1. MTA Cryostat & cooling loop design Christine Darve Fermilab/Beams Division/ Cryogenic Department/ Engineering and Design Group Preparation of the Mucool/MICE review 02/11/03

2. February 11 2003CDMTA Cryostat and cooling loop design MTA cryo-system - Specifications BD/Cryogenic Department FERMILAB Remove up to 150 Watt of energy loss from LH2 P= 1.2 atm, T= 17 K  < 5%  T~ 1 K (could be 3 K) Safety requirements: 1. “ Guidelines for the Design, Fabrication, Testing, Installation and Operation of LH2 Targets–20 May 1997”, Fermilab by Del Allspach et al. 2. Fermilab ES&H (5032), 3. code/standard ASME, NASA, 4. NEC (art 500) 5. CGA

3. February 11 2003CDMTA Cryostat and cooling loop design MTA cryo-system - Materials 1. Caltech LH2 pump Max LH2 mass-flow = 450 g/s (0.12 MPa, Tin=17 K)  P total < 0.36 psig References : 1. “A high power liquid hydrogen target for parity violation experiments”, E.J. Beise et al., Research instruments & methods in physics research (1996), 383-391” 2. “ MuCool LH2 pump test report”, C. Darve and B. Norris, (09/02) BD/Cryogenic Department FERMILAB 2. Cryo department refrigeration system Max He mass-flow = 27 g/s (0.2 MPa, Tin=14 K)  T=3 K for 450 W (17 K, 0.12 MPa) Reference : 1. “Results of the MuCool Expander Flow Tests Performed at the Meson Cryogeni Test Facility”, A. Martinez and A. Klebaner, (12/02)

4. February 11 2003CDMTA Cryostat and cooling loop design BD/Cryogenic Department FERMILAB Part V – A look at the Hydrogen Proposal Cryo-system design- Pressure drop calculation RECALL from Internal review (09/24/02) If m=450g/s and 32 nozzle dia. = 0.6” then Maximum allowable  P = 0.364 psi Total  P calculated=> 0.203 psi 0.011 psi 0.031 psi 0.027 psi 0.011 psi 0.036 psi 0.078 psi Will a velocity at the nozzle equal to 2.5 m/s be enough for ionization cooling?

5. February 11 2003CDMTA Cryostat and cooling loop design BD/Cryogenic Department FERMILAB Flow Simulation by Wing Lau/ Stephanie Yang/ Charles Holding (Oxford) MTA cryo-system – Cryoloop Design TT Heat transfer coeff. Given geometry, Power and nozzle distribution mass flow PP Oxford studies: 1.Simulate the current MTA manifold geometry 2.Simulate beam at 150 W (volume, ø10mm (3 sigma gaussian)) 3.Calculate heat transfer coefficients and temperature distribution for MTA conditions (  V ~ 0.5 m/s – 4 m/s) Velocity at nozzle

6. February 11 2003CDMTA Cryostat and cooling loop design MTA cryo-system – Cryostat Design 1. Cryostat assembly: Vacuum vessel: MAWP=25 psig; SS, IPS 16 Sch10, IPS 50 Sch10  Dome (SS, 10 mm)  Plate (SS, 10 mm) Thermal shield +MLI (Al, Mylar) Piping (SS, IPS 1, 2) Helium buffer(SS,  3) Vacuum window(Al) Safety devices (see internal review) BD/Cryogenic Department FERMILAB 2. Heat exchanger assembly Coil (copper,  0.55in) Outer shell (SS, IPS6) 3. LH2 pump assembly LH2 pump and shaft with foam Motor outer shield

7. February 11 2003CDMTA Cryostat and cooling loop design Pressure relief valve – LH 2 : II C 4 a (iii) Relief pressure (10 psig or 25 psid) Sized for max. heat flux produced by air condensed on the LH 2 loop at 1 atm. 2 valves ACGO=> 0.502 in 2 ASME codeRedundant Capacity = 52 g/s Pressure relief valve – Insulation vacuum : II D 3 MAWP (15 psig internal) Capable of limiting the internal pressure in vacuum vessel to less than 15 psig following the absorber rupture (deposition of 25 liter in the vacuum space) Vapor evaluation q= 20 W/cm2 Take into account DP connection piping and entrance/exit losses 3 parallel plates (FNAL design)=> 2” ASME codeRedundant Capacity = 197 g/s Relief system must be flow tested BD/Cryogenic Department FERMILAB Part V – A look at the Hydrogen Proposal To meet the standard RECALL from Internal review (09/24/02)

8. February 11 2003CDMTA Cryostat and cooling loop design 4. Absorber assembly: Ed Black/Wing Lau windows and manifold design Interface of the systems Bimetallic junction Indium Doubled-seal 5. Supporting system G10 spider 6. Instrumentation P: Penning,  P T: Cernox Flowmeter, Heater Valve (elec, pneum, manual..) Turbomolecular pump (N2 guard) BD/Cryogenic Department FERMILAB MTA cryo-system – Cryostat Design Minimum spark energies for ignition of H 2 in air is 0.017 mJ at 1 atm, 300 K Lower pressure for ignition is ~1 psia (min abs. 0.02 psia // 1.4 mbar)

9. February 11 2003CDMTA Cryostat and cooling loop design Cryostat design Focus : Final cooling system Implementation of the vacuum windows Heater implementation (Helium side) Supporting system Instrumentation implementation BD/Cryogenic Department FERMILAB MTA cryo-system – Conclusions Cooling loop Focus: Thermo-hydraulic behavior inside LH2 absorber for which  T=1 K: geometry and nozzle, power distribution, mass flow ==>  P Validation of optimization to  T and  P as specified

10. February 11 2003CDMTA Cryostat and cooling loop design 1. Sealing for vacuum window: Teflon O’ring, Indium sealing, copper gasket (Radiation hardness) 2. Cryopumping (turbo-molecular pump, thermal shield) 3. Distribution of RFs and magnets around cryostat: interface atmosphere or vacuum behind cryostat vacuum window 4. Supporting system and absorber position in magnet 5. Who design cryostat support in hall? 6. Absorber Instrumentation routing and port 7. ….. BD/Cryogenic Department FERMILAB MTA cryo-system – Questions

11. February 11 2003CDMTA Cryostat and cooling loop design BD/Cryogenic Department FERMILAB Part V – A look at the Hydrogen Proposal Process and Instrumentation Diagram RECALL from Internal review (09/24/02)

12. February 11 2003CDMTA Cryostat and cooling loop design BD/Cryogenic Department FERMILAB Part IV – A look at the Windows and Absorber Vessel LH2 Manifold absorber (by E. Black) RECALL from Internal review (09/24/02)