Study of Layout Principle and Simulated Calculation for a Resonant Extraction System

Based on the general theory and related technique of 1/3 integer resonant extraction, main principle of layout for momentum-amplitude selection method is studied in detail and some simple analytic formulae are given. The design of slow extraction system for Beijing Proton Therapy Synchrotron (BPTS) is then given as an example by considering its lattice. The results are also compared with simulated calculation. Study shows that an extraction beam for BPTS with extraction efficiency above 98% and momentum spread of 0.11 % can be obtained.