Thomas Howard Stix, one of the most original thinkers and leading developers of the field of plasma physics, died April 16 in Princeton, NJ. He was 76 years old and professor emeritus in astrophysical sciences at Princeton University. The cause of death was leukemia.

Professor Stix will be remembered not only as an outstanding scientist, educator, innovator and inventor; he will also be remembered for his warmth, for his humor, and for his genuine concern for people.

Born on July 12, 1924, in St. Louis, he served in the United States Army from 1942 to 1945. After receiving his BS from the California Institute of Technology in 1948 and his Ph.D. from Princeton in 1953, he joined Project Matterhorn, then a small, classified project on Princeton's Forrestal Campus. The project aimed to harness fusion energy for peacetime use. Project Matterhorn grew fast, and, in 1961, when Thomas Stix headed the experimental division, its name was changed to the Princeton Plasma Physics Laboratory.

Stix's work revolutionized research in plasma physics by showing how waves could heat plasma. This early work was presented at the Second International Atoms for Peace Conference in Geneva in 1958, held soon after the major nations working on controlled thermonuclear fusion research had agreed to declassify their work.

In 1962, Stix published his classic text, "The Theory of Plasma Waves," the same year in which he received appointment to Professor of Astrophysical Sciences at Princeton University. Enormously influential, this textbook both explored and formalized the growing subject of waves in plasma, both for laboratory and astrophysical applications. It was the book that served to educate and inspire more than one generation of plasma physicists.

Stix showed how microwaves, injected from antennas or waveguides, could heat plasma to thermonuclear temperatures -- or tens of millions of degrees Fahrenheit, while confining it within powerful magnetic fields. Among his inventions is a coil structure in which sections of coil were alternately wound around the device clockwise and counter clockwise. Later known as a Stix coil, this structure coupled radio frequency waves at ion cyclotron frequencies into the plasma. Stix also contributed importantly to the theory of stochastic and chaotic behavior of particles and magnetic fields in plasmas.

Recipient of numerous awards, including a Guggenheim Fellowship in 1969, Professor Stix was awarded the 1980 James Clerk Maxwell Prize, the American Physical Society's highest award in the field of plasma physics. This award recognized his pioneering role in developing and formalizing the theory of wave propagation and wave heating in plasmas. In 1999, he was awarded Fusion Power Associates Distinguished Career Award.

In 1991, Princeton University recognized his contributions as a teacher and educator in its awarding him its first "University Award for Distinguished Teaching."

Among his professional responsibilities, he was elected in 1962 Chair of the Division of Plasma Physics of the American Physical Society. In 1978, Stix was appointed Associate Director for Academic Affairs at PPPL, and for many years he was Director of the Program in Plasma Physics at Princeton University. He spent three sabbaticals at the Weizmann Institute of Science in Israel.

Stix also embraced civic responsibility in the many communities in which he found himself. Chairing the American Physical Society Committee on International Freedom of Scientists, and for many years serving on the committee, he worked tirelessly on behalf of human rights and the political freedom of scientists worldwide. He served also on the American Physical Society Panel on Public Affairs. He chaired the Princeton United Jewish Appeal in 1954-55, and again in 1963-64. He served as Chair of the Princeton Hillel Foundation from 1972 to 1976. He also served the University in 1994 as Acting Director for the newly founded Princeton University Center for Jewish Life. He was on the board of the Princeton chapter of the American Jewish Committee and on the advisory board of the Princeton Senior Resource Committee.

In 1950, he married Hazel Sherwin. Longtime residents of Princeton, he and Hazel raised two children, Susan Sherwin Fisher of New York City and Dr. Michael Sherwin Stix of Lexington, MA. In addition to his wife and children, and four grandchildren, he is survived by his brother Ernest Stix, a sculptor in St. Louis, MO, and his brother, John Stix, N.Y. stage director and long-time faculty member of Julliard.

Professor Thomas Stix was known also for his love of life. He and his wife of 50 years, Hazel, enjoyed traveling worldwide. He enjoyed windsurfing, swimming, and snorkeling well into his seventies. He was also an avid skier into his seventies, skiing with his children and grandchildren at Alta and Snowbird, Utah. A devoted grandfather, he learned last year to scooter with his two grandsons around Central Park.

A memorial service will be held at the Princeton Jewish Center on Monday, April 23 at 10:30. The family will be receiving visitors at their home afternoons Monday through Thursday 1:00-4:00 and 7:00-9:00. In lieu of flowers, the family requests that donations be made to the Princeton Senior Resource Center, the New Israel Fund, or the American Jewish Committee.

Expressions of sympathy may be sent to Hazel Stix, 231 Brookstone Drive, Princeton, NJ 08540.