Portable Solid Nitrogen Cooling System for High Transition Temperature Superconductive Electronics

Abstract

In this article, we present a miniature solid nitrogen cooling system designed for high-transition temperature (high-T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> ) superconductor Josephson devices operating in the temperature range of 40-55 K. The system utilizes a small fiberglass Dewar and an external pump to solidify nitrogen in thermal contact with a circuit board insert. Our cooling tests of two different Dewars with 100 mL and 200 mL capacity reveal that the systems can hold at their lowest base temperature of 42 K for 1.2 hours and 45 K for 4.7 hours for the 100 mL and 200 mL Dewars, respectively. This can provide a low power, low weight cooling solution for ultra-portable superconductive electronics and other cryogenic sensors.