High-Energy High-Resolution X-Ray Spectroscopy Eric Silver Harvard-Smithsonian Center for Astrophysics 60 Garden Street Cambridge, MA 02138 Nuclear line astrophysics provides a direct probe of the details of one of the most violent events in the universe­ a supernova explosion that expels the heavy elements in the ISM from the nuclear furnace in which they were created. Because of its production deep in the stellar core and 60 year half-life, 44Ti provides a key diagnostic of supernova explosions. By using a high resolution microcalorimeter optimized to measure the hard x-ray emission at 68 keV from the chain of 44Ti decay products, one can determine the extent and velocity distribution of the 44Ti emitting region. Details of the spectrometer and simulated results will be resented.