In-flight performance of the MXT Camera

TL;DR

This paper evaluates the in-flight performance of the MXT Camera on the SVOM mission, focusing on calibration, tuning, and initial results in X-ray imaging and spectroscopy of gamma-ray burst afterglows.

Contribution

It presents the design, calibration, and initial in-flight performance analysis of the MXT Camera, including tuning procedures and spectral response evolution.

Findings

Camera design validated by ground testing

Successful in-flight calibration and tuning

Initial spectral response performance reported

Abstract

On-board the SVOM mission, the Microchannel X-ray Telescope observes the soft X-ray band of the gamma-ray bursts afterglows. The so-called lobster-eye optics focuses X-rays to the camera subsystem that performs imaging and spectroscopy of a region of the sky 58x58 arcmin2 wide centered on the burst detected by the ECLAIRs instrument. The recorded photon positions are used by the on-board scientific software to rapidly localize the source, whereas spectral information is used on ground to model the properties of the gamma-ray bursts. The first months in orbit were intensively used to tune the parameter settings of the detector and the calibration method to provide high availability of the camera and accurate spectroscopy to the users. The paper presents the design of the camera validated by on-ground testing, the tuning phase in flight and the performance of the camera at the beginning of the mission. Perspectives are given concerning the evolution of the spectral response during the mission.