Design and on-orbit operation of the Soft X-ray Spectrometer ADR on the Hitomi Observatory.

The Soft X-ray Spectrometer (SXS) instrument that flew on the Astro-H observatory was designed to perform imaging and spectroscopy of x-rays in the energy range of 0.2 to 13 keV with a resolution requirement of 7 eV or better. This was accomplished using a 6x6 array of x-ray microcalorimeters cooled to an operating temperature of 50 mK by an adiabatic demagnetization refrigerator (ADR).

Operating Modes and Cooling Capabilities of the 3-Stage ADR Developed for the Soft-X-ray Spectrometer Instrument on Astro-H.

A 3-stage adiabatic demagnetization refrigerator (ADR)[1] is used on the Soft X-ray Spectrometer instrument[2] on Astro-H[3] to cool a 6×6 array of x-ray microcalorimeters to 50 mK. The ADR is supported by a cryogenic system[4] consisting of a superfluid helium tank, a 4.5 K Joule-Thomson (JT) cryocooler, and additional 2-stage Stirling cryocoolers that pre-cool the JT cooler and cool radiation shields within the cryostat.