The microcalorimeter X-ray detector: A true paradigm shift in X-ray spectroscopy T. Jach, J. N. Ullom and W. T. Elam Eur. Phys. J. Special Topics, 169 (2009) 237-242 Published online: 17 March 2009 DOI: 10.1140/epjst/e2009-00998-3