MICE LH2 Operating Parameters Mary Anne Cummings MICE October ‘02 LBL Oct. 24, 2002

This session 1.Baseline for the Nov. 25 th deadline proposal established this meeting 1.Absorber Design 2.Integration with experiment 3.Instrumention 4.Safety 2.Budget will be presented by Edgar Black 3.Timeline will be presented by Shigeru Ishimoto 4.Mucool to MICE intersection

Questions 1.What are the cooling experiments going to be? 1.No absorber/Different absorber fillings/variable lengths 2.Solid absorber/emittance exchange 3.Focussing magnets: solenoidal/gradient/ different field strengths 2.What comprises an “upgrade” program? 3.Safety requirements vs. performance 1.No. of windows – no. of volumes 2.Restrictions on instrumentation 4.What are the heat loads on the absorber? 5.What is the instrumentation around/near the absorber? (e.g., tracker readout, magnetic field measurements, absorber instrumentation, safety monitors..) 6.What is the FNAL MTF/MICE RAL interface?

Baseline/``Plan B” 1.Convection absorber prototype (R=15cm, L max = 34cm) Convection absorber some other longitudinal dimension 2.Absorber filled with LH2 Absorber filled with LHe, force-flow 3.Absorber focussing coils in gradient mode, full power Gradient mode at lower power 4.Full monitoring instrumention for LH2 External LH2 probes only 5.Separate refrigeration line for LH2 system LHe filled, will come off the LHe circuit 6.Instrumentation for mag. field inside LH2 External Hall probes

Current projects at FNAL *** directly contributes to MICE final absorber design 1.New “bellows” window design, manufacture and quality assessment *** 2.Vacuum window certification tests and FEA comparison *** 3.Three-dimensional flow simulations: “force flow” and convection to assess temperature and density uniformity *** 4.Absorber instrumentation and data acquisition *** 5.Flow tests: 1.FORCE FLOW: NIU prototype/Black Infrared setup 2.CONVECTION : KEK prototype (non-LH2 cryo) *** 6. Schlieren/Ronchi tests at ANL *** 7.MTF (FNAL Linac) area design and cryogenic integration 8.MICE cooling cell design and cryo integration 9.Staging of absorber tests at MTF *** 10.Strain tests of absorber in magnet (ramp up/down/quench) *** 11.Fun with LH2 in magnetic fields..B field measurements ***

LH2 MICE Safety Issues O2/LH2 separation No Ignition sources near LH2 Adequate ventilation Affects: Windows: absorbers and vacuum Primary and secondary vacuum volumes Support structure absorber/focussing coil Instrumentation (experiment and monitors) Cryogenic operation Laboratory area Cooling concerns: 1.Minimizing window thickness/no. of windows 2.Uniform heat maintenance of LH2 Mucool contribution MICE-specific

Absorber/magnet Windows (vac./abs.) Flow/convection sims. Instr. and data acq Schlieren/Ronchi Flow tests: MTF (FNAL Linac) MICE Absorber/Solenoid tests LH2 Mucool => MICE MTF occupancy? Yr Yr. 200X Convection: Force flow: MTF LH2 Yr. 2003

MICE LH2 R&D: Proposal to Program 1.We have established a viable R&D program to produce a MICE absorber integrated into a focussing coil 2.Mucool program, both pre- and post MTF “occupancy”, and pre and post MTF beam is making direct contributions to the MICE prototype, and will continue with cooling component optimisation; 1.Windows 2.Flow tests 3.Instrumentation/ data acquistion 4.LH2 in high magnetic fields 3.Mucool and MICE are complimentary experiments – can maximize the productivity of all LH2 participants 4.The dual Mucool/MICE “citizenship” means that the two flow designs will be studied in parallel with both physics (MICE) and engineering (MTF) concerns being addressed – possible hybrid for a real cooling channel likely

Programs toward MICE 1.Window design/manufacture and certification 2.Absorber manifold development/tests 3.Absorber instrumentation/ data acquisition Ongoing Mucool project contributions: MICE specific physics and engineering problems: 1.Focussing-coil/LH2 absorber assembly 2.Magnetic field determination in LH2 3.Cooling channel instrumentation integrated with LH2 absorber

Cooling channel requires minimum “heating”  Low Z material  maximize radiation length  Minimize window thickness/Z while retaining structural integrity  Nonstandard window design Absorber Heat Management  Refrigeration: W heat deposition from beam (~8W/cm)  Temperature and density stability: LH2 circulation  Novel flow and convection schemes Mucool LH2 Absorber Issues emittance eqn.: Design/test drivers: Figure of merit: . dE/ds. 2mL