Exploding stars in the cellar, FSU Nuclear Physics charts new course

Florida State University’s nuclear physics laboratory, one of the premier nuclear research facilities on any college campus in the United States, is looking to its future among the stars—novas to be exact.

RESOLUT, a project to recreate the nuclear reactions in exploding stars, is in its final stages of preparation at FSU’s Superconducting Linear Accelerator Laboratory and will be instrumental in furthering astrophysics research worldwide.

"We are bringing the stars into the basement and studying them," said Ingo Wiedenhover, an assistant professor of physics who is heading up the project. The accelerator laboratory is located underground in FSU’s LeRoy Collins Research Laboratory.

RESOLUT is designed to recreate atomic nuclei that are believed to be the fuel of star explosions and may exist for only thousandths of a second before they disintegrate. Through a two-stage process the nuclei will be created in the accelerator and their properties measured before disintegrating.

These ions are so exotic and short lived that they cannot form under natural conditions on Earth, they can only be created in the accelerator, Wiedenhover said. RESOLUT will allow scientists for the first time to study and measure these nuclei to further an understanding of how stars are created and die.

"If you cannot study these nuclei in a microsecond, they’re gone," Wiedenhover said, "and RESOLUT will allow us to study them."

Among other things, the experiments with RESOLUT will help scientists worldwide to interpret data collected by a satellite launched from Kazakhstan in 2002 to study some of the most violent and exotic objects in the universe, such as black holes and neutron stars. The satellite, or International Gamma-Ray Astrophysics Laboratory, is part of an international astrophysics consortium headed by the European Space Agency.

FSU’s accelerator operates by firing a continuous beam of atomic nuclei through a slender steel tube reaching speeds of about 60 million miles per hour, or 10 percent the speed of light. At such speeds the nuclei will induce reactions when they collide into other nuclei contained in thin foils called the "target," which are located at the end of the beam path. The collisions rip apart the nuclei into their various components, which are then detected and analyzed in a variety of research instruments.

The accelerator is used in various types of nuclear physics research, including measuring gamma rays emitted from spinning nuclei and other reactions of these nuclei as they collide. The biggest discovery made using FSU’s accelerator resulted from experiments of so-called isobaric analog-states, which are states of nuclei in which a proton behaves as if it were a neutron, or vice versa. This project established that protons and neutrons can be understood as two separate states of the same particle even as they bind together creating the core of an atom.

The accelerator began operations in 1960 and has maintained its state of the art status through two major upgrades, the first in 1970 and the second in 1985. RESOLUT is the lab’s latest upgrade opening new research possibilities for a new generation of physicists and students.