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

COOLSB2 COOLSB2

NESR in FAIR NESR in FAIR

FAIR Stage 1 versatile storage ring NESR

decelarated beams => ramped dipoles

TasksTasks

EU FP6 task COOLSB2:

superferric NESR-dipole for 1 T/s ramp rate

Subtasks:

Magnet layout, yoke design

Superconducting coil design

Cryostat design

=> functioning prototype magnet

Dipole ParametersDipole Parameters

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 110-4

NESR DipolesNESR Dipoles

challenges in red !

moderate field (<1.6 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

Preliminary 2D - design Preliminary 2D - design (by C. Muehle)(by C. Muehle)

6000 A, 10 turns, 150 A/ mm2 (coil) curved (sagitta 69 mm)

Nuclotron cable

Field distributionField distribution

Field distributionField distribution

SC coil design: SC coil design: choice of the conductorchoice of the conductor

ramp rate 1 T/s → low inductance needed → cable

eddy currents in helium containment (bobbin) and cryostat

• → 'tube' forced-flow-cooling

• → 'non'-conducting cryostat

Nuclotron cable Rutherford cable CICC

Gantt diagram for Gantt diagram for R&DR&D with milestones with milestones

Milestones: Feasibility studies: December 31, 2005

Model cryostat delivered: June 30, 2006

Prototype dipole delivered: December 20, 2007

ConclusionsConclusions

moderate field (<1.6 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

Die LeereDie Leere

Advantages of superconducting and Advantages of superconducting and resistive magnetsresistive magnets

superconducting resistive high current density → small coil size, small magnet size,

no Helium supply (refrigerator, supply lines, distribution boxes, feed-boxes)

zero resistance→ low operational costs, cheap amp-turns, low cost power supplies

no Helium containment, no (complicated) cryostats

high field magnets possible no quench detection / protection no water cooling necessary no R&D necessary cryogenic pumping

Formatiert: Kopfzeilenabstandvom Rand: 1,25 cm,Fußzeilenabstand vom Rand: 1,25 cm

Formatiert: Schriftart: 14 pt

Formatiert: Schriftart: 14 pt

Formatiert: Schriftart: 14 pt

Formatiert: Schriftart: 14 pt

Formatiert: Schriftart: 14 pt

Formatiert: Schriftart: 14 pt

Normal conducting CR-dipolesNormal conducting CR-dipoles

•Use of the same yoke for the normal conducting solution

•=> Problems:

•Purcel filter -> loss of ampere turns

•High flux density in yoke -> loss of ampere turns

•Small coil window -> high current density

•=> 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

•=> approx. 200kW power loss per magnet

Investment costsInvestment 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€

Operation costsOperation costs

Normal conducting CR-dip. Superferric CR-dipole

Losses at 4.5K (magnets, feed boxes, transfer)

- 24x19W=456Wcryo

El. power losses 24x465kW=11160kW 456Wcryox250W/Wcryo=114kW

Operation costs

for 20a with 6000h/a and 80% operation of CR and 9 c/kWh

96422k€

(with optimized nc-solution 200kW/magnet => up to 2x higher

investment:

41472k€)

984k€

Normal cond. quadrupole

El. power losses 26x66kW+18x58kW = 2760kW

Operation costs 23846k€

Superferric dipole in the A1900 FRS at MSU

Nuclotron dipoleNuclotron dipole at JINR in Dubna at JINR in Dubna