The present and future of microcalorimeter X-ray detectors for fundamental X-ray parameters

Microcalorimeter x-ray detectors offer the specific advantage of being high -resolution energy -dispersive detectors. Furthermore, they can be designed to cover almost any energy range, from soft x-rays to gamma rays. Many of the current energy values of L, M, and N x-ray lines in the soft x-ray range (below 1.2 keV) have not been established through a chain of calibration. Based on our experience, we propose here a method of measuring the energies of these lines that should establish peak positions to a few tenths of an electron volt. It would involve the calibration of a microcalorimeter detector with diagram line energy values determined by a grating x-ray spectrometer calibrated by a plane grating monochromator using synchrotron radiation. We present L -line spectra from Cu, Co, and Ni obtained with a microcalorimeter detector to demonstrate the feasibility of obtaining high -resolution spectra in the energy range below 1 keV.