DIXE: A High-Resolution X-ray Spectroscopic Survey Mission

DIfuse X-ray Explorer (DIXE) is proposed for the China Space Station (CSS). It employs a 10x10 TES microcalorimeter array, which is mechanically collimated to a field of view of 10° (FWHM) and offers an energy resolution of 6 eV over the energy range of 0.1-10 keV. The microcalorimeter array is cooled to below 100 mK with a combination of cryocoolers and a two-stage adiabatic demagnetization refrigerator. DIXE is designed to operate in scanning survey mode and is expected to provide X-ray data of high spectral resolution over much of the sky (with coverage holes around the poles of the CSS orbit). The primary scientific objective of DIXE is to gain insights into the origins of large structures of hot gas in the Milky Way (including the Local Bubble, eROSITA Bubble, and halo). In this work, the design of DIXE is described.