Cryopayload's Action Item List

A/I#

Identified on

Assigned to

Status/Output

Related to

Description

Due date

001

2013 Nov. 19

Sekiguchi, Hirose

Closed. Takanori and Osamu Miyakawa found the document about OSEM (it includes the schematic design of circuit) by themselves.

Control

Ask somebody in LIGO details of the circuit for OSEM.

2013 Nov. 26

002

2013 Nov. 19

R. Takahashi

Closed. Unfortunately, there is not 3 dimensional but only 2 dimensional design drawing.->#016

Overall design

3-D design drawing of Type-A is necessary (ASAP!). Ask to Gianni.

2013 Nov. 26

003

2013 Nov. 19

R. Takahashi

Closed. Ryutaro explained. However, further discussion is necessary.->(#011)

Vertical spring

About blade metal spring (vertical spring), the schedule and strategy and so on will be summarized by R. Takahashi, Ishizaki, Sekiguchi, and K. Yamamoto, and reported in the next meeting.

2013 Nov. 26

004

2013 Nov. 19

K. Yamamoto

Closed. (1)Eric is busy. Moreover, Eric does not use ANSYS or COMSOL. However, Yoichi (or his student) will calculate it using COMSOL (Kazuhiro wrote Yoichi on Microsoft Project).(2)No files remain in Ando lab.

Material

About the masses, including a recoil mass, intermediate mass, intermediate recoil mass, and platform, the evaluation of the eddy current damping is necessary. K. Yamamoto will ask (1) to Eric Hennes how much he can make his effort for this problem and whether he can provide files for Finite Element Analysis. (2) to Ando or Aso whether Nishi's file for eddy current damping still remains.

2013 Nov. 26

005

2013 Nov. 19

D. Chen

Closed. The Picomotor didn’t work at 77K. But that might be because of the cooling shock. So we will have quick cooling test.

Control

D. Chen will ask Uchiyama whether a picomotor can survive at cryogenic temperature.

2013 Nov. 26

006

2013 Nov. 19

D. Chen

Closed. He received the design drawing from Takanori.

Control

D. Chen looks for design drawing of a stage for Type-B, and some commercial stages.

2013 Nov. 26

007

2013 Nov. 19

K. Yamamoto

Closed. Kazuhiro rewrote it.

Control

The schedule for the control system should be considered again.

2013 Nov. 26

008

2013 Nov. 19

K. Yamamoto

Closed. Dan asked Ryutaro.

Control

About the procurement of the OSEMs, K. Yamamoto will consult R. Takahashi.

2013 Nov. 26

009

2013 Nov. 19

T. Suzuki

Urgent! In KEK, thrust bearing without grease was checked. Suzuki-san will ask the load and speed and so on. The cryogenic test is necessary. (Thrust bearing is about 50mm in diameter and 300kg load).

Control

Check whether the thrust bearing can work at the cryogenic temperature.

2013 Nov. 26

010

2013 Nov. 19

D. Chen (?)

Closed. (i)In order to fix LED and PD, circuit board is used. We must check circuit board is OK at low temperature. -> #019(ii)Dan shows 7m cable increases the noise. Long cable can generates oscillation at high frequency region. The length of cables for cryo payload is 20m in length. We must check how much the long (flat) cable generates noise. If it is a problem, satellite boxes in vacuum are necessary. (iii)Window of photo detector will be removed because nitrogen gas is in Photo Diode.

Control

About OSEM, (i)check about out gas; (ii)check noises by 10-m long line; (iii)check whether the window of photodiode be removed.

2013 Nov. 26

011

2013 Nov. 26

T. Sekiguchi

Closed. Takanori summarized and explained.Vibration via heat link (T. Sekiguchi)->#017

Vertical spring

For the basis of discussion, Takanori will summarize the vibration via heat link until this weekend. After that, he and Ryutaro circulate their ideas about vertical spring and we discuss.

