NLC - The Next Linear Collider Project Andy Ringwall 1/9/00 ME 217 NLC Magnet Project Andy Ringwall, SLAC, Liaison Jeff Rifkin, SLAC, Liaison Shun Takai, Coach Vikash Goyal, Coach

ADR 1/9/00 2 NLC - The Next Linear Collider Project Magnets and the NLC Magnets focus and steer charged particle beams –Dipoles, quadrupoles, sextupoles –Electro(EM), permanent(PM) superconducting(SC) –Tolerances: magnetic center, field accuracy and stability, harmonics, vibration 7768 NLC magnets, 93 types –Baseline design calls for nearly all to be EM –EM’s require: magnet, power supplies, power cables, cooling, and utility bill What about using permanent magnets? Electromagnet Quadrupole

ADR 1/9/00 3 NLC - The Next Linear Collider Project Permanent Magnets PM’s eliminate: power supplies, cables, utility costs, physical plant, infrastructure –All PM design –Hybrid PM design(steel pole) PM material choices –Rare earth: Sm-Co, Nd-Fe-B –Ceramic: ferrites(Sr, Ba) –Motors, disc drives, speakers PM issues –Cost –Adjustability –Stability, temp. coefficients –Radiation resistance Permanent Magnet Dipole

ADR 1/9/00 4 NLC - The Next Linear Collider Project NLC Cost Reduction Typical resistive EM: –Magnet:$ 8,700 –Power Supply:$ 24,500 –Cables:$ 16,000 –Power bill/yr:$ 315 Fermi lab recycler ring –Developed a low cost hybrid permanent magnet –$3000/magnet Fermi has started collaborating on the NLC with SLAC PM option is a primary focus area of the collaboration

ADR 1/9/00 5 NLC - The Next Linear Collider Project Hybrid PM Design Example Use ceramic(strontium ferrite) magnets to establish field, similar to Fermi design Change strength using a rotating rare earth(Nd-Fe-B) magnet Achieve 50% gradient adjustment: T/m Design must avoid shifting the magnetic center of the magnet by more than 1 um Reduce instabilities associated with temp. coeff. and radiation resistance Steel PM

ADR 1/9/00 6 NLC - The Next Linear Collider Project ME 217 Goals Apply ME 217 tools to the question of EM vs. PM for the NLC –Review functional requirements as set by the beam physicists and assess how they constrain magnet technology choices –Develop and/or analyze design variants for both technologies –Investigate PM material choices and industrial production base Shin-Etsu, Hitachi, Sumitomo, Ugimag, Vacuumschmelze, others? Capabilities and limitations –Participate in SLAC/Fermi collaboration and prototype development and testing –Contribute input to CDR of September ‘00 Exposure to: material science; electro-, magnetic, and mechanical design; SLAC/NLC, particle accelerators, high energy physics research Students interested in possible summer internships at SLAC next summer and/or a career options at SLAC

ADR 1/9/00 7 NLC - The Next Linear Collider Project PM Options Fixed Strength PM only Variable Strength Fe Pole Variable Strength Fixed Strength Hybrid + rotating PM elements Hybrid + integral trim coil Hybrid Hybrid + stand-alone trim coil Hybrid w/ counter-rotating sections Hybrid + rotating outer PM ring PM segments(Halbach magnet) PM w/ counter-rotating sections Other options?? PM Options, NLC Multipole Magnets