News Release

St. Louis chemist wins national award for spinning, shapely nuclei

Grant and Award Announcement

American Chemical Society

Demetrios G. Sarantites of St. Louis, Mo., will be honored March 25 by the world's largest scientific society for gaining insights about the nuclei of atoms and how they decay by spinning them so rapidly they assume exotic shapes. He will receive the 2003 Glenn T. Seaborg Award for Nuclear Chemistry from the American Chemical Society at its national meeting in New Orleans.

"The main idea is to study the shapes of nuclei, because the shape determines how the atomic nucleus decays," said Sarantites, a nuclear chemist and professor at Washington University in St. Louis. "We can make many nuclei shaped like footballs, doorknobs or pears, and then we measure everything that comes out."

Nuclei spun into football shapes, for example, decay faster than those shaped like spheres -- lifetimes that last on the order of femtoseconds, or million-billionths of seconds.

"Imagine two balls hitting each other off-center, sufficiently hard to stick together but not too hard -- then one ball, or rather nucleus, may split and you'd have nuclear fission, not fusion," he explained. "But if they hit just right, off-axis, you can imagine that causing them to spin. We can make these exotic shapes in about one out of every 10,000 successful collisions."

Sarantites' research team has spun nuclei of a zirconium isotope over 2 million-billion-billion revolutions per second, for example. At those speeds the centrifugal forces stretch the nuclei out of their conventional shapes, and their energy 'fingerprints' change accordingly. The gamma-ray profile of a calcium isotope has no regular pattern when spherical; but when highly deformed, "it looks like a picket fence," he said.

Part of his research is developing the instruments to detect and study nuclei. "I have some really fun toys," he said. "One is a 6-inch ball with 96 detectors to sense protons, alpha particles, you name it. There are about 10 computers that are working on data just from it."

Sarantites, a native of Greece, said he's been interested in nature as long as he can remember: "Books didn't say enough about how nature makes things go. I wanted to always learn more," he said. The nuclear chemist went on to receive his undergraduate degree from the Technical University of Athens in 1956 and his Ph.D. from the Massachusetts Institute of Technology in 1963.

###


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.