摘要：MUSTANG (Multiplex SQUID TES Array at Ninety GHz) is a bolometer camera for the Green Bank Telescope (GBT) working at a frequency of 90 *** detector has a field of view of 40 *** cancel out random emission change from atmosphere and other sources,requires a fast scanning reflecting system with a few arcminute *** this paper,the aberrations of an off-axis system are *** condition for an optimized system is *** an optimized system,as additional image transfer mirrors are introduced,new aberrations of the off-axis system may be reintroduced,resulting in a limited field of *** this paper,different scanning mirror arrangements for the GBT system are analyzed through the ray tracing *** include using the subreflector as the scanning mirror,chopping a flat mirror and transferring image with an ellipse mirror,and chopping a flat mirror and transferring image with a pair of face-to-face paraboloid *** system analysis shows that chopping a flat mirror and using a well aligned pair of paraboloids can generate the required field of view for the MUSTANG detector system,while other systems all suffer from larger off-axis aberrations added by the system *** spot diagrams of the well aligned pair of paraboloids produced are only about one Airy disk size within a scanning angle of about 3 arcmin.