Students at South Dakota Mines
are leading the way in calibrating the sensors that will detect and track tiny
flashes of light inside the massive Deep Underground
Neutrino Experiment (DUNE) that will be constructed at the Sanford Underground
Research Facility (SURF).
DUNE will advance the study of the elusive ghost
particle known as the neutrino. The scale of DUNE is mind boggling.
It’s one part of the Long Baseline Neutrino Facility
(LBNF), hosted by Fermi National Accelerator Laboratory. A particle accelerator at Fermilab in Illinois
will shoot a neutrino beam more than 800 miles straight through the Earth to a
DUNE particle detector 4,850 feet below ground at SURF. The detector is composed
of seven-story-high tanks filled with liquified argon that must be kept at a
temperature around 300 below zero °F. The neutrinos bombarding the tanks will
occasionally hit an argon atom, causing a tiny flash of light. The nature of
the light generated by these interactions will give researchers a new
understanding of the mysterious neutrinos and help answer several fundamental
questions about the nature of matter and the evolution of the universe.
The DUNE collaboration includes more
than 1,400 people from 200 universities and institutions across more than 30
nations. Ian Helgeson is completing his undergraduate degree in mechanical
engineering at Mines. He spent the past year helping build components of the
ultraviolet (UV) photon detector monitoring system. He says the chance to do hands-on work on a
world-class experiment as an undergraduate is an incredible opportunity. “One
of the best things is being able to collaborate with others all around the
world who are working on this gigantic project. The design criteria are very
stringent and the components we build have to interface perfectly with
everything else in the experiment in order to achieve groundbreaking science in
the end,” says
Helgeson.
One
of the challenges Helgeson helped tackle was creating extremely efficient fiber
optic connections. “To
reduce light loss in this experiment we had to polish the ends of the optical
fibers to a high precision. This process took hours and hours to do by hand.
Basically, the optical fiber needs to be perfectly flat because any light loss affects
the correct operation of the photon detector monitoring system. Part of our job
was to build tools to reduce this effort and improve quality of the fiber and
explore future solutions as automatic polish machines that could expedite the
preparation time of the optical fibers that will be needed for DUNE.”
Mines student Kole Pickner just
finished his master’s degree in mechanical engineering while working on the
project. Pickner also worked on the photon detector monitoring system for DUNE. The detectors inside DUNE
are like the eyes of the experiment, and in a sense, Pickner’s job was to teach
these eyes how to see. The system Pickner helped design and build had to be
exceedingly robust, because once a component is installed inside DUNE and the
experiment is filled with liquid argon, it can’t be opened up. “You can’t just
open a door in 10 or 15 years to fix a broken component, the parts we build
must last for the entire life of the experiment. That’s an additional
engineering challenge here,” says Pickner.
Pickner just graduated and has accepted a job with Lockheed Martin Space
in Denver where he will work on several NASA projects including missions to
Mars.
A physics doctoral graduate student at
Mines Jairo Rodriguez, is leading the installation of the fiber optic
cables and the photon detector monitoring system components
inside the ProtoDUNE
detector at CERN in Switzerland. Rodriguez’ work involved installing the
systems he built with his colleagues and integrating them with the rest of the
components inside the prototype version of the DUNE detector. “The model often
needs changes when transitioning to real life, and we are constantly adjusting
our design to optimize performance,” says Rodriguez.
The photon detector monitoring system,
designed and built by this team, is expected to start operation later this year.
South Dakota Mines assistant professor of physics, David A. Martinez Caicedo,
Ph.D., gives praise to this team of students for their hard work and success. Dr.
Martinez group’s work on this project is funded by the U.S. Department of
Energy. He also credits many collaborators who are working on DUNE at other
institutions. “We worked really closely with the Argonne National Laboratory
team led by Dr. Zelimir Djurcic and learned from their experience with photon
detector monitoring systems in addition to many others around the nation. These
collaborations have proven vital for the successes of our students and the
project overall,” says Martinez.
Martinez notes that the success of
science experiments of this size is not just thanks to the ingenuity of researchers alone.
“There is a lot that goes into
building these components and how they interface with all the other components
in the detector, an incredibly important part of this success is supply chain
management and administration,” says Martinez. “It’s a tough job, and we give
huge thanks to Connie Krosschell, the physics department secretary, who was
instrumental in expediting and following up on all the procurement of the key
components to keep the project on time.”