steve from SNS about our maesurements on VB and the next steps.
Here are the main points:

1. They curently work on a new VB version which would be more stable against touching but this means also a higher reflectivity (first measurements at 2mum wavelengths show a 20 times higher value than the original VB) They are further try to work on this
2. For the original VB sample, he proposed a special covering of the parts with VB (namely the Doughnut-baffle) until the installation is done and a removal after the installation.
3. He will send me a cost estimation on the Doughnut-baffle by the end of next week
4. I also got information on the outgassing. It should be very low.
5. I will provide him our maximum budget for the Doughnut-baffle

Backscatterometer

There is maybe a problem with the ghost beams coming from the BS and hitting the Iris in front of the sample.
I am afraid that this will produce some additional scattering light which superpositions the backscatter-signal and disturb the measurements especially for wide angles.

Torii-san and I tried to set an obliqued ND filter in front of the Iris to remove the ghost beam hitting the surface of the Iris.
The first results seem to support my fears.
Estimated influence on photocurrent: 0.1 - 0.2 nA

How one can get the latest OSLogbook?

This is Prof. Hyung Won Lee at Inje University, Korea.
I want to install OSLogbook using for my lab.
my e-mail is hwlee@inje.ac.kr
Regards,

Comment to Archaiomelesidonophrunicherata (Click here to view original report: 11)

「意味はしらん。ただ綴りだけ知ってるんだ。」 --- 夏目漱石『吾輩は猫である』

Parity

I found the article by Araya-san in the latest issue of "Parity".

日本語のテスト

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

HTMLのヘッダーを書いてみたテスト

test from VIS

Elog test テスト

 

 

 

スタイル

Comment to Archaiomelesidonophrunicherata (Click here to view original report: 11)

After some research I find that Archaiomelesidonophrunicherata means "the good old honey-sweet songs from the Sidonian (play) of Phrynichus" - Aristophanes' "The Wasps" line 220.

Comment to テスト (Click here to view original report: 29)

Can we attach things?

テスト

Mark B: One more test. にほんごは、どうでしょう？