Accelerate your lab

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No caption. Photo by Carol Hsin.

Smashing atoms together is no longer just science fiction — researchers have been doing just that on Science Hill for more than 40 years.

Since the late 1960s, Yale researchers have used the particle accelerator at the Wright Nuclear Structure Laboratory on Science Hill to examine properties of the atomic nucleus, physics professor Andreas Heinz said. By analyzing data from the experiments, researchers have helped explain how an atomic nucleus is held together, physics professor Volker Werner said.

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Although the nucleus is a complex system, experiments have shown that it exhibits regular behaviors, such as sending out fixed amounts of radiation.

“We would assume that the nucleus would be an extremely chaotic system, but as it turns out, they exhibit very regular patterns,” Heinz said.

In order to study atomic nuclei and the force that holds them together, researchers must use probes on a similar scale to the nuclei. At the Wright Nuclear Structure Laboratory, beams of charged particles collide with nuclei at speeds as high as 60,000 kilometers per second, researchers said. Because positively charged nuclei repel each other, researchers use the particle accelerator to generate enough energy into the system to overcome the repulsion.

“If you want to study the structure of a mosquito, don’t hit it with a truck,” Werner said.

In the accelerator, positively charged beams that leave the accelerator at 10 to 20 percent the speed of light eventually collide with a nucleus, which causes it to emit gamma radiation, or highly charged light, Heinz said. Gamma radiation detectors, he added, keep track of the number, interval and energy level of the rays the nucleus emits. Researchers then use this data to determine properties of the nucleus, Heinz said. For example, if the emitted gamma rays have similar energy levels, scientists can figure out that the nucleus is spherical, Werner said.

However, the particle accelerator at the Wright Nuclear Structure Laboratory isn’t powerful enough to conduct experiments about the structure of protons and neutrons, said physics professor John Harris, who is the director of the particle accelerator but does not conduct his research there. Instead, he conducts his research at Relativistic Heavy Ion Collider at the Brookhaven National Laboratory in New York and at the Large Hadron Collider in Geneva, Switzerland.

But many experiments are still being conducted at the Wright Nuclear Structure Laboratory, physics professor Richard Casten GRD ‘67 said. The particle accelerator at the laboratory was used for 4,300 hours last year, Casten said.

So far, this research has no direct applications, said Mark Heinz, a postdoctoral researcher. But the equipment required for these studies push the boundary of technology, he added.

The Wright Nuclear Structure Laboratory was completed in 1964 with support from the National Science Foundation.

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