Author: Zong, Z.G.
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.