Nuclear Astrophysics

The nuclear fusion that occurs inside stars creates all the elements necessary for life and scientists at Sanford Lab want to understand how it happens.

Building the heavy elements

Astrophysicist and science fiction author Carl Sagan said, "We are made of stardust." And he was right. The nuclear burning inside of collapsing stars produces all of the elements heavier than iron, all of which make up and sustain life on Earth: carbon, nitrogen, iron, calcium. Even lead, gold and the rock beneath our feet come from stars. CASPAR, the Compact Accelerator System for Performing Astrophysical Research, researches this process from nearly a mile underground.

17 miles

The circumference of the Large Hadron Collider (LHC) in Switzerland

50 feet

The length of the CASPAR accelerator on the 4850 Level of Sanford Lab

Accelerating particles

Particle accelerators use electrical fields to create a beam of particles that are then fired toward a target. The beam travels in a vacuum through a beam pipe that is guided by magnets. The vacuum removes obstacles that can cause friction. CASPAR researchers use a low-energy, Van DeGraff accelerator to fire a beam of alpha particles at various targets, including helium and neon gas.

What is neon?

Neon is a noble gas found in Earth’s atmosphere. Colorless and odorless, it has two-thirds the density of air. CASPAR researchers plan to use the 22Ne isotope because it releases the same neutrons that fuel nuclear reactions in stars, producing a large amount of the heavy elements in the universe.

Neutrinos: Spies of the sun


Essentially, all elements are created in stars. But it’s the elements that are heavier than iron that interest members of the CASPAR collaboration. In which stellar environment were those elements created? CASPAR’s goal is to mimic the nuclear reactions that happen in stars that are a bit ‘older’ than our sun. If they we can do that, it could help complete our picture about how the elements in our universe are built

Read more about CASPAR