The soft x-ray photon-counting spectroscopic imager for the sun

Abstract

We present science and development activities of the soft X-ray photon-counting spectroscopic imager for the solar corona that we conceive as a possible scientific payload for the Japanese Solar-C mission. The imager employs a grazing-incidence sector mirror of Wolter-I type with which images of the corona are to be taken in a wide temperature range (1 MK to beyond 10 MK) with the highest-ever angular resolution (0.5"/pixel for a focal length of 4 m) as an Xray telescope for the Sun. Moreover, by employing a back-thinned CMOS image sensor as the focal-plane device, we attempmt to implement photon-counting capability with which imaging-spectroscopy of the X-ray corona will be performed for the first time, in the energy range from ~0.5 keV up to 10 keV. The imaging-spectroscopic observations will provide totally-new information on mechanism(s) for magnetic reconnection, generation of supra-thermal electrons in the reconnecting magnetic structure during flares, and for the generation of hot coronal plasmas (heated beyond a few MK) which may be responsible for the formation of the hot cores of solar active regions.