一种新型挡光环的设计

传统形式的挡光环是将挡光环与遮光罩内壁垂直设置,文中设计的新型挡光环是将挡光环与遮光罩内壁倾斜设置,使入射杂光的反射光线和一部分散射光线在挡光环与遮光罩内壁所夹的空间内多次衰减无法出射,剩余的散射光线也大多逆向光学系统传播,大大消弱了到达探测器的杂散光。新型挡光环的倾角α要始终保持αβ(β为入射杂光与遮光罩内壁的夹角)的分布,才能避免一些照射到挡光环表面上的杂散光直接散射进入光学系统。文中以探测微弱星体的卡塞格林空间相机为例,在外遮光罩内部分别设置2种构型的挡光环,用T racepro软件进行建模与仿真,结果表明:采用新型挡光环的空间相机与采用传统型挡光环的空间相机相比,其探测的星等提高了4个等级。

Design of a new-style vane

The traditional vane plumbs with the inside surface of a baffle,but the new-style vane designed in this paper inclines toward the inside surface of a baffle.The reflective light from the incident parasitic light and part of the stray light is blocked in the interbedded space of the new-style vanes and inside surface of baffle to be attenuated,and most of the residual light is retro-transmitted to the optic system,so just tiny stray light is able to arrive at the detector.The inclining angle α of the new-style vane must keep the distribution that α is bigger than β which is the included angle of the incident stray light with the baffle.Only by the distribution can the inclining stray light be avoided to arrive at the optic system directly.Taking the Cassegrain space camera as an example,two types of vanes were set up respectively within external baffles of the two cameras,and then the modeling and simulation for the two structures were performed by the aid of Tracepro software.The results show that the space camera with the new vane is 4 grades higher than that with the traditional vane.