Cornelius Tobias, a founding member of Berkeley Lab's Donner Laboratory and a renowned pioneer in studying the biological effects of cosmic rays and other ionizing radiation, died of cancer on May 2. The man affectionately known to his colleagues as "Toby" was 81.

CORNELIUS "TOBY" TOBIAS

"Toby was an institution all by himself," said Mina Bissell, head of Berkeley Lab's Life Sciences Division. "He had many faithful followers and students and was a charismatic leader and teacher."

Said long-time colleague Aloke Chatterjee, "Dr. Tobias was a man of great vision and full of ideas. In 10 minutes he could easily come up with 11 ideas and, astonishingly, most of them would work. His contributions in fundamental radiobiology, space radiation biology and cancer therapy with heavy ions have had major impacts throughout the world. He was a great teacher, a great leader and a great humanitarian."

Tobias' career at the Laboratory spanned more than 40 years. He started in 1942 and officially retired in 1987, but continued to be active in research at the Lab for the rest of the decade. In addition to his position with the Laboratory, he was also a professor of medical physics at UC Berkeley. Among the many honors he received during his career was the 1963 E.O. Lawrence Award.

Born in Budapest, Tobias came to UC Berkeley in 1939 as a Hungarian-American Fellowship recipient after earning his B.S. in physics at the Technical University in Budapest. He obtained his Ph.D. in nuclear physics from Cal in 1942 under Lab legends Emilio Segrč and Luis Alvarez, and became one of the first researchers to apply a physical sciences background to the study of biology and medicine. That was the year he teamed with John Lawrence to form Donner Laboratory which, with its proximity to the 60-inch cyclotron as a source of radioactive isotopes, became the birthplace of nuclear medicine. He became a U.S. citizen in 1948.

With his knowledge of nuclear science and isotopes, Tobias was a valuable member of the Donner group that began the use of radioisotope tracers to study biomedical conditions in humans.

The first of these tracers, carbon-11, was used to investigate, among other phenomena, how pilots developed the "bends" at high altitudes. Tobias also provided a mathematical framework for the analysis of tracer turnover in the human body which led to the discovery that inert xenon gas, under sub-atmospheric pressures, can be an effective anesthetic.

Tobias was best-known for his radiobiology studies of high linear energy transfer (LET) radiation, and in the application of high LET radiation to cancer research and therapy. Perhaps his most famous work started as a series of experiments conducted in 1970 at the 184-Inch Cyclotron to explain the mystery behind the peculiar flashes and streaks of light reported by Edwin Aldrin and the other Apollo-11 astronauts after their 1969 moon mission.

CORNELIUS TOBIAS DONNED A BLACK HOOD TO KEEP OUT THE LIGHT BEFORE EXPOSING HIS EYES TO A BEAM OF FAST NEUTRONS IN A 1970 EXPERIMENT AT THE 184 INCH CYCLOTRON.  HELPING TO POSITION TOBY IN THE BEAMLINE ARE JOHN LYMAN (LEFT) AND RALPH THOMAS.

Donning a special black hood, Tobias exposed his own eyes to a variety of low-dose beams and saw the same display of lights. A report by he and colleagues John Lyman and Tom Budinger attributed the visual effects to helium ions (alpha-particles) and high-energy neutrons colliding with atoms in the eyes. They subsequently identified the source of the lights witnessed by the astronauts as cosmic rays, a phenomenon that Tobias had predicted nearly 20 years earlier.

Tobias would continue these and other experiments in space biology on the Bevatron which was capable of producing artificial cosmic rays through the acceleration of nitrogen ions to billions of electron volts of energy. He would eventually help develop much of the technology required to conduct biophysical experiments with particle beams, and became a leader in the use of heavy ion beams for the treatment of certain deadly cancers which could not be treated through conventional surgery.

Said another long-time colleague and close friend, Eleanor Blakely, "Professor Tobias' legacy is the large number of individuals worldwide to whom he imparted scientific curiosity for peaceful applications of radiation sciences. He was a man of high integrity, and many will miss him."

Tobias is survived by his son, Martin, his daughter, Eve Lippold, and two grandchildren, Julie Stier and Karen Lippold. His wife of 55 years, Ida, died in 1998. A private service was held for him in Eugene, Oregon on May 6. Those wishing to make a donation in Tobias' name should contact the Alzheimer's Association.

Additional information:

• Oral history of Cornelius Tobias: "Human Radiation Studies, Remembering the Early Years"