Cryogenic System Integration Meeting 2014 FY

2014.04.22

• Management & Schedule (Suzuki)

• Installation (Tomaru, Suzuki)
• Mirror Cryostat (Sakakibara, Kimura)
• Duct Shield (Sakakibara, Kimura)

  • Duct Shield Test(Y. Sakakibara)

• Cryocoolers (Tomaru, Suzuki)
• Room temperature SAS (Sekiguchi, Takahashi)
• Cryo-Payload
  • Heat link (Sakakibara)
  • Design (PF, IM, IMR) (Hirose, Sekiguchi, Rahul, Takahashi)
  • 1) Finally Bill Hollander at HPD contacted me proposing a meeting in a couple of days.
  • 2) Hirose visited Shinkosha to discuss ear configuration. I proposed a strength test with test pieces which is similar to what we have done at KEK. It is essentially a pulling test with R125 surfaces done by them. Yusuke made drawings and asked a quotation already.
  • 3) Rahul is preparing models to predict performance of both cradle and ear configuration.
  • 4) Vertical spring in PF: Takanori designed a prototype and we are asking Eric to review it and refine it.
  • 5) Ryutaro is visiting Eric to discuss this.
  • 6) Vertical spring test will be taken over by Kazuhiro?
  • 7) Hirose will be absent due to attend a seminar in Tokyo.
  • Fabrication (PF, IM, IMR) (Tomaru):
  • Moving Mass (Chen, Tomaru):
  • Recoil mass
  • Sapphire Mirror (Hirose)
  • Sapphire Mirror Suspension (Chen, Sascha, Yamamoto)
  • Test

  • Status of R&D (K. Yamamoto)

• Minutes(K. Yamamoto)

2014.04.15

• Management & Schedule (Suzuki)

  • First kick-off meeting with MESCO for cryostat installation at Apr. 10 at Kamioka. Slides.

• Installation (Tomaru, Suzuki)

  • Optical windows (T.Tomaru)

• Mirror Cryostat (Sakakibara, Kimura)

  • CAD_Top_shieldpipe (Koike)

    • Original CAD sever: http://wiki.kek.jp/display/gw/Cryogenics+CAD

• Duct Shield (Sakakibara, Kimura)
• Cryocoolers (Tomaru, Suzuki)
• Room temperature SAS (Sekiguchi, Takahashi)
• Cryo-Payload
  • Heat link (Sakakibara)
  • Design (PF, IM, IMR) (Hirose, Sekiguchi, Rahul, Takahashi)
    • 1) Planning to have a review meeting of vertical spring (date is not determined yet)
    • 2) A quote came for a prototype ear from Shinkosha
    • 3) No answer from HPD yet
    • 4) Prototype test plan (cradle) was discussed yesterday (Yusuke uploaded minutes on archive). We need to prepare things before sapphire parts arrive. What we want to make clear are, verification of hanging, bounce mode frequency, mirror temperature with/without thermal input (~1W), fiver quality factor (comparison with independent measurement), to check dynamics of the mirror when pushing it with actuators and so on.
    • 5) Trying to build a system model to study thermal noise.
  • Fabrication (PF, IM, IMR) (Tomaru):
  • Moving Mass (Chen, Tomaru):
  • Recoil mass
  • Sapphire Mirror (Hirose)
  • Sapphire Mirror Suspension (Chen, Sascha, Yamamoto)
    • Quotation for round polish was asked and we wait reply. We have quotation of flat cut.
  • Test

  • Status of R&D (K. Yamamoto)

    • In the last cryo payload meeting, we picked up R&D items behind schedule Minutes(K. Yamamoto).

    • What is the first priority ? What kinds of information are necessary for design ?
    • Vertical metal spring : Temperature dependence of Young's modulus and resonant frequency. According to schedule, by the end of March, one blade spring cryogenic test and triple blades procurement are finished.But actually, not yet. Triple blades must be prepared soon.
    • Heat links : Measurement of thermal resistance at end of heat link. The result affect the number of heat links. Layout (geometry must be symmetric).
    • Control : Test for stepping motor and thrust bearing. Active damping system. Coil magnet actuator. Sizes of these systems are necessary for design (how accurate ?).
• Baffle and Auxiliary Optics Subsystem (Akutsu)

• Minutes(K. Yamamoto)

2014.04.07

• Management & Schedule (Suzuki)

  • First kick-off meeting with MESCO for cryostat installation at Apr. 10 at Kamioka. We will discuss about installation schedule of the end cryostats.
• Installation (Tomaru, Suzuki)

  • Cryo-installation (T.Tomaru)

• Mirror Cryostat (Sakakibara, Kimura)
• Duct Shield (Sakakibara, Kimura)
  • We will release a specification document of duct shield in this week. Three duct shield will be fabricated in this FY.
• Cryocoolers (Tomaru, Suzuki)
  • We will release a specification document of first three low-vibration cryocoolers for the duct shields in this week. Now we discuss about the cost of one-stage pulse-tube cryocoolers with the cryocooler company since they are under considering the price down of the PTC. If the price is acceptable, we will not chose solvey cryocoolers but chose PTCs.
• Room temperature SAS (Sekiguchi, Takahashi)
• Cryo-Payload
  • Heat link (Sakakibara)
  • Design (PF, IM, IMR) (Hirose, Sekiguchi, Rahul, Takahashi)
    • A remote meeting was held on March 28th.
    • HPD gave us a quote for moving mass for PF and IM, and torsion adjustment
    • We gave them links to room-temperature VIS. They are looking into them to figure out an estimate for preparing necessary drawings for the modification.
    • We ordered sapphire parts for the cradle configuration to Shinkosha.
    • We would like to propose for an ear configuration (will explain it today). I asked a quotation about the ear to Shinkosha.
    • Rahul is preparing models for ANSYS.
    • Takanori is looking into control issues (sensors and actuators)
    • Takahashi-san started a cryogenic bade test
    • Need to prepare a solid test plan for the system (installation, strength, heat conductivity, controllability, and so on)

  • Fabrication (PF, IM, IMR) (Tomaru): Suzuki-san and I had meeting with Mitaka-koki Co. for Cryo-pendulum fabrication. They have interesting in our cryo-payload fabrication and accepted the style that they fabricate the payload with R&D with us.

  • Moving Mass (Chen, Tomaru): I got stepping motor which can work at cryogenic temperature but it didn't have driver. Can we get it?
  • Recoil mass
  • Sapphire Mirror (Hirose)
    • Contracts for FY2014 are in preparation.
  • Sapphire Mirror Suspension (Chen, Sascha, Yamamoto) Yesterday, we discussed the strategy. Fiber nail head is hooked by blade spring which is similar to that from Shinkosha. For comparison, we must collect quotations for flat cut or round polish.
  • Test
• Baffle and Auxiliary Optics Subsystem (Akutsu)
  • Location of a wide-angle baffle should be discussed.
  • Interface parts between a wide-angle baffle and a cryo-duct shield should be discussed.
  • Non-arm side, i.e. btwn BS-ITM, we need to consider the way to control stray light; as a reference, there are no baffles are installed closed to the ITM side in LIGO so far, but around BS, there is a baffle.
  • The recoil mass of the ITMs/ETMs should have also a function of baffle. Let's consider about it.

• Minutes(K. Yamamoto)