Folie 1

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COOLSB2
Ramped superferric dipole magnet for NESR
Hanno Leibrock, GSI Darmstadt Kick-off meeting
for EU Design Study "DIRACsecondary-Beams" for
the FAIR project April 14-15, 2005
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NESR in FAIR
FAIR Stage 1
versatile storage ring NESR
decelarated beams gt ramped dipoles
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Tasks

• EU FP6 task COOLSB2
• superferric NESR-dipole for 1 T/s ramp rate
• Subtasks
• Magnet layout, yoke design
• Superconducting coil design
• Cryostat design
• gt functioning prototype magnet

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Dipole Parameters
NESR Dipoles
Numbers 24
Maximum field 1.6 T
Minimum field 0.06 T
Ramp rate 1 T/s
Maximum ?B 1.5 T
Bending radius 8.125 m
Deflection angle 15
Effective length 2.128 m
Useable gap width 250 mm
Useable gap hight 70 mm
Real gap height (heating) 90 mm
Field quality ?1?10-4
moderate field (lt1.6 T), large aperture ?
superferric design

• Because
• allows large apertures since the flux is guided
  by the iron and the field quality is defined by
  the pole shape,
• field enhancement by the iron,
• low operation costs

challenges in red !
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Preliminary 2D - design (by C. Muehle)
Nuclotron cable
6000 A, 10 turns, 150 A/ mm2 (coil) curved
(sagitta 69 mm)
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Field distribution
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Field distribution
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SC coil design choice of the conductor

• ramp rate 1 T/s ? low inductance needed ? cable

Nuclotron cable
Rutherford cable
CICC

• eddy currents in helium containment (bobbin)
  and cryostat

• ? 'tube' forced-flow-cooling
• ? 'non'-conducting cryostat

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Gantt diagram for RD with milestones
Milestones
Feasibility studies December 31, 2005 Model
cryostat delivered June 30, 2006 Prototype
dipole delivered December 20, 2007
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Conclusions

• moderate field (lt1.6 T), large aperture ?
  superferric design (low operation costs)
• ramp rate 1 T/s ? low inductance needed ? cable
• a preliminary magnet design exists
• the design of the cryostat has to make sure that
  eddy current effects are negligible
• planned prototype dipole delivery december 2007

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Die Leere
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Advantages of superconducting and resistive
magnets
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Normal conducting CR-dipoles

• Use of the same yoke for the normal conducting
  solution
• gt Problems
• Purcel filter -gt loss of ampere turns
• High flux density in yoke -gt loss of ampere turns
• Small coil window -gt high current density
• gt 465kW power loss per magnet
• Use of an appropriate (enlarged) yoke for the
  normal conducting solution
• No purcel filter, but enlarged pole
• Enlarged yoke for lower flux density
• Enlarged coil window
• gt approx. 200kW power loss per magnet

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Investment costs
Costs for 24 dipoles Normal conducting CR-dipole Superferric CR-dipole
Magnets yoke coil,cryostat, etc. 4880k 2000k 4880k 5763k
Cryogenics (feed boxes, transfer lines) 7 share of 7kW cryo plant Conventional cooling - - ?k 1800k 1260k -
Power supply 1250k 180k
Sum 8130k?k 13883k
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Operation costs
Normal conducting CR-dip. Superferric CR-dipole
Losses at 4.5K (magnets, feed boxes, transfer) - 24x19W456Wcryo
El. power losses 24x465kW11160kW 456Wcryox250W/Wcryo114kW
Operation costs for 20a with 6000h/a and 80 operation of CR and 9 c/kWh 96422k (with optimized nc-solution 200kW/magnet gt up to 2x higher investment 41472k) 984k
Normal cond. quadrupole
El. power losses 26x66kW18x58kW 2760kW
Operation costs 23846k
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Superferric dipole in the A1900 FRS at MSU
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Nuclotron dipole at JINR in Dubna