Design and characterization of TES bolometers and SQUID readout electronics for a balloon-borne application

TL;DR

This paper details the development and testing of TES bolometer arrays and SQUID readout electronics optimized for balloon-borne experiments, focusing on electrical and thermal characterization for low photon background conditions.

Contribution

It introduces a new array of 140 TES bolometers with optimized thermal conductance and a digital frequency domain multiplexer SQUID readout system for balloon applications.

Findings

Thermal conductance measured at 32 pW/K matches design.

Successful fabrication of 140 bolometer arrays on silicon wafers.

Effective SQUID readout electronics developed for these detectors.

Abstract

We present measurements of the electrical and thermal properties of new arrays of bolometeric detectors that were fabricated as part of a program to develop bolometers optimized for the low photon background of the EBEX balloon-borne experiment. An array consists of 140 spider-web transition edge sensor bolometers microfabricated on a 4" diameter silicon wafer. The designed average thermal conductance of bolometers on a proto-type array is 32 pW/K, and measurements are in good agreement with this value. The measurements are taken with newly developed, digital frequency domain multiplexer SQUID readout electronics.