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Princeton Plasma Physics Laboratory Honors Three Researchers

Plainsboro, New Jersey — The U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) honored three fusion energy researchers — Manfred Bitter, Robert Ellis, and Ken Hill — for their scientific accomplishments during an awards ceremony on March 8 at the laboratory. Physicists Bitter and Hill received the Kaul Prize for Excellence in Plasma Physics Research and Technology Development. Ellis, an engineer, received the PPPL Distinguished Engineering Fellow award.

The laboratory cited the Kaul Prize recipients for their pioneering work in advancing the field of X-ray spectroscopy and technology for plasma diagnostics, with additional potential applications to other areas. The scientists developed a special X-ray imaging crystal spectrometer — an instrument that measures profiles with high spatial resolution of the temperatures and flow velocities of hot plasmas — to gain a better understanding of fusion plasmas. Plasma is a hot gas that makes up the stars and is used as the fuel to produce fusion energy.

The Engineering Fellow was recognized for his outstanding innovation and engineering accomplishments in the development of wave-based heating systems and diagnostic devices for fusion research, and for his leadership in many areas of fusion engineering.

Kaul Prize Recipients


Manfred Bitter is a principal research physicist in the Plasma Diagnostics Division at PPPL. He was educated in Germany, where he received a diploma and a Ph.D., both in physics, from the Universities in Munich and Aachen in 1965 and 1968. Prior to joining PPPL in 1977, he was a staff member of the European Space Research Institute in Frascati, Italy, from 1969 to 1973 and a visiting scientist at the Centre des Recherches en Physique des Plasmas in Lausanne, Switzerland, from 1973 to 1977. At PPPL, he co-developed with PPPL physicist S. von Goeler (now retired) the high-resolution X-ray spectroscopy of hot tokamak plasmas for measurements of the plasma ion temperature and plasma flow velocities, using spectral lines of highly charged ions from elements, such as argon, iron, nickel, and krypton.

More recently, Bitter invented, and he and Hill developed the novel high-resolution X-ray imaging crystal spectrometer. This new type of spectrometer was installed on many tokamaks and stellarators — types of fusion devices — in the U.S., China, Korea, and Japan, and its instrumental concept has also been adopted for measurements on ITER, an international fusion experiment being built in the south of France. Bitter was named a Fellow of the American Physical Society in 1987 and was one of the recipients of the Alexander von Humboldt Physics Prize in 1996, which allowed him to spend one year of research at the Forschungszentrum Jülich in Germany. He lives in Princeton, N.J.


Kenneth Hill is a principal research physicist working in the Diagnostics Division at PPPL. He received a Ph.D. in atomic physics from the University of North Carolina at Chapel Hill in 1974. Prior to joining PPPL in 1978, he worked in ion-atom collision physics at the U.S. Naval Research Laboratory, and in spectroscopic plasma diagnostics at the Oak Ridge National Laboratory. He is the author or coauthor of more than 320 publications in atomic and plasma physics, and has spent significant time collaborating with and working at research institutes in Japan, Germany, China, and Korea. His focus at PPPL has been on the development of plasma X-ray diagnostics and applying these measurements to study energy transport and impurity behavior. Hill is a member of the American Physical Society. He lives in Plainsboro Township, N.J.

“Dr. Bitter’s and Dr. Hill’s award recognizes their development of novel imaging techniques for X-ray-based diagnostics. These methods are internationally recognized for their ability to robustly measure plasma temperature and flow profiles, independent of heating methods. The techniques developed by Manfred and Ken have been adopted on many large fusion experiments and have been selected for use on ITER. Due to the unique capabilities of these techniques, they are also being extended to other fields where X-ray diagnostics and optics are important. Manfred and Ken are richly deserving of the Kaul award,” said Michael Zarnstorff, deputy director for research at PPPL.

Princeton University awards the Kaul Prize to recognize a recent outstanding technical achievement in plasma physics or technology development by a full-time, regular employee of PPPL. It includes a cash award of $6,000 for each recipient. Former PPPL Director Ronald C. Davidson endowed the Kaul Prize by giving to Princeton University a portion of the gift he received as the 1993 recipient of the Award for Excellence in Science, Education, and Physics from the Kaul Foundation.

PPPL Distinguished Engineering Fellow


Robert Ellis is a principal engineer specializing in the design of radio-frequency equipment and diagnostic systems for fusion energy experiments. Ellis received a bachelor’s degree in engineering from Princeton University in 1979, with graduate study at the same institution, before joining the staff at PPPL in 1981. He received a master’s degree in mechanical engineering from the New Jersey Institute of Technology in 1998. He has worked primarily on domestic and international collaborations in fusion energy, designing experimental equipment for laboratories in the United States, England, and Korea. He worked on the JT-60 fusion experiment in Japan as part of a U.S.-Japan exchange program. Ellis lives in Ewing, N.J.

“Bob is a versatile engineer well known throughout the national and international fusion community. His development of electromagnetic wave launchers for tokamaks in the U.S. and South Korea, and of techniques to meet National Compact Stellarator Experiment dimensional requirements, among other contributions, has distinguished his engineering talents. Recognition as a PPPL Distinguished Engineering Fellow is well deserved,” said Mike Williams, PPPL associate laboratory director for engineering and infrastructure.

The Distinguished Research and Engineering Fellow Program, funded by the U.S. Department of Energy, was created to recognize members of the laboratory’s research staff, as well as engineering and scientific staff, for their accomplishments. Fellows receive one-time gifts of $5,000 and qualify for priority in regard to their research and engineering programs.

Princeton Plasma Physics Laboratory, funded by the U.S. Department of Energy and managed by Princeton University, advances the coupled fields of fusion energy and plasma physics. Fusion is the process that powers the sun and the stars. In the interior of stars, matter is converted into energy by the fusion, or joining, of the nuclei of light atoms to form heavier elements. At PPPL, physicists use a magnetic field to confine plasma. Scientists hope eventually to use fusion energy for the generation of electricity. http://www.pppl.gov/

U.S. Department of Energy
Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.

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