ProtoDUNE

ProtoDUNE
Name	ProtoDUNE
Location	CERN, Geneva
Project	Deep Underground Neutrino Experiment
Detector type	Liquid argon time projection chamber
Collaboration	CERN, Fermilab, University of Oxford, INFN
Start	2018
Status	Commissioned

ProtoDUNE ProtoDUNE was a large-scale prototype experiment built at CERN in Geneva to validate detector technologies for the Deep Underground Neutrino Experiment and to study detector response to test beams. The project brought together collaborations from institutions such as Fermilab, University of Oxford, INFN, CERN Neutrino Platform, and national laboratories to prototype Liquid Argon Time Projection Chamber techniques and cryogenic systems. ProtoDUNE operated in the context of international efforts including the Long-Baseline Neutrino Facility and contributed to the technical design of the full-scale DUNE far detectors.

Overview

ProtoDUNE comprised two separate demonstrators constructed in the CERN Neutrino Platform test beam area: one based on single-phase liquid argon time projection chamber technology and another using dual-phase readout concepts. The initiative linked expertise from Fermilab, LBNF, DUNE collaboration, CERN, University of Oxford, ETH Zurich, Imperial College London, and INFN groups to assess performance, scalability, and maintainability for multi-kiloton modules. ProtoDUNE addressed issues relevant to the DUNE Technical Design Report, Neutrino oscillation systematics, supernova neutrinos, and proton decay sensitivity studies.

Design and Detector Technology

The single-phase detector implemented a time projection chamber with high-voltage cathode planes, anode plane assemblies, and cold electronics developed by teams from Fermilab, CERN, Brookhaven National Laboratory, SLAC National Accelerator Laboratory, and CEA Saclay. The dual-phase demonstrator incorporated large electron multipliers and extraction grids with contributions from ETH Zurich, CNRS, University of Bern, and IFIC. Cryostat design used membrane cryostat technology derived from industrial LNG practice and collaborations with GTT (Gaztransport & Technigaz), while cryogenics and argon purification systems involved CERN Technical Department, INFN Padova, and University of Manchester. Readout electronics, data acquisition, and trigger systems integrated hardware and firmware developed at Fermilab, CERN Data Centre, University of Sheffield, and University of Wisconsin–Madison.

Construction and Commissioning

Construction took place in the EHN1 test beam hall with civil, cryogenic, and detector assembly coordinated by CERN engineers, technicians from Fermilab, and international university groups. Component fabrication occurred at partner labs including Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, TRIUMF, and University of California, Berkeley. Commissioning required cryogenic cooldown, high-voltage conditioning, wire-plane and anode validation, and beamline integration with PS (Proton Synchrotron) tests and the CERN SPS test beam. Safety reviews and project management followed procedures from CERN safety rules and governance models used by the European Strategy for Particle Physics.

Experimental Program and Data Taking

ProtoDUNE exposed the detectors to charged-particle beams delivered by the CERN SPS to measure detector response to electrons, pions, muons, and protons across a range of energies. The experimental program included calibration campaigns using cosmic-ray muons, laser systems, and radioactive sources, with analysis work performed by groups from Fermilab, University of Oxford, ETH Zurich, Università di Pisa, University of Manchester, and University of Bern. Data acquisition campaigns were coordinated with the CERN Neutrino Platform and used distributed computing resources at the Worldwide LHC Computing Grid and national grids such as GridPP and OSG. Software frameworks and reconstruction algorithms employed tools from LArSoft, Gaudi, ROOT, and machine-learning efforts from CERN openlab partners.

Results and Performance

ProtoDUNE achieved key milestones including demonstration of long drift operation, argon purity compatible with DUNE requirements, and successful reconstruction of test-beam particle interactions. Performance metrics such as electron lifetime, signal-to-noise ratio, spatial resolution, and calorimetric energy reconstruction were validated by analyses led by teams at Fermilab, Imperial College London, University of Oxford, ETH Zurich, and INFN. Results informed background rejection strategies for neutrino oscillation measurements and improved models used in GENIE neutrino interaction simulations. Publications and conference presentations at venues like Neutrino 2018, ICHEP, and EPS-HEP disseminated findings to the particle physics community.

Implications for DUNE and Future Work

ProtoDUNE provided direct input to the DUNE Technical Design Report and influenced choices for far detector module technologies, cryostat implementation, and quality assurance protocols used by LBNF/DUNE. Lessons learned impacted construction planning at the Sanford Underground Research Facility, coordination with Fermilab for module assembly, and selection of cold electronics and photon detection systems. Ongoing analysis continues to refine reconstruction, calibration, and systematic uncertainty estimates relevant for long-baseline measurements involving the Long-Baseline Neutrino Facility and for searches for supernova neutrino bursts and proton decay. Follow-on prototypes and test programs are being pursued by collaborations including DUNE collaboration institutions and national laboratories to finalize designs for multi-kiloton detectors.

Category:Neutrino experiments Category:CERN experiments