On the technologies of Hα imaging spectrograph for the CHASE mission

The Hα imaging spectrograph (HIS) is the scientific payload of the first solar space mission, the Chinese Hα solar explorer (CHASE), supported by the China National Space Administration (CNSA). The CHASE/HIS achieves, for the first time in space, Hα spectroscopic observations with high spectral and temporal resolutions. Separate channels for the raster scanning mode (RSM) and continuum imaging mode (CIM) are integrated into one, and a highly integrated design is achieved through multiple folding of the optical path and ultra-light miniaturized components. The design of HIS implements a number of key technologies such as high-precision scanning of the optical field of view (FOV), high-precision integrated manufacturing inspection, a large-tolerance pre-filter window, and full-link solar radiation calibration. The HIS instrument has a pixel spectral resolution of 0.024 Å and can complete a full-Sun scanning within 46 s.