MEIC Shifting Magnet Tim Michalski August 6 2015

MEIC Shifting Magnet Tim Michalski August 6, 2015 1

Arc Chicane Using current 22. 8 m FODO cell design (8 m 3 T dipoles with 3. 4 m separation) One chicane per arc (also helps with synchronization of the 2 nd IP), one extra FODO cell per arc Takes up cells, which could otherwise be used for chromaticity compensation x = 52 cm x = -69 cm Total bending angle and z length are fixed 10 cm Radial movement range +52 / -69 cm Maximum change in magnet spacing 20 mm 6 dipoles, 7 quads 10 cm +36 / -39 cm 14 mm 8 dipoles, 9 quads 10 cm +28 / -29 cm 11 mm # of FODO cells # of magnet moved Path length change 3 4 dipoles, 5 quads 4 5 2

Concept Layout of Superferric Arc Half Cell Magnets 3

Magnet Interconnect From LHC (Superferric Magnets Will Be Similar) 4

Considerations for Repositioning Superferric Magnets • Moving radially inward and outward is feasible • Use slides and measurement scheme to make repeatable • Rotation of magnets will be required as well • Considerations for interfaces between magnets and to outside world • Beamline Vacuum – bellows between adjacent beam pipe vacuum chambers • Insulating Vacuum – bellows between adjacent Arc Half-Cells (? ) • Power – “service loop” for conductors • Cryogens – may require flex hoses between adjacent Arc Half-Cells and assessment of U-Tubes 5

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Considerations for Repositioning PEP-II Magnets • Moving radially inward and outward is feasible • Use slides and measurement scheme to make repeatable • Rotation of magnets will be required as well – if doing a short string • Considerations for interfaces between magnets and to outside world – no major issues • Vacuum – assess capacity to expand/contract RF shielded bellows between rafts • Potential to use different bellows for different energies • Current design architecture has the Electron Collider Ring suspended above the Ion Collider Ring 7

Considerations for Repositioning PEP-II Magnets Length of Bellows is. 125 m or 4. 92” With a single bellows in a Arc Half. Cell, Raft and Dipole must be moved as a pair. Location of Bellows With Corrector Without Corrector 8

Super. KEK B and PEP-II HER Shielded Bellows PEP-II HER Bellows 9

Potential Positioning Systems 10