Detector fabrication development for the LiteBIRD satellite mission

TL;DR

LiteBIRD aims to measure cosmic microwave background polarization to understand early universe phenomena, with the US developing specialized detector units based on heritage technologies for this space mission.

Contribution

Development and fabrication of specialized detector units for LiteBIRD's focal plane, adapting existing technologies for space-based CMB measurements.

Findings

Successful fabrication of the three flight model focal plane units.

Integration of lenslet-coupled sinuous antenna pixels and horn-coupled orthomode transducer pixels.

Progress in detector technology development for space environment conditions.

Abstract

LiteBIRD is a JAXA-led strategic Large-Class satellite mission designed to measure the polarization of the cosmic microwave background and cosmic foregrounds from 34 to 448 GHz across the entire sky from L2 in the late 2020's. The primary focus of the mission is to measure primordially generated B-mode polarization at large angular scales. Beyond its primary scientific objective LiteBIRD will generate a data-set capable of probing a number of scientific inquiries including the sum of neutrino masses. The primary responsibility of United States will be to fabricate the three flight model focal plane units for the mission. The design and fabrication of these focal plane units is driven by heritage from ground based experiments and will include both lenslet-coupled sinuous antenna pixels and horn-coupled orthomode transducer pixels. The experiment will have three optical telescopes called the low frequency telescope, mid frequency telescope, and high frequency telescope each of which covers a portion of the mission's frequency range. JAXA is responsible for the construction of the low frequency telescope and the European Consortium is responsible for the mid- and high- frequency telescopes. The broad frequency coverage and low optical loading conditions, made possible by the space environment, require development and adaptation of detector technology recently deployed by other cosmic microwave background experiments. This design, fabrication, and characterization will take place at UC Berkeley, NIST, Stanford, and Colorado University, Boulder. We present the current status of the US deliverables to the LiteBIRD mission.