Careers in Physics Seminar Announcement Stan Johnsen Senior Scientist, Varian Medical Systems " Making X-rays for Fun or Profit " Date: Friday, April 8, 2005 416 Phy/Geo Time: 11:10 pm - Noon Abstract: The first speaker this quarter for the physics "career options" seminar will be Stan Johnsen, a physicist at Varian Medical systems. Stan writes: "I completed my PhD [at U.C. Davis] in 1975 under the tutelage of Paul Brady. My dissertation subject was measurement of a spin correlation parameter for neutron-proton scattering. The best part about that work was that it let me play with a diverse sample of lots of neat technology. "After receiving my degree I took a postdoc position with the Department of Radiotherapy at the UCD Med School. At that time they did not have the Sacramento hospital and were located in temporary buildings on campus. For two years I worked under an NCI grant to investigate the use of Crocker Lab neutron beams for radiotherapy. "When the NCI decided they did not want research facilities for clinical trials anymore and our grant was terminated, I secured a job at Varian Associates. Now known as Varian Medical Systems, the company is the world’s largest maker of equipment for treatment of cancer using radiation. I’ve been there for the last 27 years as a staff physicist, with the present title of Senior Scientist. At Varian I work in the Research and Engineering Department designing and testing electron linear accelerator systems used for radiotherapy and industrial applications."

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