My research focuses on the the late effects of radiation to patients who receive advanced forms of radiation therapy.  My recent work has also included the design, construction, and operation of proton radiation therapy centers. This covers a broad range of topics that include nozzle design, Monte Carlo simulations of treatment beams and neutron shielding, proton beam instrumentation and dosimetry, and the development of novel instruments for characterizing the behavior of the proton therapy systems. The relative scarcity of proton therapy facilities, compared to more conventional techniques, presents a unique opportunity to perform research in a promising and rapidly expanding field in radiation oncology.