Simultaneous Observation of Multiple Temprature Components of the Solar Corona with a Mirror Coronagraph

为了实现日冕多波段同时观测，同时也为将来大口径日冕观测系统的建设做准备，我们研制了一个直径为15 cm的日冕观测系统工程模型。关键技术是：1）低散射镜的制作及其质量评定方法; 2）带孔逆掩镜的制作; 3）主镜主动稳像驱动机构。2000年，采用低膨胀玻璃对离轴抛物面主镜进行了抛光。同时开发了反射镜表面粗糙度评定系统。该系统测量了激光束在不同角度的散射分量，我们在2001年对反射镜进行了评估。2003年制造了逆掩模反射镜，但我们遇到了孔边缘形状的缺陷，并研究了加工工艺的改进。设计了主镜的驱动机构，并对两个压电驱动器进行了基本性能测试，虽然作为观测系统的主镜日冕仪还没有完成，但对主要技术问题进行了前景展望。

Aiming for simultaneous observations of the solar corona in multiple wavelengths, and also for the construction of a large aperture coronagraph in future, we developed an engineering model of coronagraph with a 15-cm diameter mirror. The key technical terms are,1) fabrication of a low-scattering mirror and the method of its qualification,2) fabrication of the inverse occulting mirror with a hole,3) active driving mechanism of the primary mirror for image stabilization.The polishing of the off-axis paraboloidal primary mirror was performed in 2000 using a low-expansion glass. The system for evaluating the surface roughness of the mirror was also developed at the same time. The system measures the scattered component of laser beam in various angles, and we have performed the evaluation of the mirror in 2001.The inverse occulting mirror was fabricated in 2003, but we met a deficit in the shape of the edge of the hole and investigated the improvement of the machining process.In 2001 and 2002, the driving mechanism of the primary mirror was designed and two piezo actuators were tested for its fundamental functions.Though the mirror coronagraph was not completed as an observation system, the prospect for the major technical issues were obtained.