1. Cooling Systems Adopted For the Use in the Particle Detectors 1 V. Vacek AGENDA: What we can offer for the the AFP R&D Project: Two cooling systems (Aircooler type – 2 prototypes ready) Thermosiphon laboratory cooling system Cracow, January, 2011V. Vacek, CTU Prague

2. What makes a detector cooling system difficult and different Floating required specification during the design and construction process (both P and T plus power dissipation specifications) Most of the experience and standard parts known for refrigeration industry are excluded due to the working environment Delicate and very expensive evaporators having important supporting task for the detector electronics have to be extremely light, but firm due to the alignment needs Space constrains (unfortunately somehow „shrinking“ during the assembly) limit possibility of insulation and make tube layouts very complex with large number of connectors (leaks …) None or limited accessibility inside the detector during the lifetime of those structures that should exceed several years (10? or more) Interference with other detector sections is to be minimized Too many “experts” involved who are neglecting engineering feasibility Physicists and their demands ….. Cracow, January, 2011V. Vacek, CTU Prague 2

3. What makes a detector cooling system difficult and different Great courage and endless tolerance Solid information and knowledge about thermophysical properties of relevant fluids (fluoroinert family and others … ) Use of the simulation models whenever possible and decent and critical comparison with experimental results Test and verification of all key components Careful scaling up of the cooling system set-up What helps (=CTU) to do a job ….. Now available at CTU for the most fluorocarbons, both via semi-empirical approach and simulation (SAFT EOS, MC and MD simulations) some new SOS experimental data (C 4 F 10, C 3 F 8, CF 3 I and mixtures, CO 2 ), HTC measurements, Henri constant for C 3 F 8 Two phase capillary flow simulation model available (including contamination impact) resulted in less experimental work while tuning capillaries Various experimental cooling circuit were prepared and used by ranging from 200W to 22 kW (with steps at 500W, 1kW, 6 kW) and used for the commissioning of Pixel, SCT of ATLAS and RP of TOTEM prototypes and final design structures Cracow, January, 2011V. Vacek, CTU Prague 3

4. 4 What we are preparing and can offer for the AFP R&D Project Possible cooling system solutions: 1) Modified cooling system, which has a base in TOTEM solution (depending on the available space for the plant) [Compressor-condenser cooling circuit with C3F8] 2) Individual micro-cooling systems close to each of the main heat source unit (tested) see photos 3) Vortex based cooling system (already tested, and two prototypes available) – see photos 4) Modified heat pipes and pulse tube refrigerator solution (with use of already gained experience) see summary slide 5) Thermosiphon cooling lab system – (tested in 2010) – see summary slide PLEASE, TAKE IN ACCOUNT, THAT THIS SUBJECT (COOLING) WAS UNDERESTIMATED FROM THE POINT OF IMPORATNCE, TIMESCALE AND RESOURCES (BOTH IN MANPOWER AND BUDGET) NEARLY IN ALL CERN PROJECT So thanks to our experience, we may still have time to come with an effective solution! Cracow, January, 2011V. Vacek, CTU Prague

5. Vortex tube prototype tests 5 Vortex Tubes are an effective, low cost solution to a wide variety of industrial spot cooling and process cooling needs. With no moving parts, a vortex tube spins compressed air to separate the air into cold and hot air streams. With one stage we can generate dlt T ~ approx. 50 C or more (inlet ~ +17 C cold outlet -50 C @ inlet pressure 8,5 bar; flow ~ up to 1000 l/h) Cracow, January, 2011V. Vacek, CTU Prague

6. AFP R&D Project: Commissioning measurements of the DAC at the Department of Applied Physics of the CTU Prague in July 2009 and 2010 Pilot project with dry air cooling, design phases ~ 17 kg Cracow, January, 2011V. Vacek, CTU Prague 6

7. Vortex tube prototypes 7 1st Prototype 2nd New prototype Two AIRCOOLER Units available in our laboratory: 1st Prototype successfully tested 2nd Prototype is going to be tested this year Cracow, January, 2011V. Vacek, CTU Prague

8. Thermosiphon prototype Thermosiphon in the CTU Prague Lab under the tests Positive results from the tests up to 300 W Similar, but much larger scale is going to be used for ATLAS IBL pixel detector (we collaborate with SLAC and LBL) Cracow, January, 2011V. Vacek, CTU Prague