Fermilab Today

On Aug. 6, MicroBooNE, a liquid-argon time projection chamber, or LArTPC, recorded images of the tracks of cosmic muons, particles that shower down on Earth when cosmic rays collide with nuclei in our atmosphere.

"This is the first detector of this size and scale we've ever launched in the U.S. for use in a neutrino beam, so it's a very important milestone for the future of neutrino physics," said Sam Zeller, co-spokesperson for the MicroBooNE collaboration.

Picking up cosmic muons is just one brief stop during MicroBooNE's expedition into particle physics. The centerpiece of the three detectors planned for Fermilab's Short-Baseline Neutrino program, or SBN, MicroBooNE will pursue the much more elusive neutrino, taking data about this weakly interacting particle for about three years. When beam starts up in October, it will travel 470 meters and then traverse the liquid argon in MicroBooNE, where neutrino interactions will result in tracks that the detector can convert into precise three-dimensional images. Scientists will use these images to investigate anomalies seen in an earlier experiment called MiniBooNE, with the aim to determine whether the excess of low-energy events that MiniBooNE saw was due to a new source of background photons or if there could be additional types of neutrinos beyond the three established flavors.

One of MicroBooNE's goals is to measure how often a neutrino that interacts with an argon atom will produce certain types of particles. A second goal is to conduct R&D for future large-scale LArTPCs. MicroBooNE will carry signals up to two and a half meters across the detector, the longest drift ever for a LArTPC in a neutrino beam. This requires a very high voltage and very pure liquid argon. It is also the first time a detector will operate with its electronics submerged in liquid argon on such a large scale. All of these characteristics will be important for future experiments such as the Deep Underground Neutrino Experiment, or DUNE, which plans to use similar technology to probe neutrinos.

"The entire particle physics community worldwide has identified neutrino physics as one of the key lines of research that could help us understand better how to go beyond what we know now," said Matt Toups, run coordinator and co-commissioner for MicroBooNE with Fermilab Scientist Bruce Baller. "Those questions that are driving the field, we hope to answer with a very large LArTPC detector."

Another benefit of the experiment, Zeller said, is training the next generation of LArTPC experts for future programs and experiments. MicroBooNE is a collaborative effort of 25 institutions, with 55 students and postdocs working tirelessly to perfect the technology. Collaborators are keeping their eyes on the road toward the future of neutrino physics and liquid-argon technology.

"It's been a long haul," said Bonnie Fleming, MicroBooNE co-spokesperson. "Eight and a half years ago liquid argon was a total underdog. I used to joke that no one would sit next to me at the lunch table. And it's a world of difference now. The field has chosen liquid argon as its future technology, and all eyes are on us to see if our detector will work."

—Ali Sundermier

Photo of the Day

Frog spotting

This northern leopard frog recently hopped by the SiDet building. Photo: Stephanie Timpone, PPD

In the News

A tale of two neutrino labs

From Medium, Aug. 11, 2015

Editor's note: This Medium blog post was written by Representative Randy Hultgren.

Hundreds of miles apart and hundreds of feet below the Earth's surface, two laboratories are pushing basic scientific research to the outer boundaries of the known universe.

A new experiment will send tiny particles called neutrinos 800 miles through the Earth's crust from the Fermi National Accelerator Laboratory in Batavia, Illinois (a.k.a. Fermilab, within the 14th Congressional District I represent) to the Sanford Underground Research Facility (Sanford Lab) in Lead, South Dakota. The Deep Underground Neutrino Experiment (DUNE) may revolutionize our understanding of the matter and energy that compose our mysterious universe as scientists at both labs — and around the world — study these subatomic particles as they travel through the Earth and through space.

My family and I recently had the privilege of attending the grand opening of the Sanford Lab Homestake Visitor Center. As a member of the House Science, Space and Technology Committee in the U.S. House of Representatives, and co-founder of the House Science and National Laboratories Caucus, I was thrilled to help celebrate this key partner of Fermilab.

From the Accelerator Division

Review marathon — a job well done

Vaia Papadimitriou

Vaia Papadimitriou, associate head of the Accelerator Division and LBNF Beamline manager, wrote this column.

