Magnetically Coupled Microcalorimeters

Abstract

Magnetic calorimeters have been under development for over 20 years targeting a wide variety of different applications that require very high resolution spectroscopy. They have a number of properties that distinguish them from other low temperature detectors. In this paper we review these properties and emphasize the types of application to which they are most suited. We will describe what has been learned about the best materials, geometries, and read-out amplifiers and our understanding of the measured performance and theoretical limits. While most magnetic calorimeter research has concentrated on the use of paramagnets to provide the temperature sensitivity, recently magnetically coupled microcalorimeters have been in development that utilize the diamagnetic response of superconductors. We will contrast some of the properties of the two different magnetic sensor types.