The international neutrino physics community has come together to develop the Deep Underground Neutrino Experiment (DUNE), a leading-edge experiment for neutrino science and proton decay studies. This experiment, together with the facility that will support it, the Long-Baseline Neutrino Facility, an internationally designed, coordinated and funded program, hosted at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois. DUNE represents the convergence of several formerly independent worldwide efforts around the opportunity provided by the megawatt neutrino beam facility planned at Fermilab and by the new significant expansion at the Sanford Underground Research Facility (Sanford Lab). DUNE will develop detectors to install at both sites, a fine-grained near neutrino detector to be installed 600 m downstream of the Fermilab beamline, and a 40,000 metric ton cryogenic liquid argon detector deployed deep underground at Sanford Lab, located 800 miles (1,300 km) downstream in Lead, South Dakota.
The primary DUNE activity at LANL is the development and management of the near detector systems. Two measurements will be made at the near site. First, the muons that penetrate the absorber will be characterized to give a spill-by-spill record of the profile of the beam and to constrain the neutrino fluxes. Next, detailed measurements of neutrino interactions will be made to constrain the fluxes, interaction modes, and event topologies.
The high-statistics neutrino scattering data will allow for many cross-section measurements and precision tests of the standard model. While reducing the uncertainties on the long-baseline oscillation analyses are their primary mission, the near detectors enable searches for physics beyond the standard model as well as measurements of processes important for systematic uncertainty reduction in the study of atmospheric neutrinos and searches for nucleon decay at the far site.
The muon detectors are shown in Figure 1. There are three sets of detectors. The ionization chambers measure the spill-by-spill profile of the beam. The threshold Cherenkov detectors measure all muons above a variable threshold to constrain the neutrino spectrum. The Stopped Muon counters measure muons that stop after a certain thickness of absorbing material, thereby selecting muons above a certain energy. This constrains the neutrino spectrum. The Stopped Muon counters measure negative and positively charged muons separately, allowing separate constraints for muon neutrino and anti-neutrino spectra.
Figure 2 shows LANL staff member Geoff Mills with a prototype for the threshold Cherenkov detector. The prototype has now been installed in the NuMI beamline for testing.
Two neutrino detectors have been envisioned. The first is a high precision tracking detector based on strawtubes and shown in Figure 3. The second is a magnetized liquid argon time-projection chamber shown in Figure 4.
In addition to the near detector effort, LANL is responsible for far detector calibration. The focus now is on deploying a laser system to create tracks of ionization with well-known position. A prototype will be deployed into the CAPTAIN detector.
There is a strong team of LANL staff members working on DUNE. The near detector effort is led by LANL staff members in the Subatomic Physics Group (P-25), while the far detector calibration effort is led by staff members in the Neutrons and Weak Interactions Group (P-23) and in the P-27 group.
Staff Scientists and Postdoctoral Scholars:
- Gerald Garvey
- Elena Guardincerri
- Qiuguang Liu
- William Louis
- Christopher Mauger
- Geoff Mills
- Keith Rielage
- Gus Sinnis
- Charles Taylor
- Richard Van de Water