Oxide films and scanning probes J. Aarts , Kamerlingh Onnes Laboratory, Leiden University
Www.minigrail.nl Ultra-cryogenics for advanced resonant detectors (C2) G.Frossati Kamerlingh Onnes...
Transcript of Www.minigrail.nl Ultra-cryogenics for advanced resonant detectors (C2) G.Frossati Kamerlingh Onnes...
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Ultra-cryogenics for advanced resonant
detectors (C2)
G.Frossati
Kamerlingh Onnes LaboratoryLeiden, The Netherlands
Second ILIAS-GW Meeting October 24-25 2005Palma de Mallorca
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Sensitivity
Minimum detectable energy
Teff=T/Q +2TN
N B NE = k T =1 h with = 3KHz
-7NT 1.5×10 K
Need~0.05; Q~2x106: T~30 mK
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ROG SQUID
• Double SQUID made of a sensor d.c. SQUID, developed by the Institute of Photonic and Nanotechnologies of CNR, and a commercial Quantum Design d.c. SQUID as a preamplifier.
• Open input and in open loop configuration: 28hbar at 4.2 K and 5.5hbar at 0.9 K.
• Feedback network :37hbar in closed-loop open-input 4.2K.
• With a high-Q resonant input load :70hbar at 2 K.
www.minigrail.nlNext: 33 ton sphere ?Project together with the Roma
group to be submitted to INFN
hQL ≈4x10-24/√Hz
hQL≈4x10-23/√Hz
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ROG-Leiden-Geneva project: to be submitted to INFN
Use 4 GM cryocoolers for pre-cooling from 300K to 20K
Use 4 PT410 for cooling to 4K and for the
dilution refrigerator
GM600 (Cryomech) 1200W at 250KPT400 60W at 60K and 1W at 4.2k
Heat to remove ~70J/gm ~2.8x109JCool-down time ~2 weeks to 4k
SFERA33 +7 ton20000 N2
14000 L He !
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Dilution Refrigeration; Schematic view
CIRCULATIONSYSTEM
STILL
HEAT EXCHANGER
MIXING CHAMBER
STILLQ
HEAT ABSORPTION REGION
1k POT
HEAT FLOW
MCQ
STILLQ
TMC
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Pulsed tube dilutionrefrigerator
Joule Thompson heat exchanger replaces the 1K pot: No need for Helium bath
JT Heat exchanger
PTR
Mixing Chamber
50K
4K
600 mK
60 mK
10 mK