Abstract:
DoE has a long-term program to support high gradient accelerators using “warm” (i.e., non-superconducting) rf in support of a future TeV electron-positron linear collider.  As part of this program, NRL developed a 25 MW, 11.4 GHz magnicon amplifier, a unique scanning electron beam microwave tube, in collaboration with scientists from Omega-P, Inc.  The magnicon is now the heart of the NRL Magnicon Facility, a laboratory that is dedicated to collaborative research on advanced accelerating structures and high power microwave components.  This seminar will present a brief discussion of the operating principles of the magnicon, and will focus on two experimental programs that are under way in the Magnicon Facility.  The first is a study of dielectric-loaded accelerating structures, a possible alternative to conventional metal disk-loaded structures for improved high-gradient acceleration.  This study focuses on multipactor and breakdown phenomena in these structures.  The second is a study of active microwave pulse compressors using either plasma or electron beam switching.  Microwave pulse compressors are used to provide the high peak power pulses needed to drive high gradient accelerating structures, and active pulse compressors offer higher compression ratios and improved efficiencies compared to the passive compressors that are currently in use. 

Brief biography:
Steven H. Gold is the Senior Scientist for Radiation Generation Physics in the Beam Physics Branch at the Naval Research Laboratory, where he has worked since obtaining his Ph.D. in physics from the University of Maryland in 1978.  His research interests include high-power microwave generation, fast-wave microwave devices, and applications of high-power microwave sources to accelerators and industrial processes.  He presently directs a program to study accelerator-related microwave technologies, including active microwave pulse compressors and dielectric-loaded accelerators and, most recently, is carrying out a study of thermionic injectors for high-current electron linacs.  He has published more than 60 journal articles and 100 proceedings papers and holds 5 US Patents and 2 Statutory Invention Registrations.  He is currently a member of the IEEE Fellow Committee and the IEEE Nuclear and Plasma Sciences Society Administrative Committee, Secretary of the NPSS Plasma Science and Applications Committee, and Technical Program Chair of the 2011 IEEE International Conference on Plasma Science, and previously served for twenty years as an Associate Editor of the IEEE Transactions on Plasma Science.  He is a Fellow of the IEEE and the American Physical Society, and received the 2008 NPSS Richard F. Shea Distinguished Member Award “for outstanding contributions to the IEEE Nuclear and Plasma Sciences Society and its Plasma Science and Applications Technical Committee.”