LiteBIRD payload module

The payload module (PLM) of the next-generation CMB satellite LiteBIRD features three telescopes: a crossed-Dragone reflective Low-Frequency Telescope (LFT), and on-axis refractive Mid- and High-Frequency Telescopes (MFT and HFT), spanning 15 unique frequency bands from 34 to 448 GHz. <br/><br/> Central to the PLM are Transition Edge Sensor (TES) bolometers, maintained at a bath temperature of ~110 mK. They are coupled to the sky with silicon lenslets with metamaterial anti-reflection surfaces (LFT and MFT) and platelet-based horns (HFT). The cryogenic and room-temperature electronics translate the tiny thermal signals from TES bolometers into digital data at 18 GB/day. The PLM thermal management utilizes passively and actively cooled V-grooves and a series of coolers including a space-grade adiabatic demagnetization refrigerator. Polarization is modulated by continuously rotating achromatic half-wave plates held at around 10 K. <br/><br/> This design focuses on reducing systematic errors and enhancing stability. Combining systematic uncertainties, a statistical uncertainty of 2.2μK-arcmin in polarization, and margin, we will achieve a δr=0.001 precision on the tensor-to-scalar ratio r.