  The Robust Conjugate Direction Search (RCDS) method is used to optimize the
collimation system for Rapid Cycling Synchrotron (RCS) of the Chinese
Spallation Neutron Source (CSNS). The parameters of secondary collimators are
optimized for a better performance of the collimation system. To improve the
efficiency of the optimization, the Objective Ring Beam Injection and Tracking
(ORBIT) parallel module combined with MATLAB parallel computing is used, which
can run multiple ORBIT instances simultaneously. This study presents a way to
figure out an optimal parameter combination of the secondary collimators for a
machine model in preparation for CSNS/RCS commissioning.
