Field scanner design for MUSTANG of the Green Bank Telescope

被引：0
作者：
MASON Brian [1 ]
机构：
[1] National Radio Astronomy Observatory,Charlottesville 22903,USA
来源：
Science China(Physics,Mechanics & Astronomy) | 2011年 / 11期
基金：
中国国家自然科学基金;
关键词：
antenna; optics; off-axis; linear astigmatism; coma; reflector scanner;
D O I：
暂无
中图分类号：
TH743 [望远镜];
学科分类号：
0803 ;
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 GHz.The detector has a field of view of 40 arcsec.To cancel out random emission change from atmosphere and other sources,requires a fast scanning reflecting system with a few arcminute ranges.In this paper,the aberrations of an off-axis system are reviewed.The condition for an optimized system is provided.In 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 view.In this paper,different scanning mirror arrangements for the GBT system are analyzed through the ray tracing analysis.These 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 mirrors.The 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 modification.The 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.
引用
收藏
页码：2091 / 2096
页数：6
相关论文
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