太阳Hα空间光谱仪光学设计

Optical design of solar Hα space telescope

太阳Hα是广泛用来观测耀斑及暗条等众多太阳活动现象的一条重要谱线,太阳Hα空间光谱仪的研制是我国研究太阳光谱的迫切需要.设计的太阳Hα空间光谱仪由前置光学系统(观星子系统)、Czerny-Turner结构型光谱仪、推扫运动系统和入射窗口组成.太阳Hα空间望远镜的焦距拟定为1820 mm,口径180 mm.经分析,采用像元尺寸4.6μm的探测器可以实现0.523″的像元分辨率,并覆盖40′×40′的矩形视场.根据指标要求,为实现Hα波段中心波长±1?,设计谱线半宽(FWHM)0.15?的对日成像,设计工作波段为6462.81–6662.81A.

Solar Hα is an important spectral line widely used to observe many solar phenomena, such as flares and filaments. The development of solar Hα space spectrometer is an urgent need in China. The solar Hα space spectrometer is composed of a front optical system(star-watching subsystem), a Czerny-Turner structure spectrometer, a scanning mirror system and an incident window. The focal length of the solar Hα space telescope is designed to be 1820 mm and the aperture of the solar Hα space telescope is 180 mm. The analysis shows that the pixel resolution of 0.523″ can be achieved by using the detector with the pixel size of 4.6 μm, and the rectangular field of view of 40′×40′ can be covered. According to the requirement of the target, in order to realize the central wavelength(+1) in the Hα band, a half-width spectrum(FWHM)of 0.15 is designed, and the working band is 6462.81–6662.81 A.