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In deep underground neutrino experiment, CSU science rises to top

In deep underground neutrino experiment, CSU science rises to top
LBNF-DUNE graphic

CSU scientists are working on an international neutrino science collaboration, DUNE, that will send neutrino beams from Fermilab to the Sanford Underground Research Facility. Credit: Fermilab

What’s being billed as a new era in physics starts with two shovelfuls of dirt ­– one in Illinois, the other in South Dakota.

On July 21, scientists, engineers and partners around the world will gather in two places – Fermi National Accelerator Laboratory and the Sanford Underground Research Facility – to break ground on a massive global physics experiment called DUNE.

The International Deep Underground Neutrino Experiment (DUNE) involves close to 1,000 scientists and engineers from 31 countries and 165 institutions – including Colorado State University, since the project’s inception.

CSU’s fingerprints on DUNE

Among those who will attend the groundbreaking, to be held simultaneously at Fermilab in Batavia, Illinois, and 800 miles away at the Sanford Underground Research Facility in Lead, South Dakota, will be Robert J. Wilson, Colorado State University professor of physics and a key leadership figure in the long-awaited project. Wilson will attend the ceremony at the South Dakota site.

Robert J. Wilson

Robert J. Wilson, professor of physics

Wilson, a high-energy physicist who also works on a neutrino experiment in Japan called T2K, chairs the institutional board overseeing the $300 million DUNE project. Wilson also serves on the board of the South Dakota Science and Technology Authority, which operates the Sanford Underground Research Facility. This will be the eventual home of DUNE’s main neutrino detector, called the far detector. Major parts of the detector could be operational as soon as 2024.

CSU President Tony Frank is a board member of the Universities Research Association, which along with the University of Chicago, operates both Fermilab and the DUNE infrastructure, all on behalf of the U.S. Department of Energy.

CSU’s fingerprints on DUNE don’t end there. Among thousands of intricate components that go into an international project of this magnitude, Norman Buchanan, associate professor of physics at CSU, leads the design effort around one of DUNE’s most crucial elements, called the photon detector. Right now, Buchanan and his team of engineers and students are working toward testing current photon detector technologies at the CERN accelerator complex in Switzerland. The proof-of-concept run at CERN will be called ProtoDUNE, and will take place in approximately 2018. CSU research scientist Daniel Cherdack also leads an international team of DUNE scientists to develop analysis tools for key neutrino measurements.

Planning for a $300 million international physics experiment doesn’t happen overnight. Physicists at CSU have been working on DUNE or its previous iterations since 2003. It’s for this reason that the significance of the groundbreaking isn’t lost on Wilson or others.

“DUNE, as it’s now known, was conceived over a decade ago,” Wilson said. “Since then, scientists around the world, including at CSU, have worked tirelessly in the name of science to oversee its design and see it through to completion. Coming to this moment of breaking ground on DUNE is a dream come true for us all.”

Breaking ground in two places

To understand the scope and scale of the DUNE experiment, you could start by asking why a groundbreaking ceremony needs to take place in two different states.

It’s because the place where the neutrinos will get made, and where they will end up, are 800 miles apart.

In order to study neutrinos, scientists need to make them – a lot of them – in the form of beams that travel at near the speed of light. Fermilab, an accelerator complex that already makes neutrino beams for an ongoing experiment called NOvA (which Buchanan also works on, and helps to monitor from a control center in Fort Collins), will also make the neutrino beams for DUNE.

That beam will travel from Fermilab ­– 800 miles in about 4 milliseconds – to a 4-story-tall underground neutrino detector, called the far detector, at Sanford Underground Research Facility in South Dakota. When the beam passes through the detector in South Dakota, filled with 70,000 tons of liquid argon, a tiny fraction of the neutrinos in the beam will interact with the argon atoms. Scientists will record and study these neutrino-argon interactions at a scale and resolution the world has never seen.

The entirety of the infrastructure for DUNE will be housed at Fermilab and Sanford Underground Research Facility, and will include the neutrino beam, the DUNE detectors, and everything in between them. All these components make up what’s called the Long Baseline Neutrino Facility.

DUNE may explain why we’re here

The CSU scientists and students working on DUNE are part of a game-changing scientific endeavor that may one day explain why the universe is mostly matter, as opposed to equal parts matter and antimatter. To do so, all eyes are on the most abundant matter particle in the universe, the neutrino.

DUNE will enable scientists to look for differences in the behavior of neutrinos and their antimatter counterparts, antineutrinos, which could provide essential clues as to why we live in a matter-dominated universe that supports life as we know it. In other words, neutrinos could tell us why we are all here, instead of our universe having been annihilated into a structureless ball of energy just after the Big Bang.

In an equally unprecedented side project, DUNE will also watch for neutrinos produced by supernovae – dying stars. Scientists can take advantage of studying neutrinos that shoot out of supernovae to look for the formation of neutron stars or black holes. Finally, the DUNE neutrino detectors will allow scientists to look for the oft predicted but never observed subatomic phenomenon of proton decay, a process that could lead to a unified theory of energy and matter.

Detecting non-beam neutrinos    

Norm Buchanan

Norm Buchanan, associate professor of physics

Buchanan’s photon detector team has an essential job: Being able to sense neutrinos that come in from places other than the neutrino beam Fermilab will provide.

The photon detector, a component of the DUNE far detector, is designed to sense high-energy ultraviolet light. This light gets emitted when neutrinos interact with the liquid argon sitting in the DUNE detector. By allowing scientists to see exactly when that light was detected, they can pinpoint exactly when a neutrino passed through the detector, and at what point in space.

The photon detector will allow DUNE scientists to look at things like proton decay, supernovae and dark matter signatures – all things that would occur at unpredictable times. This is in contrast with the experiment’s neutrino beams, which will be turned on at predetermined times.

“This is why it’s so important to have the detectors in before the beam,” Buchanan said. “The photon detectors tell us where the neutrino event happens, and they tell us that by giving us the time of the event.”

DUNE is funded by the U.S. Department of Energy’s Office of Science, in conjunction with CERN and dozens of international partners.

Anne Manning

Anne Manning