The LBNF beamline (see figure below) will be located at Fermilab and will aim a wide-band neutrino beam toward the DUNE underground detectors placed at the Sanford Underground Research Facility in South Dakota.

The initial proton beam power is expected to be 1.2 megawatts, to be provided by the proposed PIP-II accelerator complex upgrades. The beamline facility is also designed to be upgradeable to 2.4 megawatts, to be provided by the proposed PIP-III. This will enable DUNE, Fermilab's future flagship experiment, to carry out a compelling research program in neutrino physics at much higher beam power than any other operating accelerator-based neutrino experiment in the world.

Although over 75 percent of the 60-plus person Beamline team is based in the Accelerator Division, the team draws colleagues from almost every division and section at Fermilab, as well as from other national institutions, such as Brookhaven National Laboratory, Northwestern University, University of Texas at Arlington, and international collaborating institutions, including CERN and Rutherford Appleton Laboratory, and contractors. We have scientists, engineers, physicists, designers, technicians, environment, health and safety specialists, alignment specialists, project controls specialists, fabrication specialists, procurement specialists — the list goes on and on.

During the past two years the LBNF Beamline team went through six technical design reviews, a comprehensive independent design review for the entire beamline, and three Critical Decision 1 (CD-1) related design and cost/schedule reviews. This is a marathon to run, but last month, we successfully crossed the finish line!

The reviewers were very complimentary of the team. The DOE CD-1 Refresh Review Committee commented on July 16 that they were "impressed by the quality and depth of the presentations," that "the beamline design team is highly qualified and was well prepared," and that many in the team "have worked on the previous neutrino beam lines and bring that world-leading experience to the table." The Committee also found that "the design is very mature, being based on five years of previous work form LBNE and LBNO, and is well beyond the CD-1 level in most instances."

I would like to thank the colleagues who assist in leading this outstanding team, in particular for all their efforts that enabled us to go successfully through this review marathon, namely, the Accelerator Division's Beamline Project Engineer Salman Tariq, Technical Advisor Jim Hylen, Chief Electrical Engineer George Krafczyk, L3 Leaders Rich Andrews, Tom Kobilarcik, Craig Moore, Phil Schlabach, and the Neutrino Division's Alberto Marchionni.

The LBNF Beamline Project would not be possible without the hard work from many colleagues in the Accelerator, Neutrino, Particle Physics and Technical divisions, the Computing Sector, the FESS and ESH&Q sections, the collaborating Institutions and contractors, the DUNE Beam Simulation Group, the Beamline Technical Board and the LBNF Project Office.

I congratulate and thank the entire Beamline team and each colleague separately for everybody's continued excellent work and dedication, which led to such an outstanding performance during the CD-1 Refresh Review. We are now ready for the next challenge in the design phase of the LBNF Beamline and look forward to designing and building it, working together with all our international partners.

This illustration shows the longitudinal section of the LBNF beamline facility at Fermilab. The beam comes from the right, where protons are extracted from the MI-10 straight section of the Main Injector.

Safety Update

ESH&Q weekly report, Aug. 11

This week's safety report, compiled by the Fermilab ESH&Q Section, contains three incidents.

An employee injured his back while working in an awkward position to adjust the alignment of beam pipe. This is a DART case.

An employee was stung on the neck, knees and left foot while on travel in Brazil.

An employee felt something enter his left eye after using a gas powered-saw to cut a piece of culvert. He washed his eye out with water and reported to the Medical Office. This is a pending claim.

See the full report.

In the News

The little particles that might help explain why we're here

From Forbes, Aug. 9, 2015

One abiding mystery about the cosmos is why there's more matter than antimatter. Nobody's complaining about that imbalance: if there had been precisely the same amount of both in the universe's earliest moments, we wouldn't be here, because everything would have destroyed itself in an instantaneous flash of gamma rays.

However, physicists don't quite know why the universe started off with just a teeny bit more matter than antimatter. One possible key to that mystery lies with the most abundant and least-massive particles we know of: neutrinos. These particles barely interact with atoms, but they occupy a unique position in that they change their nature as they travel. That change is known as neutrino oscillation, and experiments studying the phenomena are designed with the hope of measuring neutrino masses (which are still unknown, though we have a strong limit on how big they can be) and precisely how they change.