2013 Dec. 1

012

2013 Nov. 26

K. Yamamoto

Urgent! He rewrote, but again, he must do so. First of all, strategy must be fixed.

Vertical spring

Kazuhiro rewrites schedule.

2013 Dec. 3

013

2013 Nov. 26

K. Yamamoto

Closed. He explained. Strategies for sapphire monolithic suspension 2(K. Yamamoto)He also revised schedule.

Sapphire monolithic suspension

Kazuhiro will summarize the details of schedule for monolithic sapphire suspension based on above discussion by the next meeting.

2013 Dec. 3

014

2013 Nov. 26

T. Suzuki and K. Yamamoto

Urgent!

Sapphire monolithic suspension

Suzuki-san and Kazuhiro will report the serious lack of human resources on the next year to SEO and EO.

2013 Dec. 3

015

2013 Nov. 26

R. Kumar

Urgent!

Sapphire monolithic suspension

Rahul investigates how much the lowest frequency of sapphire spring is. After that, we ask it is a problem for observation to Data Analysis group.

2013 Dec. 10

016

2013 Dec. 3

R. Takahashi, E. Hirose

Urgent!

Overall design

Type A 3 dimension drawing. Ryutaro gives Eiichi 2 dimensional design drawing and Eiichi makes drawings.

017

2013 Dec. 3

R. Takahashi, H. Ishizaki, T. Sekiguchi

Urgent!

Vertical spring

Design drawing for vertical spring in platform (Ishizaki and Takahashi). Takanori takes care of shape of blade spring. The load on GAS in Type B like is different from that of Ad LIGO like.

018

2013 Dec. 3

K. Yamamoto

Urgent!

Material

Kazuhiro summarize requirement of magnetization and so on before the meeting with Sumikin

2013 Dec. 17

019

2013 Dec. 3

R. Takahashi

Urgent!

Control

Ryutaro will consult Saito-san on the outgas of circuit board for OSEM.

020

2013 Dec. 3

K. Yamamoto

Urgent!

Sapphire monolithic suspension

Kazuhiro summarize the length of sapphire fiber. He must take bending point into account.

17 Dec 2013

021

2013 Dec. 3

K. Yamamoto

Urgent!

Sapphire monolithic suspension

Kazuhiro write the report about backup plan.

17 Dec 2013

022

2013 Dec. 3

D. Chen

Urgent!

Sapphire monolithic suspension

He considers structure in the intermediate mass (sapphire blades, stepping motor, stages). Later we discuss.

17 Dec 2013

023

2013 Dec. 10

Urgent!

Overall design

Baffle design : Mirror can observe the frame of hole of radiation shield for laser beam. It is an issue of scattered light. We also consider how to reduce the size of baffle.

024

2013 Dec. 10

Y. Aso, E. Hirose

Urgent!

Sapphire monolithic suspension

Yoichi Aso and Eiichi Hirose prepare the plan of optical contact and screw, respectively.

24 Dec 2013

025

2013 Dec. 10

E. Hirose

Urgent!

Sapphire monolithic suspension

Eiichi prepares document describing planned test and contributions.

24 Dec 2013

026

2013 Dec. 10

D. Chen

Urgent!

Sapphire monolithic suspension

Dan will ask Ryutaro what is pro and con of large intermediate mass.

17 Dec 2013

027

2013 Dec. 10

T. Suzuki

Urgent!

Sapphire monolithic suspension

Suzuki-san has data of friction between sapphire and metal and he will circulate later.

17 Dec 2013

028

2013 Dec. 10

Y. Aso

Urgent!

Vertical spring

Yoichi checks vibration transfer function of heat links with extra pendulums and whether weight of mass of these pendulums can be on the order of kg using ANSYS or COMSOL.

029

2013 Dec. 10

T. Suzuki, S. Koike, C. Tokoku

Urgent!

Vertical spring

Suzuki-san asks Koike-san to provide design drawing of shield. Tokoku-san learns how to handle it in CAD.