Mechanical Engineering Center’s Masterpiece: 1/4 Scale Model of the Mirror for the LiteBIRD Low-Frequency Telescope

(English translation 2024-05-17)

The Experimental Cosmology Group at the Institute for Particle and Nuclear Studies is advancing the LiteBIRD project, which aims to conduct precise observations of the Cosmic Microwave Background (CMB) radiation using a satellite. To carry out foundational experiments for this project, there has been a request to produce a 1/4 scale model of the mirror for the Low-Frequency Telescope (LFT) to be deployed on the observation satellite.
The mirror surface is non-spherical in shape, and machining was performed using a 5-axis machining center and a ball end mill (Fig. Up). We produced two types of mirrors and fixed them onto pentagonal pole shaped frames. To enhance the precision of the frames, we manufactured the frame components, assembled them, and then performed additional machining using a 5-axis machining center (Fig. Down). The size of the frame is such that it barely fits within the machining center, and there is a risk of collision with the machine depending on its orientation. Therefore, we conducted simulations in advance to confirm that machining was feasible before proceeding with the actual process.