  With the high resolution of microcalorimeter detectors, previously
unresolvable gamma-ray lines are now clearly resolvable. A careful measurement
of 241Am decay with a large microcalorimeter array has yielded never before
seen or predicted gamma lines at 207.72 +/- 0.02 keV and 208.21 +/- 0.01 keV.
These have been made possible because of new microwave-multiplexing readout and
improved analysis algorithms for microcalorimeters.
