Design and test of a portable Gamma-Ray Burst simulator for GECAM

TL;DR

This paper presents the design and testing of a portable Gamma-Ray Burst simulator using advanced technologies to evaluate GECAM's detectors and software response before launch, demonstrating accurate simulation of various GRBs.

Contribution

The paper introduces a novel portable GRB simulator based on GCXT and DDS technologies, enabling pre-launch testing of GECAM's detectors and software response to different GRB types.

Findings

The simulator accurately reproduces programmed GRB light curves.

GECAM detectors responded consistently to simulated GRBs.

The device's time jitter is approximately 0.9 microseconds.

Abstract

The main scientific goal of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is to monitor various types of Gamma-Ray Bursts (GRB) originated from merger of binary compact stars, which could also produce gravitational wave, and collapse of massive stars. In order to study the response of GECAM Gamma-Ray Detectors (GRDs) to high-energy bursts and test the in-flight trigger and localization software of GECAM before the launch, a portable GRB simulator device is designed and implemented based on grid controlled X-ray tube (GCXT) and direct digital synthesis (DDS) technologies. The design of this GRB simulator which modulates X-ray flux powered by high voltage up to 20 kV is demonstrated, and the time jitter (FWHM) of the device is about 0.9 $\mu$s. Before the launch in December, 2020, both two GECAM satellites were irradiated by different types of GRBs (including short and long bursts in duration) generated by this GRB simulator. The light curves detected with GECAM/GRDs are consistent with the programmed input functions within statistical uncertainties, indicating the good performance of both the GRDs and the GRB simulator.