Pictured: The Microwave Cavity: key component of a Plasma-Loaded Backward Wave
|The Institute for Plasma Research is a
multidisciplinary center of excellence for basic and applied research in charged particle
beams, plasmas, high power microwave generation, millimeter-wave electronics, advanced
high energy particle accelerators, ion beam microfabrication, nonlinear dynamics (chaos)
IPRs staff includes 28 faculty members from five academic departments
(many of them from EE), plus 30 research faculty and three dozen graduate students.
Much of the centers research involves plasma, an ionized gas that makes up some 98%
of the visible matter in the universe. Plasma plays an important role in Controlled
Thermonuclear Fusion (CTF), both in magnetically confined plasma and in plasma created and
compressed by lasers or heavy ion beams. CTF reactors could provide a lasting solution to
the worlds energy problem, so this area of study is one focus for research at IPR.
IPR researchers are also studying advanced technology for charged particle accelerators
to be used in high energy physics research. One example is the gyroklystron, a high-power
microwave amplifier, large numbers of which might be used to drive electron and positron
accelerators to TeV energy levels. The gyroklystron is a type of microwave and
millimeter-wave power tube that emits coherent radiation at the electron cyclotron
frequency. It can be used advantageously for radar and communications in addition to
Microwave and millimeter-wave technologies are a major general area of study at IPR.
Microwaves are useful in both radar and communications, especially because they can
penetrate fog, dust, and smoke, while optical and infrared waves cannot. Millimeter-waves
share this property to some degree, and their shorter wavelength enables greatly reduced
equipment and antenna size. Both microwave and millimeter-wave systems allow for large
bandwidths, making them attractive for communication applications.
Other areas of research at IPR include nonlinear dynamics, advanced materials
processing technology, and microstructure fabrication with ion beams. Research is
sponsored primarily by the Department of Energy, the Department of Defense, the National
Science Foundation, and the National Aeronautics and Space Administration.
Electrical engineering faculty conducting research at IPR include: IPR Director Prof.
Victor Granatstein, Prof. John Melngailis, Prof. Wesley Lawson, Prof. Jon Orloff, Prof.
Martin Reiser, Prof. William Destler, Prof. Edward Ott, Prof. Thomas Antonsen, and Prof.
Romel Gomez. Some of their projects are briefly described below.
High Brightness H Ion Beams, Beam Transport and Focusing
Ion beams are used in lithography, for producing integrated circuits with a dense
packaging of components. This project involves the study of intense, high brightness
H beams. Current research is directed toward: (a) the application of H beams
for ion projection lithography, and (b) the study of ion beam transport and focusing using
electrostatic quadrupole lenses.
High Power Gyroklystron Amplifiers for Driving Electron-Positron Supercolliders
Research within this project seeks to increase the power of current Gyroklystron
amplifiers by a factor of ten. Gyroklystron amplifiers have inherent advantages over
conventional klystrons in terms of producing higher power at shorter wavelengths.
Analysis, numerical simulation, and laboratory experiments are all employed in attempting
to maximize amplifier efficiency and minimize spurious phase fluctuations. Variations in
the amplifier circuit configuration (e.g., Gyrotwystrons) are also under consideration.
This project involves the development of novel high-efficiency, harmonic gyrotron sources.
One such device, called the axially-modulated, cusp-injected, large-orbit gyrotron, is a
hybrid microwave amplifier that uses the axial bunching mechanism of the klystron
amplifier on an annular, linearly-streaming beam to prebunch a large-orbit gyrotron.
Harmonic Multiplying Gyrotron Phase-Locked Oscillators and Amplifiers
This project involves both theoretical and experimental studies of various configurations
of multistage gyrodevices. These high power sources of millimeter-wave, phase-controlled
radiation have applications which include imaging radar, electronic warfare and
Theory and Modeling of Advanced High Energy Microwave Sources
This project involves the theoretical description, analysis and modeling of both slow-wave
and fast-wave microwave sourcesincluding gyroklystron, gyrotwystron, harmonic
gyrotron amplifier, backward wave oscillator, plasma/microwave electronics, and free
electron lasers. One problem in the design of high-power, high frequency radiation sources
is ensuring thet they operate in the desired mode, especially in high power devices
because, typically at the optimum operating point, a large number of modes can be excited.
Maryland researchers want to maximize the efficiency of the device while ensuring single
Plasma Microwave Electronics
This project involves research aimed at improving the understanding of the interaction
between the electron beam, electromagnetic waves, and background plasma. Specifically,
researchers are invesigating plasma-loaded microwave oscillators and amplifiers, with the
goal of designing advanced microwave sources of higher peak powers (greater than 109
Watt), higher efficiency, and improved bandwidth.
Microwave Processing of Materials
This program involves the research and development of new ways of processing materials
(such as ceramics and polymers) using microwave radiation. Microwave processing has
advantages over conventional heating in its significant reductions in processing time,
control over thermal gradients, novel microstructure properties, selective heating in
composites, and the synthesis of new materials.
For more information about the Institute for Plasma Research, please contact IPR
Director Prof. Thomas Antonsen, at (301) 405-4956.