1 / 23

STREGA-C3 Cryogenic Seismic Isolation

STREGA-C3 Cryogenic Seismic Isolation. Roberto Passaquieti Dipartimento di Fisica “E. Fermi” Università di Pisa INFN sezione di Pisa ILIAS-GW Annual General Meeting , Palma de Mallorca 24-25 October 2005. STREGA-C3 Task: Description.

ramona-hopkins
Télécharger la présentation

STREGA-C3 Cryogenic Seismic Isolation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. STREGA-C3 Cryogenic Seismic Isolation Roberto Passaquieti Dipartimento di Fisica “E. Fermi” Università di Pisa INFN sezione di Pisa ILIAS-GW Annual General Meeting , Palma de Mallorca 24-25 October 2005

  2. STREGA-C3 Task: Description • The aim of C3 task is to realize a full anti-seismic cryogenic suspension system (cryostat+suspension) performing like a Virgo Superattenuator (SA). • Main Actions: • to design a cryo-compatible suspension prototype; • to install the prototype into a cryogenic environment; • to investigate and reduce the extra noise induced by the refrigerator. • To achieve such results it is foreseen the merging with the activities of C1 task; especially from the 4th year (1997) of the STREGA project (investigation on sensors and actuators; material properties; noise studies; simulation; etc.). ILIAS-GW Meeting, Palma, 25 October 2005

  3. C3 Task: Main Activities • Design and FEA of a Si test payload intended for a 1:1 scale measurement of the Si mirror Q down to ~ 5K with/without coating. • Investigations on high compliance thermal links at room temperature. • Assembly of a small suspension prototype (SAS) at room temperature. • Contribution to the realization of the EGO cryogenic test facility(CTF). • Design of a full scale cryogenic suspension prototype. Ta2O5 coatings,Yamamoto 2003 ILIAS-GW Meeting, Palma, 25 October 2005

  4. Task C3: 5 Years Implementation Plan 2004 2008 Budget: ~18.4 k€ ILIAS-GW Meeting, Palma, 25 October 2005

  5. Task C3: 13-30 Month Timetable ILIAS-GW Meeting, Palma, 25 October 2005

  6. Si Payload Prototype: Design • The designed test payload consists of a Si mirror (350mm diam., 100 mm thick) suspended to a Si marionette by two couples of monolithic silicon ribbons (300 x 30 x 0.8 mm3 each). • Si thermal expansion coefficientshows two zero crossings at 123K and 17K. • Displacement fluctuations of mirror driven by thermal expansionare strongly reduced at these low temperature values. • Si relatively high thermal conductivity has also positive effects in reducing mirror thermal lensing ILIAS-GW Meeting, Palma, 25 October 2005

  7. Si Payload: Design and FEA ILIAS-GW Meeting, Palma, 25 October 2005

  8. The EGO CTF is placed in a building (~ 450 m2) at the mid of the West arm of the Virgo interferometer. The EGO CTF cryostat has an inner 4K chamber able to contain a test payload with one anti-seismic filter stage. It will be suspended over a pit in the ground floor (13.8 x 5.45 x 1.95 m3). EGO Cryogenic Test Facility (CTF) W N CTF ILIAS-GW Meeting, Palma, 25 October 2005

  9. Status of Works at the EGO-CTF • The EGO-CTF infrastructure works are quite advanced: • the pit on the ground is completed; • the cryostat suspension structure is assembled; • the computer room and the laboratories are foreseen to be delivered by the mid of next November. ILIAS-GW Meeting, Palma, 25 October 2005

  10. Cryostat Support and Service Structures ILIAS-GW Meeting, Palma, 25 October 2005

  11. The EGO-CTF Cryostat • The designed cryostatconsists of an external vacuum-proof steel cylindrical vessel (2.6m height, 1.4 m diameter). • Inside the room temperature vessel there are two nested super-insulated Al chambers which are foreseen to reach their thermal equilibrium respectively at about 80K and 4K. • The 4K chamber will host the payload; it has an height of 2m and a diameter of 1.2m. 2m 1.2m ILIAS-GW Meeting, Palma, 25 October 2005

