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12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting I o ILIAS - STREGA MEETING Fulvio Ricci Dipartimento di Fisica, Università di Roma La Sapienza & I.N.F.N.

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Presentation on theme: "12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting I o ILIAS - STREGA MEETING Fulvio Ricci Dipartimento di Fisica, Università di Roma La Sapienza & I.N.F.N."— Presentation transcript:

1 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting I o ILIAS - STREGA MEETING Fulvio Ricci Dipartimento di Fisica, Università di Roma La Sapienza & I.N.F.N. Sezione di Roma

2 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting The VIRGO-CRYO tasks final goal The final goal of VIRGO-cryo is the construction of full scale prototype of a suspended test mass at cryogenic temperatures The final goal is reached by merging the activity of task C1 and C3 during the last (4th) year of the project Task C1 : main activity ==>>the cryogenic payload ( lower part) -->> Roma La SAPIENZA Task C3 :main activity ==>>the cryogenic super-attenuator (upper part) -->> INFN PISA There are several items in common between C1 and C3 also during the first part of the project : for example the development of sensor and actuators at low temperature, the simulation software …..

3 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Acernese F., INFN & University Federico II, Napoli Babusci D., LNF INFN, Frascati Barone F., INFN Napoli & University of Salerno Barsuglia M., LAL-Orsay IN2P3/CNRS Bizouard M.A., LAL-Orsay IN2P3/CNRS Brisson V., LAL-Orsay IN2P3/CNRS Braccini S., INFN Pisa Bradaschia C., INFN Pisa Brocco L., INFN & University La Sapienza, Roma Calloni E., INFN & University Federico II, Napoli Cattuto C., INFN Perugia Cavalier F., LAL-Orsay IN2P3/CNRS Cella G, INFN & University of Pisa Cuoco E., INFN Firenze/Urbino Dattilo V., INFN Pisa Davier M., LAL-Orsay IN2P3/CNRS DeWaard A., Leiden University, Leiden, The Netherlands De Rosa R., INFN & University Federico II, Napoli Di Fiore L., INFN Napoli Di Virgilio A., INFN Pisa Dominici P., INFN Firenze/Urbino Eleuteri A., INFN & University Federico II, Napoli Ferrante I., INFN Pisa Fidecaro F., INFN Pisa Frasca S., INFN & University La Sapienza, Roma Frasconi F., INFN Pisa Frossati G., Leiden University, Leiden, The Netherlands Gammaitoni L., INFN Perugia Gennai A., INFN Pisa Giazotto A., INFN Pisa Giordano G., LNF INFN, Frascati Guidi G., INFN Firenze/Urbino Hello P., LAL-Orsay IN2P3/CNRS La Penna P., EGO Losurdo G., INFN Firenze/Urbino Majorana E., INFN Pisa Marchesoni F., INFN Perugia Martelli F., INFN Firenze/Urbino Mazzoni M., INFN Firenze/Urbino Milano L., INFN & University Federico II, Napoli Palomba C., INFN Roma Passaquieti R., INFN & University of Pisa Passuello D., INFN Pisa Perniola B., INFN Firenze/Urbino Punturo M., INFN Perugia Puppo P., INFN Roma Rapagnani P., INFN & University La Sapienza, Roma Ricci F., INFN & University La Sapienza, Roma Stanga R., INFN Firenze/Urbino Vetrano F., INFN Firenze/Urbino Vicere' A., INFN Firenze/Urbino Vocca H., INFN Perugia Contact persons: Fulvio Ricci ( fulvio.ricci@roma1.infn.it ) Stefano Braccini ( stefano.braccini@pi.infn.it ) fulvio.ricci@roma1.infn.it stefano.braccini@pi.infn.it

4 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting R&D on Cryogenics 1) Study of the refrigeration system - noise - refrigeration power 2) Suspension compatibility: thermal conduction and acoustic quality factor Q measurements 3) Sensors at low temperatures - accelerometers and position sensing devices - actuators Liquid helium Refrigerators hybrid system

