[A proposal for ILIAS NEXT: Cryogenics versus vibration] [I3-FP7 call] Abstract The reduction of thermal noise in solids is a basic requirement in many kinds of detectors involving position or mechanical energy measurements. If cryogenics is used other favorable conditions are met as high quality factors or higher thermal conductivity such that the use of cryogenics appear a natural choice. The proposed activity is targeted to the leading feature of underground detectors. Vibration-free-cryostat (VFC [1,2,3,4]) activity is being proposed to be pursued pursued as JRA ILIAS in order to: • study the integration of VFC and cryogenic sensor development with running cryogenics R&D projects for gravitational wave detectors [5,6,7]; • study alternative configurations as vibration self- cancellation using double-pulse-tube systems [8]; • adapt vibration-free cryo-cooler experience to other astro- particle physics detectors requiring low temperature and quiet environment [9]; • design and develop new sensors dedicated to pulse-tube vibration reduction. 1 – Target
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[A proposal for ILIAS NEXT: Cryogenics versus vibration] [I3-FP7 call] Abstract The reduction of thermal noise in solids is a basic requirement in many.
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[A proposal for ILIAS NEXT: Cryogenics versus vibration][I3-FP7 call]
Abstract
The reduction of thermal noise in solids is a basic requirement in many kinds of detectors involving position or mechanical energy measurements. If cryogenics is used other favorable conditions are met as high quality factors or higher thermal conductivity such that the use of cryogenics appear a natural choice. The proposed activity is targeted to the leading feature of underground detectors.
Vibration-free-cryostat (VFC [1,2,3,4]) activity is being proposed to be pursued pursued as JRA ILIAS in order to: • study the integration of VFC and cryogenic sensor development with running cryogenics R&D projects for gravitational wave detectors [5,6,7]; • study alternative configurations as vibration self-cancellation using double-pulse-tube systems [8];• adapt vibration-free cryo-cooler experience to other astro-particle physics detectors requiring low temperature and quiet environment [9];• design and develop new sensors dedicated to pulse-tube vibration reduction.
1 – Target
2Paola Puppo - GWADW– May 14th 2009 – Ft Lauderdale
From S. Hild et all. http://arxiv.org/abs/0810.0604
2 – Motivation
Vibration compensation
Passive solution Active solution
Cold point displacement
sensor
Logic Unit
Force Actuation at room
temperature
A.D.C.
D.A.C.
Elastic suspension of the cold head
3 – PT cryostats
4 – VFC
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Vibration of the cold head reduced (@T=4K)Vibration of the cold head reduced (@T=4K)
[1] Tomaru T. et al., “Vibration analysis of cryocoolers”, Cryogenics, 44 309-317, 2004.[2] S. Caparrelli et al. , “Vibration-free cryostat for low-noise applications of a pulse tube cryocooler", Rev. of Sci. Inst. 77 9 095102, 2006.[3] E. Majorana et al., “Vibration Free Cryostat for cooling suspended mirrors”, Journal of Physics Conference Series 32 374–379, 2006.[4] F. Basti et Al., “Closed loop refrigeration systems and vibration control for a cryogenic gravitational-wave detector”, XIX AIV Congress, Senigallia 19 May, 2009 (in press).[5] P. Rapagnani and P. Puppo, “Cryogenic developments for future GW interferometers”, http://www.authorstream.com/Presentation/padapupps-75916-cryogenic-developments-future-gw-interferomet-gravitational-waves-interferometer-cryogenics-puppo-elba-science-technology-ppt-powerpoint/ GWDAW, Elba, Italy, 2008.[5] K. Kuroda “LCGT Project” http://gw.icrr.u-tokyo.ac.jp:8888/lcgt/ [7] K. Agatsuma, “Thermal noise limited underground interferometer CLIO”, Amaldi 8, 25 Giu. 2009 (in press).[8] Suzuki T. et al., “Pulse tube cryocooler with self-cancellation of cold stage”, http://arxiv.org/abs/physics/0611031v1, Cryo Prague 2006. [9] R. Ardito et al. “CUORE Collaboration: A cryogenic underground observatory for rare events” http://arxiv.org/abs/hep-ex/0501010 2005.
AUXILIARY NOT USED
Mirror cooling to get ET sensitivityMirror cooling to get ET sensitivity Test masses and suspensions thermal noise reduces at low temperature:Test masses and suspensions thermal noise reduces at low temperature:
Thermoelastic noise both of the mirror substrates and coatings decrease:Thermoelastic noise both of the mirror substrates and coatings decrease:
Thermal expansion rate a decreases at low temperature;Thermal expansion rate a decreases at low temperature;
Thermorefractive noise Thermorefractive noise
Losses of some materials decrease at low temperatureLosses of some materials decrease at low temperature
Tx 2
9
22 Tx
)(2 Tx
x 2 T 2
Paola Puppo - GWADW– May 14th 2009 – Ft Lauderdale
Silicon for substrates and suspensions: : • high thermal conductivity• very low thermal expansion
(zero below 17K)
The Pulse Tube CryogeneratorThe Pulse Tube Cryogenerator
Second stage
First stage
Compressor
High pressure linesLenght up to 20 m
High pressure flexible line
LCGT project
•It is a 3km Fabry-Perot MI with a power recycling scheme and equipped with a broadband RSE. The laser power is 150W•Main mirrors made of sapphire are cooled at 20K. A SPI impedes the refrigerator- vibration. •It is built underground at Kamioka. •Two independent interferometers are installed in one vacuum system.•The main target is the coalescence of BNS, which can be detected 1.2-27.8 events per year at confidence level of 95% for mass 1.4Msun and S/N=10.