George Cowan, 92, Dies; Helped Guide Nuclear Era
By DOUGLAS MARTIN
Published: April 26, 2012
George Cowan, a chemist who helped build the first atomic bomb, detect the first Soviet nuclear explosion and test the first hydrogen bomb, died on Friday at his home in Los Alamos, N.M. He was 92.
The Santa Fe Institute, a scientific research center that Dr. Cowan headed and helped found, announced the death.
For his many contributions, Dr. Cowan was awarded the federal Energy Department's highest honor, the Enrico Fermi Award, and the highest honor given by the Los Alamos National Laboratory, the Los Alamos Medal. The citation on his Los Alamos award called him ''the driving force in the early radiochemical evaluations of nuclear weapons.''
Dr. Cowan began thinking about the possibility of a bomb in 1938, when he brought a clipping about nuclear fission to his physics professor and asked him to talk about the possibility of a weapon based on splitting the atom. His professor at Worcester Polytechnic Institute in Massachusetts made a convincing argument that it would not happen, but when Dr. Cowan graduated three years later, the professor referred him to Eugene Wigner, a physicist at Princeton.
Dr. Wigner was conducting experiments on the atom's structure with Princeton's atom smasher, and the experimenters needed uranium. Dr. Cowan was sent to a laboratory in Massachusetts to retrieve a kilogram of uranium. He carried it back to Princeton in a convertible driven by a colleague, the precious cargo between his legs and covered in dry ice.
That experience led him to the Manhattan Project, the federal government's secret effort to develop the atomic bomb.
Dr. Cowan was at Oak Ridge, Tenn., to help measure plutonium production; at Columbia University to study the energy of neutrons; and at Los Alamos to help track plutonium inventories. He went to Bikini Atoll in the Pacific for nuclear detonation tests.
It was unusual for a scientist to be sent to so many sites. Dr. Cowan said that his expertise made him valuable as a troubleshooter, and that his being unmarried was also helpful.
In 1946 he married a fellow chemist from the Manhattan Project, Helen Dunham. They were married 65 years and had no children. She died last year.
After World War II, Dr. Cowan earned a doctorate from Carnegie Institute of Technology (now Carnegie Mellon University). He returned to Los Alamos in 1949. Weeks after his arrival, an American surveillance plane detected high levels of radiation emanating from the Soviet Union. Dr. Cowan was named to the team that analyzed the data. The group pinpointed the detonation of the Russian bomb to within an hour on Aug. 29, 1949.
''It's time to write our summary,'' Hans Bethe, the group leader, said, according to Dr. Cowan. ''It can be a long document about what we don't know or a short one about what we know.''
''We wrote a short one,'' Dr. Cowan said.
President Harry S. Truman ordered the development of a more powerful weapon, the hydrogen bomb, to counteract the Soviet device. Dr. Cowan became part of the group that developed it. He was on the command ship, the Estes, when it was successfully detonated on Nov. 1, 1952.
George Arthur Cowan was born on Feb. 15, 1920, in Worcester and attended local schools before moving on to Worcester Poly. He was 21 when he joined Dr. Wigner, a future Nobel Prize winner, at Princeton.
Dr. Cowan argued that nuclear weapons development contributed to scientific progress, pointing to the creation of two new elements and 15 new isotopes in the first hydrogen bomb explosion. In 1965, he directed an experiment in which an underground nuclear explosion created fermium 257, the heaviest known isotope that can be created by neutron bombardment of lighter elements.
In a 1979 article in Scientific American, he reported the startling discovery that atomic reactions were going on almost two billion years ago. He said a natural fission reactor was formed in present-day Gabon when geological changes caused water to flow into pockets of uranium. This ''reactor,'' over its life span of several hundred thousand years, consumed some six tons of uranium 235.
Dr. Cowan assembled scientists in 1984 to start the Santa Fe Institute, which studies different sorts of complex systems. He founded the Los Alamos National Bank in the mid-1960s and was chairman for three decades. He was part of the group that in 1953 started the Santa Fe Opera, of which he was treasurer.
Dr. Cowan also served on the White House Science Council during the Reagan administration, where he reunited with Edward Teller, a leader in developing the hydrogen bomb. Dr. Teller lobbied for President Ronald Reagan's missile defense system, popularly called ''Star Wars,'' while Dr. Cowan opposed it because he did not think it would work.
The two had been part of a regular poker game at Los Alamos. Dr. Cowan said he particularly liked to play with Dr. Teller ''because he had a tendency to draw to inside straights'' -- generally a losing hand.
This is a more complete version of the story than the one that appeared in print.
PHOTO: George Cowan, shown in 2005, helped build the atomic bomb. (PHOTOGRAPH BY LOS ALAMOS NATIONAL LABORATORY, VIA ASSOCIATED PRESS)