1. Close Cycle Dilution for Space Ph. Camus, G. Vermeulen, G. Chaudhry, A. Benoit, F. Martin B-POL Workshop, IAP Paris, 29th July 2010

2. Planck Open Dilution System

3. Planck System Performances Planck system provide 1.6K and 100mK cooling stages from a 4.5K cooler Cooling power of 400  W @1.6K and 0.2  W(*) @100mK Isotopes flow of 18  mol/s 4He and 6  mol/s 3He Needs HP (285 Bar) storage ( 4 X 50L ) for 2 years Critical pneumatical system for flow control and maintain a high purity Full integration of the heat exchanger with the focal plane and the wires ( thermalization ) (*) + thermalization power of the FP supports and the wires between 1.6K and 0.1K

4. CCDR Concept

5. Separation and performances at high 4He flow (F.Martin PhD thesis, 2009)

6. BLISS Study Mass Budget – Cold H/W (including IOB)< 150 kg 50 kg for SAFARI Thermal Budget – 15 mW @ 4.5 K (FPI Total) – 5mW @1.7K (FPI Total) Volume FPI Position Warm Electronics

7. Double stage ADR solution Grating Spectrometers + screens > 9kg at 50 mK ! 0.4  W at 50mK

8. Carbon fiber supports Advantage to C/F rods

9. 4K stage 1.7K stage 300mK stage 50mK / instruments C/F rods Screens Heat intercept between 300-50mK 200  mol/s 4He 30  mol/s 3He W/O locking system for launch !

10. System aspects Cryo device integrated functions : -Cooling detectors -Instrument support -Part of the read/out chain (cables thermalization / cold amplifiers ) ? 3Helium circulation (30  mol/s - 5/200 mBar) Cold pump Room temp pump Isotopes storage Integration (Planck-like)

11. Solutions for 3He pump Space qualified mechanical pumps – JAXA JT3HE compressor adaptation – Thales PT compressor adaptation – High speed drag pump Cryo pump – Twente development for Darwin => The two options will kept

12. High speed drag pump Creare technology (space qualified) Technical proposal under discussion 200000 RPM Gas bearing Adixen commercial product CEA/AirLiquide design study 60000-120000 RPM Mag bearings

13. Cryogenic pump Darwin H2 JT system Design adaptation for the dilution Need a check valve adaptation for low pressure Acceptable heat load at 15K/50K (100mW)

14. Conclusions Cooling performances achieved 1  W @ 50mK (TRL3-4) Re-use of the BLISS case for B-POL Need to have a complete engineering model – 0 G still demonstration – Pump choice / development (prob. Two solutions) Supported by Cnes (PhD A. Volpe) and ESA (ITI) Objective TRL4 in June 2011