5 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting ILIAS activity of the Gravitational Wave group of the University of Rome La Sapienza & INFN Roma 1 L. Brocco, S. Frasca, G. Martinelli, M Perciballi, C. Palomba, P. Puppo, P. Rapagnani, F. Ricci, E. Serrani The main R&D activities to achieve the realization of a full cryogenic suspension (task C1) are focused on a)Modification of a cryogenic facility hosting a new PTR refrigeration system for the mirror cooling b)Low temperature monitor of the additional noise generated by the refrigeration system c)Heat absorption measurements of the mirror substrates d)Development of sensors and actuators for the position control of the mirror that are compatible with the cryogenic environment e)Design and construction of a suspension last stage protype for a cryogenic environment

6 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting An alternative way to cool down without liquid helium: the new generation of Cryocoolers First stage Second stage Benefit - Ideal for applications that require efficient operation -No moving parts in cold head. -Minimal vibration, low acoustic noise. - High stiffness cold head allows mounting of heavy loads without extra structural support - High efficiency. 2 to 3 times higher efficiency than GM cryocoolers for loads load temperatures between 55 and 120 K. A "low frequency Pulse Tube Refrigerator (PTR) or "G-M style" pulse tube cryocooler, is a variant on a Gifford-McMahon (GM) cryocooler. PTR operate at low frequencies, typically <5 Hz. They use a conventional oil-flooded G-M compressor and a valve set near the cold head to convert the continuous flow of helium from the compressor to a low frequency pressure wave. The cold head itself has no moving parts. Because of their low frequency and high pressure ratio (up to 5:1), these cryocoolers are best suited to low temperature applications, and are competitive with GM cryocoolers at temperatures below about 65 K. Typical efficiencies are in the range of 4 to 9% of Carnot cycle.

7 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Vacuum chamber for hosting the payload Cold head of Pulse Tube Refrigerator PTR ready for cooling PTR Integration in the Rome cryogenic facility

8 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting The Rome cryogenic facility: acoustic insulation of the compressor station for PTR

9 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting First cooling test with PTR and a mirror sample: the thermal contact resistance

10 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting

11 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Elastic dissipation study at low temperature: the case of CaF 2

12 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Scheme –Ring down method Excitation –Hammer Transducer –PZT on suspension CaF2 sample 50 x 25 mm Multiple loop suspension of NbTi Experiment setup Setup side view

13 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Results on a small sample of CaF 2

14 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Work to be done - PT Refrigeration system : noise characterization to be completed in the low frequency region -In 8 weeks from now, we will start to set up the installation that includes the vibration compensation system -( we hope in the financial support of INFN Commissione II) - New mirror suspension to reduce the thermal resistance which will be coupled to an elastic holder at 4K - Q measurements on CaF 2 sample of 10 cm in diameter. -Parallel activity: study of an alternative design based on sub-cooled superfluid helium (at pressure of 1 bar)

15 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Vibration measurements performed on the CRYOMECH refrigerator with piezo-accelerometers at low temperature

16 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Vertical displacementHorizontal displacement Sensor noise Displacement noise of the cold stage

17 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Vibration free cryostat: modification of the Rome cryogenic facility Conceptual scheme

18 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting

19 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting

20 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting C3 TASK To build an anti-seismic mirror suspension with mechanical performance similar to VIRGO Superattenuators and equipped with items for the extraction of the heat absorbed by the mirror because of the impinging beam (< 1 W) C3 task

21 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Al / Cu ~1 m ~ 40 cm x Z Y 30 cm 1 cm Main Idea: Superattenuator mechanical filters coupled with high thermal conductivity stripes not affecting mechanical performances C3 task

22 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting 1x1x70 cm Aluminum l=60 cm Set of stripes Negligible Stiffness, Negligible effects on Q (measured) Enough thermal conductivity at 4 K (on paper) C3 task Preliminary tests of strips has been already performed

23 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting COLD FINGER Very Soft Joint Cryostat COLD FINGER Two possible strategies C3 task

24 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Possible Improvement (valid for both strategy) A Superattenuator of reduced size (Prototype assembled for tests at Pisa INFN laboratories) The new system exhibits less cryogenic incompatible items (no magnets, no glue, no viton,…..) and could be used at 4 K with minor modifications C3 task

25 12th May2004 Fulvio Ricci I o ILIAS-STREGA meeting Conclusions -We need to clarify the contribution of the various institution to the VIRGO cryo tasks -Specific meetings have to be organized -The experimental activity is already started at least in two labs -- Cooling strategy, excess noise and thermal resistance have been identified to be the preliminary topic of this R&D acivitys -


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