Ph. D. in Physics in 1986, in the field of particle accelerators, has published over 50 papers on a variety of physics topics. He has designed and built several complete particle accelerator systems over the years, including a 2.5 MeV, ampere intensity electron beam system and a 10 MeV He-3 ion beam system for PET isotope production. He served as a leading designer of the cancelled Superconducting Super Collider, doing longitudinal dynamics designs for that lab. Dr. Larson has written computer applications for space charge inclusive transverse ion optics and a separate code for longitudinal particle optics. Dr. Larson's computer codes have been used at laboratories around the world. Dr. Larson is presently leading the design of particle accelerators for use in medical therapy.