A Tiltable Single-Shot Miniature Dilution Refrigerator for Astrophysical Applications

TL;DR

This paper introduces a compact, tilt-capable dilution refrigerator designed for astrophysical telescope receivers, achieving ultra-low temperatures around 100 mK with stable operation even at significant tilt angles.

Contribution

The authors present a novel cryogen-free dilution refrigerator with a geometry that allows tilting up to 45 degrees, suitable for astronomical applications requiring receiver rotation.

Findings

Achieves 2 microW cooling power at 87 mK

Operates reliably with tilt angles over 45 degrees

Compatible with existing telescope cryogenic systems

Abstract

We present a 3He / 4He dilution refrigerator designed for cooling astronomical mm-wave telescope receivers to around 100 mK. Used in combination with a Gifford-McMahon closed-cycle refrigerator, 4He and 3He sorption-pumped refrigerators, our cryogen-free system is capable of achieving 2 microW cooling power at 87 mK. A receiver attached directly to the telescope optics is required to rotate with respect to the downward direction. This scenario, of variable tilt, has proved difficult for typical dilution refrigerators, but our design has a geometry chosen to allow tilt to 45 degrees and beyond.