Vacuum system design for the 3 GeV-proton synchrotron of JAERI-KEK joint project

Kinsho, Michikazu  ; Nishizawa, Daiji*; Saito, Yoshio*; Suzuki, Hiromitsu; Yokomizo, Hideaki

The 3 GeV synchrotron accelerator for JAERI-KEK joint project is aimed to supply a high-intensity proton beam to both the 50 GeV synchrotron ring and the neutron production target. For this purpose, the 3 GeV synchrotron, having a circumference of 313.5 m, is designed to accelerate a high-power beam of 1MW, by setting 25 Hz as a repetition rate and 8.3 x 1013 as a proton number for each acceleration. A rapid-cycling magnetic field is necessary to operate a synchrotron with such a high repetition rate. Since an eddy-current effect in a metal duct would produce an unacceptable perturbation of the magnetic field and unnecessarily large ohmic losses, an alumina ceramic is a candidate material for vacuum ducts in the dipole and quadrupole magnets. This paper discrives the design for the 3GeV synchrotron of JAWRI-KEK joint project.