X-ray beam experiment for the Hard X-ray Imager onboard ASO-S

Abstract

The Hard X-ray Imager (HXI) is one of the scientific payloads onboard the Advanced Space-based Solar Observatory. As a telescope using Fourier space modulation, it contains fine sub-collimators to reach high angular resolution. The X-ray resolution of HXI needs to be verified on the ground before its launch. Therefore, an X-ray beam experiment was performed to evaluate the modulation capabilities of each sub-collimator in HXI.The X-ray beam facility for this experiment consisted of an X-ray machine with a 0.4 mm-diameter spot, a 26-meter beam tube with an adjustable diaphragm at the end to control the parallelism of the beam, and an experimental platform that could translate and horizontally rotate the instrument on it with high precision. A strategy for measuring these sub-collimators was then developed theoretically. Additionally, the stability of the instrument and the environment were monitored throughout the experiment.The results of the successful experiment are presented in this paper. The relevant parameters fitted from the measured modulation functions agree well with theoretical predictions. This proves the resolving ability of the HXI meets the requirements. The research also illustrates some side effects due to different incident energies and strengtheners.