The American Physical Society has awarded Richard Casten, the D. Allan Bromley Professor of Physics, the 2011 Tom W. Bonner Prize in Nuclear Physics.
Specifically, Casten was recognized “for providing critical insight into the evolution of nuclear structure with varying proton and neutron numbers and the discovery of a variety of dynamic symmetries in nuclei.”
As an experimental nuclear physicist, Casten studies nuclei — the tiny centers of atoms made up of neutrons and protons — and developed a technique to predict the way in which the nucleus’ structure changes depending on the number of protons and neutrons it contains. The method involves a quick calculation that can replace the need for hours of supercomputing time while still giving an idea of the structure of the nucleus.
In addition, Casten also studies dynamical symmetries, which involve the nuclear shape, its quantum numbers, and oscillations and describes its overall behavior.
“It’s sort of like looking at a battle as a whole instead of the individual soldiers involved,” he says. While we normally think of nuclei as being tightly packed spheres, Casten points out that they in fact take on different shapes and forms. For instance, the nucleus of one particular atom is like a pressed balloon that oscillates in and out, he says, while another is like a vibrating, wobbling football.
A former director of Yale’s Wright Nuclear Structure Laboratory, Casten is now involved in the development of a new half-billion-dollar facility being planned for Michigan State University that will allow physicists to study a much wider range of nuclei.
While there are 273 stable nuclei, there are about 7,000 others that are so unstable they are annihilated mere fractions of a second after forming — a long time in the nuclear world, where physicists can study what goes on in a nucleus in less than a millionth of a second. As a result, this much larger pool of nuclei is now becoming accessible.
“Being able to study these exotic nuclei is really changing our paradigms,” Casten says.
The Tom W. Bonner Prize was endowed in 1964 as a memorial to Rice University physicist Tom W. Bonner by his friends, students and associates.
