1. Superferric quadrupoles and multipoles at the NSCL Al Zeller NSCL/MSU

2. NSCL Coupled Cyclotron Facility Experimental Areas Cyclotrons – up to  =0.6 for A<100 ECR Operational – Study N=82 nuclei and nuclei along the neutron drip line up to mass 30. R. York, F. Marti, T. Grimm et al.

3. A1900 K500 Coupling line K1200 Target A1900

5. Low current operation: Quads – 100 A (except 2 @ 450A Dipoles – 200 A Sextupoles – 40 A Octupoles – 20 A

6. Standard NSCL quad design used in the A1900.

7. Schematic of A1900 triplet

8. A1900

9. A1900 quad with sextupole and octupole inserts. All cold. Multipoles mounted on bore tube.

10. 8 triplets – 4 unique ones 16 quads have multipole inserts Sextupole largest radius inside pole tips Octupole smallest radius

11. Multipole inserts in a quad From Carsten Muehle (April 2003)

12. Sextupole on

13. A1900 Multipole coils

14. Inserting multipoles into quad triplet.

15. A1900 Insert into the helium vessel

16. A1900 multipoles Typical multipole values: Sextupole – 280 turns of 0.66 mm wire 43 x 5 mm J eng = 52 A/mm 2 @ 2 T Octupole – 280 turns (same wire) 35.6 x 5 mm J eng = 32 A/mm 2 @ 2 T

17. A1900 Quad mapper Mapper tube to which 3 Hall probes attached at different radii

18. A1900

19. Octupole map note nice symmetry Sextupole map note dipole term

20. A1900 Quadrupoles change effective length with excitation!

21. Multipole inserts in a quad From Carsten Muehle (April 2003)

22. Forces on Carsten’s magnet

23. A1900 In operation since 2000. No magnet failures Heat load: Quad triplets ~ 2 W each Valves and transfer lines ~ 75 W 2 of the dipole have about 3 W One dipole has a nitrogen leak and about 30 W One dipole has high nitrogen shield temp and is about 20 W Total heat load = 150 W (Plant capacity ~ 2 kW)

24. All coils self-protecting All the large quads quenched multiple times in testing Multipole coils have never quenched unless quad quenched first

26. S800

27. S800 sextupole Checking S800 Q2 sextupole with go-no go gauge

28. Presently ~ 70 superferric quads Building a radiation resistant quad using metal oxide CICC and warm iron

29. Inserts versus stand-alone multipoles Coil winding very easy and fast Assembly onto bore tube very labor intensive Generally, putting magnets in cryostat is time consuming. More magnets in a single vessel is cheaper.