Recent Progress Designing Compact Superconducting Final Focus Magnets for the ILC

摘要

QDO, the final focus (FF) magnet closest to the interaction point (P) for the ILC 20 mr crossing angle layout, must provide strong focusing yet be adjustable to accommodate collision energy changes for energy scans and low energy calibration ruling. But it must be compact to allow disrupted beam and Beamstrahlung coming from the IP to pass outside into an independent instrumented beam line to a high-power beam absorber. The QDO design builds upon BNL experience making direct wind superconducting magnets. We present test results for a QDO magnetic test prototype and introduce a new shielded magnet design, to replace the previous side-by-side design concept, that greatly simplifies the field correction scheme and holds promise of working for crossing angles as small as 14 mr.