Dr. Stone joined the Applied Physics Laboratory in 1949 and spent about 40 years there. He was a specialist in radar-guided missiles, controlled thermonuclear fusion and geothermal energy. He supervised a plasma physics group, among other groups and divisions.

During World War II, Dr. Stone worked at the Massachusetts Institute of Technology Radiation Laboratory on developing microwave radar. He subsequently helped edit the lab’s comprehensive series on radar.

After the war, Dr. Stone was briefly a scientific liaison officer in the U.S. Embassy in London and headed a scientific intelligence division in the newly established CIA.

Albert Mordecai Stone was a Boston native and a 1934 honors graduate of Harvard University. In 1938, he received a doctorate in physics at MIT, where he was elected to the Sigma Xi scientific honor society. He later was a fellow of the American Physical Society and the American Association for the Advancement of Science.

Over the years, he was a U.S. delegate to conferences on the peaceful uses of atomic energy and served on an advisory board to the Federal Emergency Management Agency that addressed anti-terrorism concerns.

He was a director of the General Instrument Corp. and Neuberger Berman equity funds. His other memberships included the Cosmos Club.

His avocations included golf, tennis, skiing and bridge.

His first marriage, to Louisa Van Wezel, ended in divorce. Survivors include his wife of 44 years, Francesca Gobbi Stone of Bethesda; three children from his first marriage, Anthony Stone of Atlanta, Katherine Stone of Los Angeles and Daniel Stone of Reston; a brother; and three grandchildren.

— Adam Bernstein