Fabrication of a Molded Type High Power Septum Magnet.

Abstract

A couple of pulse septum magnets is used to inject a 800MeV electron into the superconducting electron storage ring of Mitsubishi Electric Corp. The beam orbit simulation indicates that the apparent septum width of the magnet should be less than 3mm to obtain the good injection efficiency into the ring. To perform the requirement and overcome the problems of heat dissipation and Lorentz force, the molded type septum magnet is designed and fabricated.The fabricated magnet is 1m long and has an aperture of 10mm height and 10mm width. The vacuum pipe of 0.3mm thickness is settled through the aperture for beam transport line (HBT line). The magnet is excited by a single turn coil to 1.8T at 17kA of a sine wave with a width of 4ms which provides a peak field uniformity of 0.1% for a duration of 12μs as required for injection.As for the apparent septum width, the width of 2.5mm, which includes the coil, coil holder, and thickness of the vacuum chamber of storage ring and HBT line, is achieved.The experiment of high energy electron beam transportation through the magnet has been done and the stable extraction from the magnet is observed.