MOLLER Hybrid Toroid Engineering Design

Transcription

1 MOLLER Hybrid Toroid Engineering Design Presented by Ernie Ihloff, MIT-Bates With Contributions From: Jim Kelsey, MIT-Bates Jason Bessuille, MIT-Bates Presented to MOLLER Collaboration Thursday, 8 th May, MAY2014 1

2 Overview Coil Design Overview Site Infrastructure Support structure design status Vacuum chamber status Coil Fabrication Tasks going forward 08MAY2014 2

3 Coils Overview Out-of-plane bends Encapsulated coil shown with aluminum inserts. These inserts will be over-wrapped with the coil ground wrap and cured with the encapsulant Coil cross section showing all 76 turns, 11 pancake shapes, and tentatively chosen conductor With ½ of the encapsulant removed, you can see the out-of-plane bends on pancakes 3R, 2R, and 1BR. Coil Mass 186 kg Carrier Mass 1039 kg Centering Force lbf kgf Current 384 A Coil Voltage Drop <300 V Conductor Length / coil 775 m Number of Turns 76 turns Cooling Circuits / Coil: 17 paths Water Flow / Coil: lpm 10.5 gpm Water Flow / Toroid: lpm 73.4 gpm Maximum Pressure: 16.7 atm psi Water Temp in / out 20 / 60 o C 08MAY2014 3

4 Hall A LCW Water System: 500 GPM 250 psi 85 F (29 C) supply / 110 F (43 C) return Hall A Infrastructure Magnet cooling A separate Moller magnet cooling system is required Must isolate local water from site water to prevent activated water getting topside Will include chiller to reduce LCW supply to C and maintain to within a few degrees Will supply cooling to upstream torus, hybrid, and collimators. Hall A Power Currently 0.86 MVA available Estimate Hybrid alone will use 775 kw Additional substation and power drops being installed for 2 MVA Hall A Crane 20 Ton capacity Sufficient for assembling coils into support structure and loading into vacuum vessel Combined toroid + vacuum vessel might be above 20t, but no plans to move them together with crane 08MAY2014 4

5 Hall A Infrastructure Coil thermal analysis was presented at Collaboration meeting in June. Water temperatures fixed at 20 C supply / 60 C return. We discovered that a separate pump / chiller would need to be located between magnet and site water, so pressure drop can be higher and temperature can be lower than LCW (site) water Added benefit of segregating potentially activated coolant in the hall. Junction box at existing power penetrations LCW Water (currently necked down from ~8 to ~4 ) New power penetrations Penetrations for second surface transformer, and LCW lines. These will be converted to continuous large pipe (~8 ) all the way to the floor of the hall. 08MAY2014 5

6 Latest Frame and Carriers 08MAY2014 6

7 Frame Analysis σ vm = MPa 23Jan2014 New model using commercially available aluminum members. Bolts not included, but link connectors are. Forces include gravity, magnetic forces (3000 lbf) and coil weight. δ = mm 08MAY2014 7

8 Carrier Analysis Both vertical and horizontal orientations are considered Loads include gravity (approx kgf for carrier and 250 kgf for coils) and magnetic centering force (3000 lbf) Boundary conditions based on 6-strut kinematic support Phi + Z X + Y X + Y Solid mesh for study that incorporates carrier assembly + coils Boundary conditions for carrier analysis. Blue arrows denote fixed translational degrees of freedom from struts. Red arrows indicate components of gravity vector. Note: Both end pins are co-axial. All 3 pin axes intersect predicted CG of coil+carrier assembly. Stress analysis in which bolted joints are modeled. Horizontal orientation, showing Factor of Safety (areas between FoS = 2 and FoS = 50) 08MAY2014 8

9 Carrier Analysis Selected Deflections 2.08 mm 2.41 mm Sept (V2) Horizontal Sept (V2) 25.8 deg ( vertical ) mm mm Nov 7 (R9) includes upstream added material and side rib Nov 7 (R10) Moved R supports outwards, moved end phi supports inwards 08MAY2014 9

10 6-Strut Support Links Strut Links Current Design Length: 450 mm n.b. - Typical allowable angle ß=8.5 08MAY

11 Vacuum Chamber Aluminum chamber with reinforcement. Weight approx. 19,000 lbf (8,600 kgf) Upstream and Downstream flanges have appropriately sized ports to provide no interference for particles. Pumping ports on underside Will likely require cryo-pumps due to outgassing rate. Large seals will be differentially pumped elastomer o- rings. Services for the toroid will all come through the top plate. Visited local vendor Dynavac (MA) Suggest using cryogenic panel pumping on walls inside 77 K. Offers up to 11 litres/s/cm 2 pumping speed for H MAY

12 Chamber FEA Applied loads include self-weight of chamber (~19,000 lbf), external pressure (1.0 atm) and weight of toroid assembly supported on top plate (20,000 lbf) End blankoff flanges included for analysis These add to overall pressure load but must be used for initial testing. Maximum deflection on top plate is.059 (1.5 mm) Maximum global deflection is 3 mm on side plates Stress has a safety factor of 2 against yield (6061-T6 aluminum) The yield stress limit is 240 MPa and 105 MPa across welds. Stress obtained from finite element analysis indicates maximum stress levels at 120 MPa and stress levels of 60 MPa near the welded sections. 08MAY

13 Coils Fabrication We conducted a site visit to Everson-Tesla in Nazareth, PA General impressions: Clean, professional shop Does excellent work on major projects demonstrates relevant expertise Cyclotrons Train motors USN Advanced Arresting Gear for aircraft carriers Beam optics for industry and academia. BLAST toroid coils Feedback: They offered some advice on the bonded coil inserts (see following slide) Suggest to use bisphenol-a-based epoxy, rather than cyanate-based. Need information on radiation dosage Example is CTV-101k Agree with our plan to use Double-Dacron Glass (DDG) as conductor insulation Need more tolerances Planarity Coil position tolerance (of bulk coil package relative to datum, not interconductor; c.f mm is tight) They expect this project will take ~1 year from order placement to completion. 08MAY

14 Coils Fabrication Vendors offered some advice on the bonded coil inserts Would prefer these to completely fill the holes Used as winding form / die Agree with our plan to overwrap these and co-cure with coil assembly We ve built a 1:6 scale model of the coil at Bates to gain some insight into winding strategy. Shown above: coil model with first pass at full-coverage inserts. They are currently modeled as aluminum weldments. Plan to replace lip with removable plate so as not to increase width of assembled coil. 08MAY

15 Tasks Going Forward FY Redesign coil package based on vendor feedback. 2. Incorporate collimators into design of hybrid magnet. 3. Incorporate changes from collimator design into the design of the hybrid magnet and support frame package. 4. Incorporate changes from item 3 into vacuum chamber design. Complete design of vacuum chamber with drawings for competitive bid. FY Design supports for vacuum chamber to integrate into Hall A to accommodate 10 beam height and use appropriate floor loading 6. Design of vacuum system for vacuum chamber and preparation of documents for competitive bid. 7. Specify hybrid magnet power supply and obtain bids 8. Design secondary cooling loop for interface to JLab LCW system. 08MAY