One-Third Resonance Extraction from INS AG Electron Synchrotron

Abstract

Slow beam extraction from the INS-AG electron synchrotron was done by using a one-third resonance of the betatron oscillation. A current strip was used to change the number of the radial betatron oscillation per revolution from 2.25 to 7/3 and to enlarge the amplitude of the oscillation. The extracting beam orbit was analysed using an approximate Hamiltonian which has a separatrix represented by three straight lines and the result was in good agreement with that pursued by a computer. The properties of the extracted beam were as follows; The efficiency was 50% for electrons of 300 MeV up to 1 GeV. The maximum beam intensity was 4×10¹¹ electrons per second. The maximum duty cycle was 3%. Phase volumes for the horizontal and the vertical motions were 10^-3 rad cm and 0.75×10^-3 rad cm, respectively. The beam transport system and the radiation shielding system are also described.