Author: Tawada, M.
Paper Title Page
WEPO027 Design Study of Final Focusing Superconducting Magnets for the SuperKEKB 2457
 
  • M. Tawada, N. Higashi, M. Iwasaki, H. Koiso, A. Morita, Y. Ohnishi, N. Ohuchi, K. Oide, T. Oki, K. Tsuchiya, H. Yamaoka, Z.G. Zong
    KEK, Ibaraki, Japan
 
  For SuperKEKB, which is an upgrade project of KEKB, we are studying the design of the final focus quadrupole magnets for the interaction region. The 7 GeV electrons in the high-energy ring and the 4 GeV positrons in the low-energy ring collide at one IP with a finite crossing angle of 83 mrad. For each beam, the final beam focusing system consists of the superconducting quadrupole-doublets. These quadrupole magnets have to meet specifications described below. (1) Because of the small beam separation between two beam lines, the superconducting magnet is designed with thin coils and the conductor size is required to be minimized. (2) Since the beta functions are so large, a large space with a good field quality is required. (3) These magnets must apply the focusing fields on electrons and positrons, independent each other. The quadrupole magnets in the solenoid field of the particle detector are designed without an iron yoke. Consequently, the reduction of the leakage fields from the adjacent beam lines is a critical issue to achieve large dynamic aperture. In this paper we will report the design of final focusing system.