Ion-Implanted Silicon X-Ray Calorimeters: Present and Future

We now have about 25 years of experience with X-ray calorimeters based on doped semiconductor thermometers. Ion-implanted Si arrays have been used in astrophysics and laboratory atomic physics. The device properties and characteristics are sufficiently well understood to allow optimized designs for a wide variety of applications over the 0.1–100 keV range. With new absorber materials, approaches for absorber attachment and compact, low thermal conductance JFET arrays, it should be possible to advance this technology from the 36 pixel arrays of today to arrays that are about an order of magnitude larger, and with significantly improved energy resolution. These would enable new capabilities on instruments being considered now for missions that may fly in about five years.