Dipole Magnets for NESR and RESR Gebhard Moritz GSI Darmstadt November 2004

Dipole Parameters Numbers 24 Maximum field1.6 T Minimum field0.06 T Ramp rate1 T/s Maximum  B 1.5 T Bending radius8.125 m Deflection angle15° Effective length2.128 m Useable gap width250 mm Useable gap hight70 mm Real gap height (heating)90 mm Field quality  1  RESR Dipoles Numbers 24 Maximum field1.6 T Minimum field0.35 T Ramp rate1 T/s Maximum  B 1.1 T Bending radius8.125 m Deflection angle15° Effective length2.128 m Useable gap width250 mm Useable gap hight70 mm Real gap height (heating)90 mm Field quality  1  NESR Dipoles challenges in red !

Consequences 1.6 T, large aperture → superferric design → CR-dipole, SuperFRS-dipole

Consequences 1 T/s → low inductance needed → cable eddy currents in helium containment (bobbin) and cryostat → 'tube' forced-flow-cooling → 'non'-conducting cryostat

preliminary 2D- design (by C. Muehle) ab c d from CR dipole design (Wang, Kalimov) 6000 A, 10 turns, 150 A/ mm^2 (coil) curved (sagitta 69 mm)

field distribution in the coil

preliminary cryogenic design for NESR (by Y.Xiang) He transfer Lline of NESR He transfer line from CR/RESR Hall 4.5 K (V) Feed line for six dipoles 4.5 K (R) 40 K (V) 80 K (R) From ring transfer line

preliminary cryogenic design for RESR

Conclusions superferric dipole looks feasible resistive alternative is also possible –decision according to costs (investment vs. operating costs) R&D cryostat design choice of the cryogenic design (minimization of the costs) part of the EU FP6 design study