Adapted from the CERN Courier’s article of July 8, 2016 “Neutrinos take center stage.” Read full article. Also see the related article “NOvA releases new bounds on neutrino mixing parameters.“
CERN has a long tradition in neutrino physics. The Gargamelle detector at CERN provided the first evidence for the weak neutral current in 1973, and BEBC, CDHS and CHARM further unveiled the neutrino’s identity in the following years. Precise measurements at the Large Electron–Positron Collider in 1989 showed that there are three types of light neutrinos that couple to the Z boson. Searches for neutrino oscillations at NOMAD and CHORUS took place during the 1990s, and from 2006 to 2012, CERN sent a muon-neutrino beam to the ICARUS and OPERA detectors at the Gran Sasso National Laboratory. At the end of 2014, CERN inaugurated its Neutrino Platform with the aim of providing a focal point for Europe’s contributions to global neutrino research.
So far, around 50 European institutes have signed up as members of the Neutrino Platform where together with CERN staff they will develop and prototype the next generation of neutrino detectors. This represents a shift for CERN from its traditional role of providing neutrino beams to one where it shares its expertise in detectors, infrastructure and international collaboration.
“The Neutrino Platform pulls together a community that is scattered across the world and CERN has committed significant resources to support R&D in all aspects of neutrino research,” says project leader Marzio Nessi. “It provides a structure at CERN to foster active involvement of Europe and CERN in the U.S. and Japanese facilities.”
Currently the Neutrino Platform’s WA104 team is refurbishing the ICARUS detector. It will be shipped to Fermilab in 2017 to become part of a dedicated short-baseline neutrino (SBN) program there.
DUNE, a long-baseline experiment also hosted at Fermilab, will have a far detector consisting of four 10-kt active LArTPC modules located 1,300 km away. The modules are planned to be of two different designs, single-phase (which uses technology that is very similar to that in ICARUS) and dual-phase, in which ionization electrons are pulled into a gaseous Ar region above the liquid. To enable both types of LArTPC detectors to be scaled up to the multi-kiloton level required by DUNE, the Neutrino Platform is building two large-scale prototypes (called ProtoDUNEs), one of each design. The dual-phase ProtoDUNE is also known as WA105.
“The ProtoDUNE tests foreseen at the CERN Neutrino Platform represent the culmination of more than a decade of R&D towards the feasibility of very large liquid-argon time projection chambers for next-generation long-baseline experiments,” said André Rubbia, co-spokesperson of the DUNE collaboration.
The single- and dual-phase ProtoDUNEs are planned to be ready for test beam by 2018 at a new EHN1 test facility currently under construction in the north area of CERN’s Prévessin site. Most of the civil-engineering work to extend the EHN1 building is complete and all components are under procurement or installation, with staff expected to move in towards the end of this year. The test facility was financed by CERN, with two beamlines due to be commissioned in late 2017.
Complementing the detector hardware developments is work on reconstruction of LArTPC data, an area that still proves challenging. CERN is at the frontier, searching out the most advanced methods of computer visualizations and machine learning to extract physics information from the data.
The CERN Neutrino Platform is also working on components for Japan’s neutrino program and plans to involve a neutrino-theory working group to strengthen the connections between CERN and the worldwide community and help to promote research in theoretical neutrino physics at CERN.