Creating the largest neutrino detectors in the world

2017-07-22   PHYS

Physical Sciences Laboratory electronics technician Andy Arbuckle soldering 150 micron CuBe wire on the anode panel assembly (APA). Four underground detector modules in South Dakota will each be two-thirds the size of a football field and comprise 150 APAs. Credit: UW-Madison Physical Sciences Laboaratory A new era in neutrino physics in the United States is underway, and UW–Madison's Physical Sciences Laboratory (PSL) in Stoughton is playing a key role.

The Long-Baseline Neutrino Facility, home to the $2 billion Deep Underground Neutrino Experiment (DUNE), will eventually send particles 800 miles through the earth from a lab outside Chicago to a mile-deep in an inactive gold mine in the Black Hills of South Dakota.

Neutrinos are little-understood, but their role in understanding matter and the dynamics of the universe is growing as science continues to learn more about the enigmatic particles through a constellation of new and exotic detectors, including the new DUNE experiment.

Groundbreaking ceremonies for the Long-Baseline Neutrino Facility (LBNF) will be held simultaneously today at the Sanford Lab in South Dakota and at Fermilab in Illinois.

The facility will provide the neutrino beam and the infrastructure that will support the DUNE detectors, taking advantage of Fermilab's powerful particle accelerator complex and Sanford Lab's deep underground areas within a long, existing tunnel carved out during the gold mining days of the 1930s.

Once the first shovel of earth is turned, crews will excavate more than 800,000 tons of rock—approximately the weight of eight aircraft carriers—to create huge underground caverns for the assembly of enormous particle detectors, all to better understand the mysterious neutrino. DUNE was conceived, designed and will be built by a team of 1,000 scientists and engineers from more than 30 countries and 160 institutions, including UW–Madison.

In fact, when DUNE is operational years from now, it will rely on anode panel assemblies (APAs) built at the Stoughton UW laboratory.

The detectors will be made up of large panels (the APAs) that will be submerged in liquid argon. The APAs consist of ultrathin wires wound around metal. Each assembly created at the UW's PSL consists of a stainless steel frame that is 20 feet long, a layer of copper mesh, and almost 15 miles of very thin (150 micron diameter) copper beryllium wire wound around it in four layers. The wire is then attached to a circuit board to track neutrinos.

Overseeing PSL's work on DUNE is the lab's director, Bob Paulos. "The APAs are really the heart of the detector," Paulos says...