Session chairperson: Dan M. Goebel
Summary authors: David Whaley and Monica Blank
The first three plenary sessions of the conference described three important applications of vacuum electron devices – space observational instruments and downlinks, digital communications, and high power heating for particle accelerators and thermonuclear fusion systems. In the first plenary session, Dr. Wayne Harvey of the Jet Propulsion Laboratory discussed the history and future requirements of downlink TWTAs for missions such as the Mars Reconnaissance Orbiter. As well, observational systems for applications such as cloud profiling radar, oceanic altimeters, and atmospheric ozone detection were described requiring high power, high frequency sources available only through vacuum electronics technology. Dr. Harvey predicted an increased use of vacuum devices in NASA space systems as the interest and stringent source requirements for such applications grow in future years. The second plenary session was given by Dr. Dan Goebel of Boeing Electron Dynamic Devices on requirements for future high data rate communication applications. Higher-order modulation schemes such as 8PSK and 64QAM were described as well as TWT development efforts needed to realize amplifier performance required of systems utilizing these techniques. Streaming digital video from space missions, high-definition Internet television, and digital satellite radio are a few of the myriad of applications which will benefit from the development of this technology. The third speaker, Dr. Manfred Thumm of Forschungszentrum Karlsruhe described current state-of-the-art high-power vacuum devices used for both particle accelerators and fusion systems in Europe. Particle accelerators use klystrons operating up to 65 MW pulsed at S-Band frequencies and up to 1MW CW at 500 MHz. In addition, fusion systems using vacuum devices for ion cyclotron, electron cyclotron, and lower hybrid resonant heating exist throughout Europe. These RF vacuum devices, including gyrotrons, klystrons and tetrodes, generate RF power at frequencies between 20 MHz and 170 GHz at power levels of 1 MW CW to 100 MW in microsecond pulses.
The fourth plenary talk, presented by Dr. James Dayton, Jr. from GENVAC Aerospace in Cleveland, Ohio, described the results of an informal survey circulated among young professionals in the vacuum electronics field designed to gain insight into the issues surrounding the training of the next generation in our field. By and large, professionals in the field are drawn by the quality people in the vacuum electronics industry and by the challenge of a science that covers so many disciplines. Next, Dr. Kyu-Suk Chang from Samsumg Electronics in Suwon City, Korea presented a history of the development and mass production of magnetrons for microwave ovens. No doubt many in the audience were envious of Samsung's ability to produce sophisticated magnetrons at a per-item item cost of $7. Dr. Bruce Miller of SureBeam Corporation in San Diego, California then described the technology of food irradiation using electron accelerators. He focused on key issues such as how the volume and type of food that must be processed dictate the energy of the radiation and the type of device necessary to adequately irradiate the food. He emphasized the large amount of research which has concluded that food irradiation is not only safe, but has significantly benefited public health. In the final plenary talk, presented by Dr. John Booske from the University of Wisconsin in Madison, Wisconsin, the new opportunities for microfabricated vacuum electronic devices were presented. The new opportunities he mentioned were primarily focused on precise, reliable, high-yield fabrication techniques. He mentioned the impressive progress on field emitter arrays and the growing research in microfabricated vacuum electronic devices, or "mVED's." Research is underway to develop high power W-band klystron amplifiers using LIGA, which involves a combination of xray lithography and electrodeposition.