TES-detector based focal plane assembly key-technology developments for ATHENA and SAFARI

摘要

SRON, Netherlands Institute for Space Research, is developing a Focal Plane Assembly (FPA) for future missions requiring large-format arrays of Transition Edge Sensors (TES), read-out with Frequency Domain Multiplexing (FDM) and operating at 50 mK. The FPA is mechanically suspended from a temperature level of 1.7 K to 2 K, with an additional thermal interface at an intermediate temperature of 0.3K. The up-scaling of the amount of pixels together with the mass and volume limitations for a space instrument in general requires technology development activities in several areas. A dedicated program has been initiated for the development of a magnetic shield to provide enough attenuation over the full detector surface, to develop high density electrical wiring and interconnects and to provide a thermal insulating suspension capable to meet the mechanical requirements for launch. This with the goal of demonstrating Technology Readiness Level 4-5 (TRL) for each of these key- technologies before the end of 2015. This paper presents the status of the key-technology developments for the FPA, focusing on the following 3 subjects: Ⅰ. The development and verification of a superconducting Niobium and high permeability magnetic shield combination. Ⅱ. Development of high density superconducting interconnects, between the detector and 50 mK FDM electronics and between the 50 mK FDM electronics and the 1.7-2 K interface. Ⅲ. Mechanical and thermal characterization of a double-layered thermal insulating Kevlar suspension required to mount the 550 g 50 mK mass with a first resonance frequency larger than 300 Hz.