Software-defined Radio Readout System for the ECHo Experiment

TL;DR

This paper presents a novel software-defined radio system designed for reading out large arrays of metallic magnetic calorimeters in the ECHo experiment, pioneering microwave SQUID multiplexing in this context.

Contribution

It introduces a dedicated SDR implementation for frequency division multiplexed MMC readout, a first in the field, advancing hardware, firmware, and software development for cryogenic detector arrays.

Findings

First implementation of SDR for MMC readout in ECHo

Successful multiplexing of large MMC arrays using microwave SQUIDs

Development of specialized hardware and firmware for this application

Abstract

Metallic magnetic calorimeters (MMCs) are cryogenic detectors that offer an excellent energy resolution, a signal rise time of <100 ns, a high dynamic range and almost optimal linearity. MMCs are of high interest for many experiments. One of them, the ECHo experiment, requires the utilization of large MMC detector arrays. The readout of such MMC arrays is a challenging task, which can be tackled using software-defined radios (SDRs). Though SDR is a well-known approach in communications engineering, a dedicated implementation for frequency division multiplexed readout of MMCs is new and one of the technological key elements of the ECHo project. ECHo will be the first experiment to use microwave SQUID multiplexed MMC detectors and therefore pioneering the hardware, firmware and software development in this domain. This paper presents the detailed concepts and current status of the development.