Assembly development for the Simons Observatory focal plane readout module

TL;DR

This paper discusses the development and validation of multiplexing modules for the Simons Observatory's focal plane readout, crucial for handling thousands of detectors in CMB observations.

Contribution

It introduces the assembly process and validation methods for multiplexing modules used in the SO focal plane, enhancing detector integration.

Findings

Successful assembly of multiplexing modules meeting performance specs

Validation procedures ensure reliability of the readout modules

Facilitates large-scale deployment of TES detectors in CMB experiments

Abstract

The Simons Observatory (SO) is a suite of instruments sensitive to temperature and polarization of the cosmic microwave background (CMB) to be located at Cerro Toco in the Atacama Desert in Chile. Five telescopes, one large aperture telescope and four small aperture telescopes, will host roughly 70,000 highly multiplexed transition edge sensor (TES) detectors operated at 100 mK. Each SO focal plane module (UFM) couples 1,764 TESes to microwave resonators in a microwave multiplexing (uMux) readout circuit. Before detector integration, the 100 mK uMux components are packaged into multiplexing modules (UMMs), which are independently validated to ensure they meet SO performance specifications. Here we present the assembly developments of these UMM readout packages for mid frequency (90/150 GHz) and ultra high frequency (220/280 GHz) UFMs.