  12. The Cryo-Cooler PT410W: Power: 7.2kW @ 50Hz Stage1: 40W @ 25K stage2: 1W @ 4.2K Threshold:0W @ 2.8K Cooling: Liquid Acoust.N: 70dB @1m • The EGO-CTF cryo-cooling system is initially based on two pulse tube refrigerators (PTR). • The Pulse Tube Refrigerator essentially achieves criogenic temperature by expanding high pressure He gas to low pressure ( 2Hz). • Compression/expansion cycles are source of low frequency excess noise. • The INFN Pisa group (C3) will collaborate with the INFN Roma1 group (C1) that has already achieved experience on the PTR noise reduction. PT60W: Power: 3kW @ 50Hz Stage1: 60W @ 80K Cool.Thr.: 0W@ 30K Cooling: Liquid Acoust.N.:70dB @1m ILIAS-GW Meeting, Palma, 25 October 2005

  13. Status of the EGO-CTF Cryostat. • Cryomech Pt and compressors, are already purchased. • The EGO-CTF infrastructure are being completed • The last version of the cryostat design was ready from February 2005. • The cryostat has been already built. • Assembly and vacuum leak tests are being performed in the delivering workshop (Cryoanlagenbau) in Germany. ILIAS-GW Meeting, Palma, 25 October 2005

  14. The EGO-CTF Cryostat The AISI 316L external vessel The 2 AL, super-insulated, inner vessels ILIAS-GW Meeting, Palma, 25 October 2005

  15. The EGO-CTF Cryostat ILIAS-GW Meeting, Palma, 25 October 2005

  16. The EGO-CTF Cryostat ILIAS-GW Meeting, Palma, 25 October 2005

  17. Cryogenic SA Design: Components • SA functional blocks: • Filters • Blades • Magnets for anti-springs • Dampers • Sensors: LVDT, accelerometers • Actuators: coils+magnets • Cables • Motors • Adhesives • Need to be tested for cryogenics. ILIAS-GW Meeting, Palma, 25 October 2005

  18. Cryogenic SA Design: Materials • Suitable materials: • 300-series austenitic steels: 304, 304L, 316, 321, 304LN, 316LN • OFHC copper and deoxidized copper • Al alloys: 6061, 6063, 1100 • Titanium, Niobium • Invar • Kapton, mylar • quartz • Not recommended (undergo ductile to brittle transition): • martensitic steels • carbon steels • rubbers, plastics, Teflon • Maraging: 18Ni (200) series, already tested at room temperature down to 100K, exhibit ductile fracture ILIAS-GW Meeting, Palma, 25 October 2005

  19. Suspension Prototype Assembly • A small scale suspension prototype (SAS) is being assembled at the Pisa INFN laboratories. • It exhibits less cryogenic incompatible items (no magnets, no glue, no viton) and could be used at 4 K with minor modifications • Foreseen Activities: room temperature tests on • blades, • sensors, • actuators. ILIAS-GW Meeting, Palma, 25 October 2005

  20. Investigations for a Cryogenic SA • List of Investigations: • Selection of material for thermal links; measurement of the link stiffness down to cryogenic temperatures; measurement of the link thermal impedance. • Quality factor measurement of damping materials at low temperatures. • Definition of mechanical and thermal behavior of materials for filter components; test of a full assembled filter at cryogenic temperature. • Dimensioning of the electric cables, keeping into account the heat conduction and dissipation. • Test of the LVDT sensors and accelerometers at cryogenic temperatures. • Qualification of cryogenic motors and traslators. • Qualification of the pulse tubes from the point of view of their vibrations; design of a vibration attenuation system. ILIAS-GW Meeting, Palma, 25 October 2005

  21. 1x1x70 cm Aluminum l=60 cm Set of stripes Extra Stiffness Measurement of Soft Thermal Link Test Apparatus Prototype: set of 10+10 brass strips (0.3X0.01X0.00005 m3 each) ILIAS-GW Meeting, Palma, 25 October 2005

  22. Cryogenic SA Prototype: Preliminary Design ILIAS-GW Meeting, Palma, 25 October 2005

  23. Conclusions • The first year plan was fulfilled:a Si payload prototype was designed and its FEA was performed. • A small scale suspension prototype is being installed at the Pisa INF laboratory. • The EGO CTF is being delivered together with its cryostat. • The work done on the jellifish prototype need to be extended at low temperature. • The design of the cryogenic SA prototype and its cryostat is started. A preliminary design has been delivered (2nd year deliverable). • Interactions beetwen C1 and C3 tasks have been well clarified and organized. ILIAS-GW Meeting, Palma, 25 October 2005

More Related