The SAFARI Detector System

TL;DR

The paper presents the design and overview of the SAFARI detector system, utilizing superconducting TES detectors with FDM readout for the SPICA space observatory to achieve high sensitivity in infrared observations.

Contribution

It introduces a novel detector system design for SAFARI, combining superconducting TES detectors with frequency domain multiplexing and SQUID preamplifiers.

Findings

Achieves dark NEP of ≤2×10^{-19} W/√Hz for detectors.

Supports approximately 3500 detectors with FDM readout.

Uses two-stage SQUID preamplifiers for efficient detector readout.

Abstract

We give an overview of the baseline detector system for SAFARI, the prime focal-plane instrument on board the proposed space infrared observatory, SPICA. SAFARI's detectors are based on superconducting Transition Edge Sensors (TES) to provide the extreme sensitivity (dark NEP$\le2\times10^{-19}\rm\ W/\sqrt Hz$) needed to take advantage of SPICA's cold (<8 K) telescope. In order to read out the total of ~3500 detectors we use frequency domain multiplexing (FDM) with baseband feedback. In each multiplexing channel, a two-stage SQUID preamplifier reads out 160 detectors. We describe the detector system and discuss some of the considerations that informed its design.