This is an SBIR Phase I award for the investigation of the photoconductive response of diamond films and asses their performance as ultra high voltage/high current power switches for switching applications in linear accelerators. The proposed research will lead to the commercialization of ultrafast switching technology for high voltage/high power applications in compact, high gradient linear accelerators for medical treatment and diagnosis, x-ray inspection, e-beam welding and to extending the technology to larger applications such as injection machines for synchrotrons and free electron lasers.