In a cavern buried beneath a mile of rock at the
Sanford Underground Research Facility, a School of Mines team has spent the
last year assembling an accelerator that could alter the scientific world with
quiet bursts of energy.
The Compact Accelerator System Performing
Astrophysical Research (CASPAR) experiment hopes to understand the origins of
the universe by mimicking nuclear fusion in stars, studying the smallest scale
possible to understand the largest scale possible.
Led by South Dakota Mines’ Dr. Frank Strieder of the
Department of Physics, the team of scientists includes researchers from the
University of Notre Dame and the Colorado School of Mines, as well as seven
Mines students—three doctoral students and four undergraduates. Strieder
designed the 45-foot-long accelerator and spent a year purchasing or machining
parts and then assembling them.
Data collection is expected to begin within the next
month.
The idea behind the experiment is to generate the type
of energy inside a star, allowing scientists to understand how stars were
formed and where they are in their lifespan, which could lead to other
discoveries about life in the universe.
One kilometer away inside another cavity of the
sprawling deep underground laboratory, Ray Davis observed for the first time 50
years ago that neutrinos came from the sun. Davis earned the Nobel Prize for
his discovery.
“We know basic principles. We know stars produce energy
by nuclear fusion, but there are things we need to understand better, including
how the elements between iron and uranium on the elements chart originated,”
says Strieder.
Only hydrogen and helium resulted from the so-called
Big Bang almost 14 billion years ago. “All the other elements around us,
potassium in our bones, the air we breathe, oxygen, carbon, all of these
elements were done in the stars, later in the universe,” says Strieder, whose
childhood fantasy of traveling into space morphed into a study of astronomy and
then astrophysics.
The experimental aspect of physics, to be able to work
with his hands designing and building accelerators, was attractive to him and
ultimately led him to the deep underground experiments, where results are
shielded from cosmic rays.
“It was always my dream to understand the stars, and I
ended up doing experiments a mile underground in the same place where Ray Davis
made his groundbreaking discovery of solar neutrinos. That was the proof that
solar energy is provided by nuclear reactions, and here we are studying nuclear
reactions. So everything is coming back full circle,” says Strieder.
Strieder previously worked with the world’s first
underground accelerator project, the Laboratory for Underground Nuclear
Astrophysics, at Gran Sasso Laboratory in Italy.