Large aperture magnets for a future high power proton synchrotron

摘要

A high intensity, high power proton synchrotron is currently underconsideration at Fermilab. The machine known as the Proton Driver -would accelerate 3×10¹³ protons from 400 MeV to 12 GeV(stage I) or 16 GeV (stage II) and ultimately deliver in excess of 1 MWof beam power. To minimize losses and insure beam stability, the spacecharge-induced tune shift must be kept well below 0.5. This isaccomplished by spreading out bunches both longitudinally andtransversely. While the former strategy favors high voltage lowfrequency RF, the latter leads to magnets with unconventionally largeapertures. This requirement, combined with a 1.5 T bending field andrapid cycling operation results in a number of serious but notinsurmountable challenges. In this paper, we discuss the design of theProton Driver magnets and the rationale behind it