I do observational research on clusters of galaxies and I develop instrumentation, mainly for high-energy astrophysics. Recently my observational work has focused on the astrophysics of a new collection–clusters detected in a Sunyaev-Zeldovich survey performed by the South Pole Telescope, and on hitherto unexplored regions at the outskirts of clusters. I am also working with groups at MKI and at MIT Lincoln Laboratory on next-generation active pixel X-ray imaging detectors.