1. HIGH RAMP RATE SUPERCONDUCTING MAGNETS AT BNL Peter Wanderer BNL Archamps Workshop, March 2003

2. 17 March 2003P. Wanderer2 OUTLINE New facility at GSI  work with BNL to modify RHIC dipoles  1 st magnet test Magnet construction (except superconductor) - Wanderer Quench performance - Wanderer Superconductor R&D – Ghosh Energy loss measurements - Ghosh

3. 17 March 2003P. Wanderer3 GSI NEW FACILITY Use existing machines, add new accelerators, storage ring. –Serve several areas of science –General approval by German Government Construction: Phased approach Superconducting magnets for the highest energy accelerator (SIS200) Last phase of construction

4. 17 March 2003P. Wanderer4 (DIPOLES FOR SIS100) SIS100 may use superconducting magnets too (not discussed further here) PROPOSAL (November 2001) –Superferric, 2T central field, 4 T/sec ramp –Start with Nuclotron design PRESENT –Consider resistive dipoles (see L. Bottura)

5. 17 March 2003P. Wanderer5 DIPOLES FOR SIS200 PROPOSAL (November 2001) –4T central field, 1 T/sec ramp, 5 kW (4.5K) –Modify RHIC design, especially cable –GSI + BNL R&D agreement PRESENT (SIS300) –Physics: 6T, not 4T  2 layer coil –Looking at UNK magnets

6. 17 March 2003P. Wanderer6 BNL + GSI collaboration GSI: G. Moritz, J. Kaugerts BNL: M. Anerella, A. Ghosh, R. Soika, P. Wanderer Consultants: M. Wilson, W. Hassenzahl

7. 17 March 2003P. Wanderer7 Magnet (1m): coil & collars Coil wedges: G11, not copper Coil oversize by ~ 25  m/turn  reduce pole shim by.88 mm & modify ends Collars: assemble 15cm-long packs with G10 tubes instead of brass tubes Collars: G11 keys (except for 2 cm)

8. 17 March 2003P. Wanderer8 Magnet: laminations –GSI procurement –BNL drawing –0.5 mm thick –Si steel –Coated both sides with B-stage epoxy –Glued into 25.4 cm-long blocks (10 blocks)

9. 17 March 2003P. Wanderer9 Magnet: yoke, shell, splice Yoke – axial support from ss rods inside G10 sleeves; SS nuts and G10 washers at the ends Yoke top-bottom alignment: G10 keys Shell: weld backing strip loose Ramp & Splice between top & bottom coils – no change from RHIC/LHC

10. 17 March 2003P. Wanderer10

11. 17 March 2003P. Wanderer11 Quench studies Quench - standard ramp rate (.05 T/s) –Quench until greatly exceed 4T (6.7kA) Quench at 1-2 T/sec –5 kA power supply heavily modified fast ramping down ramp is mirror of up ramp –Reach 7.5 kA by ramping fast and minimizing time at I max

12. 17 March 2003P. Wanderer12

13. 17 March 2003P. Wanderer13 CONCLUSION & PLANS Conclusion: magnet greatly exceeds design field & ramp rate.. a success Plans: –Measure field quality  new measuring system … later this year –Test magnet w. unvented cable –Further cable improvements –Test magnet in forced flow (supercritical)