Burt Fried was an internationally renowned theoretical physicist and pioneering computer researcher in the aerospace industry before becoming a professor at UCLA. He retired from UCLA in 1991.

Fried made many fundamental contributions to the study of the behavior of plasmas. One of his more influential works was a book which presented an analysis of a mathematical function widely known as the "plasma dispersion function" or simply the Z-function. This function describes the kinetic linear response of a Maxwellian plasma including the Landau damping process. It is used widely to study phenomena ranging from space plasmas to the design of fusion reactors. This treatise, co-authored in 1961 with S. Conte, continues to be extensively quoted by modern researchers.

Much of his work was focused on the theoretical understanding of linear and nonlinear waves in plasmas. One of his seminal discoveries is now called the Fried-Weibel instability which occurs in unmagnetized plasmas having anisotropic temperatures and are therefore out of thermal equilibrium. The available free energy triggers the spontaneous growth of magnetic fluctuations that in essence cause a mixing of the two initially uncoupled directions and brings about the relaxation of the configuration. The phenomenon is of great significance to space plasma studies and to the propagation of dense particle beams. Another topic to which Fried contributed extensively was the behavior of ion acoustic waves in hot plasmas. In particular his collaboration with R. Gould led to the delineation of the threshold conditions required to trigger the growth of ion oscillations by a population of drifting electrons. This is a generic situation encountered when large currents flow in plasmas.

Fried was an outspoken champion of magnetic fusion as the ultimate energy source for mankind. He participated and chaired numerous national panels and committees that chartered the early development of this field, which is presently poised to undergo major development. Fried was Chair of the Division of Plasma Physics of the American Physical Society in 1979. He was also the founding editor of the journal "Comments on Plasma and Controlled Fusion" and oversaw its publication for nearly two decades.

Fried's activities and influence crossed international boundaries and over the years he developed close relationships with scientists in Japan and in the former Soviet Union. Warmly known by colleagues abroad as "Burt," Fried's many travels and contacts helped bring together plasma scientists during the difficult years of the cold war. He was one of the first American plasma physicists to travel to Japan, and was instrumental in bringing young Japanese scientists to this country. His efforts resulted in the development of close ties between young Japanese scientists and U.S. plasma researchers that have evolved into major long-term collaborations. He participated by co-authoring papers with his many international colleagues.

Fried was born in 1926 and grew up in Chicago. During World War II he enlisted in the Navy and was trained as a radio technician, a title that he often repeated with pride to his distinguished academic colleagues. He went on to complete a Ph. D. in 1952 at the University of Chicago under the guidance of Prof. Gregor Wentzel, a pioneering theoretical physicist. As a graduate student, Fried concentrated on the theoretical description of the electron-neutron interaction and its relation to pseudo-scalar meson theory.

Fried briefly held a postdoctoral appointment at the Lawrence laboratory in Berkeley, where he went originally with the intention of working with Robert Oppenheimer. In 1954 Fried joined the fledging company now known as TRW. He was one of the early young Ph. D.s hired by Simon Ramo at what Fried always referred to as the "barber shop," the original headquarters for this company. While at TRW, Fried became the director of its computer division. In this capacity he teamed with Glen Culler to develop a pioneering on-line computational platform, known as the Culler-Fried system, which predated the modern-day PC-based computational software used extensively by scientists and engineers. To this day, some senior researchers still have versions of the system and argue that this is the best tool to do mathematical physics calculations.

After a successful career at TRW during which he published various papers on the general formulation of powered flight optimization problems, in 1965 Fried joined the faculty of the Department of Physics at UCLA as a full professor. While at UCLA, Fried combined his experience as an industrial manager with his innate ability to identify technical talent to assemble one of the world's leading plasma research groups.

Fried's efforts brought distinction to UCLA in this field and made UCLA a center for the development and training of plasma scientists in the United States. For nearly thirty years, Fried nourished the development of this talent, and watched with satisfaction while his protegees grew into accomplished leaders of the field. Many of his former students and postdocs presently lead major research groups at various institutions.

Fried was a most exacting but fair individual who always allowed true talent to shine and readily passed along credits to those who deserved them. Over time, his reputation for high standards made many a seminar speaker tremble in anticipation of his incisive scrutiny. However, for those who seriously paid attention to his deep technical remarks, he was warm, fair and encouraging mentor, a characteristic that made him beloved of his students.

Fried was an individual with broad interests who read widely and had a great appreciation for music. Fried's hobby was magic, a craft that he practiced in his spare time and displayed to close friends. Fried is survived by his wife, Sally, and their sons Joel, and Jeremy.

Our appreciation to George J. Morales and Ferdinand V. Coroniti, Physics and Astronomy Department, UCLA, for most of the above obituary.