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LARP Collimator Engineering. E. Doyle 2/3/05. Review: SS Thermal Simulation. beam. 150mm OD 25mm wall Simply supported Heat: 1hr beam life, FLUKA results, 10x10x24 rectangular grid mapped to cyl I.D. water-cooled 20C h=11880 W/m^2/C No heat transport by water. Cu, 61C. support.
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LARP Collimator Engineering E. Doyle 2/3/05
Review: SS Thermal Simulation beam • 150mm OD • 25mm wall • Simply supported • Heat: 1hr beam life, FLUKA results, 10x10x24 rectangular grid mapped to cyl • I.D. water-cooled 20C • h=11880 W/m^2/C • No heat transport by water Cu, 61C support dx=221 um support
12/2 meeting: ANSYS Simulation Results • Alternative alloys (Inconel, Invar, Al) yielded little or no improvement in distortion (assuming uniform cooling of ID) • Proposed that helical water flow might distribute heat to far side of bar, reducing distortion • New results • Helical water flow contributes to thermal distortion by cooling far side of jaw, increasing DT through the jaw • Preferable to cool beam side of jaw only, allow far side to heat up
Simulation: Cooling limited to arc centered near beam allows far side of jaw to warm up. Peak temperature higher but distortion less. • For Cu cylinder, Steady State results: • TSS: 61C => 89C • d : 220um => 79um O.D. 45 deg arc – 195C, 111C beam I.D. SS initial condition
360o cooling of I.D. 45o cooling arc Note transverse gradient causes bending Note axial gradient 61C 89C Note more swelling than bending support dx=221 mm Spec: 25mm dx=79 mm support
Mechanical distributor for directing coolant to axial channels
Distributor & “Hard Wired” coolant channel concepts Free wheeling distributor – orientation controlled by gravity or external magnetic device – always directs flow to beam-side axial channels whatever the orientation of the rotor. Six or more discrete axial flow paths. Individual flexible supply tubes. One or more may be activated for a given rotor orientation. Flow control valves external to vacuum chamber.
Alternative distortion control • Machine jaw with slightly concave hourglass shape. Thermal distortion => flat • Divide jaw lengthwise in two independent sections (distortion proportional to L2) • Heat far side of jaw (feedback control?) to minimize DT • Custom alloy combining low-Z high conductivity with high-Z material
Designer Alloy Concept • Low-Z, high conductivity material matrix with distributed high-Z material • Cu in Be or Al • Be is powder metallurgy product. Any ratio is possible. • 2219 Al: standard alloy with 6% Cu content. • Investigating higher Cu content alloys Notes: 1. Pure Al 2. 6% Cu
2219 Al, cooled on 45o arc of ID beam • 1 hr beam life SS • 4.6 kW heat absorbed • More swelling than bending 42.7C dx=30.6 mm