Design and simulations of a short optical baffle for the Lightweight Asymmetry and Magnetism Probe (LAMP)

摘要

The Lightweight Asymmetry and Magnetism Probe (LAMP) is a micro-satellite based mission concept for soft X-ray polarimetry at 250 eV with a large aperture but a short focal length. Due to the very low energy response of the gas pixel detector (GPD) used in LAMP, the stray light must be extremely attenuated. However, a long baffle is not favored for the micro-satellite with a limited geometry. In this paper, we propose a novel design having a short optical baffle but with high efficiency suppressing stray lights. For the optical aperture with a diameter of 700 mm used in LAMP, a short baffle of just 150 mm long can reduce the solar stray light by a factor better than 10~(-4) at the incidence angle larger than 60°, which is verified by simulations with TracePro ray-tracing software. This design meets the requirement for LAMP and the design concept should be helpful for other optical/UV/X-ray telescopes.