DRD6 Liquid xenon detector technology First Xenon Liquefaction

D_R&D_6 Liquid xenon detector technology First Xenon Liquefaction at Nantes by using Pulse Tube Cryocooler Tom Haruyama (KEK) Eric Morteau, Patrick Le Ray, Cyril Grignon Noel Servagent, Jean-Pierre Cussonneau Dominique Thers (Nantes) Workshop FJPPL’ 07, 9 -12 May 2007, KEK, Japan

…following Dominique’s talk…. 1. LXe PET cryogenic system at Nantes 2. Pulse Tube Cryocooler Development at KEK 3. First xenon liquefaction at Nantes 4. Application to other Liquid Xenon Experiments 5. Summary and plan for this year

Liquid xenon - any specialties in cryogenic?

Physical Property of Xe Property T(K): temperature at 0. 1 MPa (kg/m 3): density at 0. 1 MPa lv(k. J/kg): latent heat (liquid)/mass Lv(k. J/L): latent heat (liquid)/volume ls(k. J/kg): latent heat (solid)/mass Ls(k. J/L): latent heat (solid)/volume Triple point LXe (saturated) LN 2 (saturated) 164. 78 2947 77. 24 807 95. 8 282 1. 2 3. 5 199. 0 161 28. 4 22. 9 161. 36 K 0. 0815 MPa 63. 148 K 0. 0125 MPa …How to cool ?

Cooling method – Mechanical refrigerator- Specially, Pulse Tube Cryocooler: Advantages: -Just switch on! For… -Precise temperature and pressure control, -LN 2 -Free operation -Quiet, maintenance free for years’ operation Cooling power requirement: -up to ~200 W @165 -170 K Developed at KEK

KEK-developed High-Power Pulse tube Cryocooler -Cooling power achieved ~70 W @165 K -Technology Transferred for upgrading to 200 W KEK-Iwatani PC 150

First Xenon liquefaction at Nantes, March. April 2007

General set-up

Xenon gas main tank with LN 2 vessel Gas purification panel

Pulse tube cryocooler Experimental chamber with a pulse tube cryocooler Helium compressor

Temperature profile during precooling

Pressure profile during precooling

Liquid xenon level profile 6 L Liquefaction Steady state 1 day

Liquid xenon temperature and pressure profile (steady state) Pressure profile Temperature profile

Now, this PT cryocooler is ready for extended scientific experiments, MEG, XENON 10, …

Final MEG LXe Calorimeter • 800 liter LXe detector with 850 PMTs • Total heat load: 130 W at 165 K

XENON 10 Experiment for Dark Matter search in Gran Sasso underground

Summar y First xenon liquefaction at Nantes by Pulse Tube Cryocooler: -2 -day pre-cooling and 12 hours for 6 litters liquefaction -3 -day steady operation without any instability Confirmed cryogenic system performance: -Convenient (LN 2 -free Operation…) -Quiet -Stable Cryogenic system is ready for LXe proto-chamber experiment: -next for the first chamber performance test in

17: 03 21 March 2007 Successful ‘First Xenon Liquefaction’ at Nantes! Evidence of successful collaboratio Great Contributions: -Eric Morteau (Electronics) -Patrick Le Ray (Mechanics) -Cyril Grignon (Ph. D student) -Noel Servagent (Xenon Cryogenics) -Jean-Pierre Cussonneau (Simulation) -Dominique Thers (Team Leader) (Nantes)