IREN

IREN. The IREN facility is a high-intensity pulsed neutron source based on a linear electron accelerator, constructed at the Joint Institute for Nuclear Research in Dubna. Its primary purpose is to generate intense beams of neutrons for fundamental research in nuclear physics and applied studies in condensed matter physics. The installation represents a significant advancement in the infrastructure for neutron research within the Commonwealth of Independent States.

Overview

IREN, which stands for IBR-2M Reactor Replacement, was conceived as a modern successor to the renowned IBR-2 pulsed fast reactor. Located within the Frank Laboratory of Neutron Physics, the facility is designed to produce neutrons through the process of bremsstrahlung and subsequent photonuclear reactions, a method distinct from traditional nuclear reactors. This approach allows for precise control over the neutron pulse timing and energy spectrum. The project aims to provide the international scientific community with a powerful tool for neutron scattering experiments, nuclear data measurements, and investigations into the structure of atomic nuclei.

History

The conceptual design for IREN was developed in the early 2000s, following decades of successful operation of the IBR-2 reactor. Formal construction began in 2009 at the Joint Institute for Nuclear Research, an institution historically prominent for discoveries like that of synthetic elements. Key figures in its development included physicists from the Frank Laboratory of Neutron Physics and collaborators across the Member states of the Joint Institute for Nuclear Research. The first beam was achieved in 2014, marking a major milestone. The facility's commissioning and gradual ramp-up of operational parameters occurred throughout the late 2010s, positioning it as a central part of the Seven-Year Plan for JINR Development.

Scientific objectives and research

The core scientific program at IREN encompasses a wide range of interdisciplinary studies. In fundamental nuclear physics, experiments focus on measuring neutron cross-sections, studying properties of neutron-rich nuclei, and investigating processes like neutron-induced fission. For materials science, the neutron beams are used in small-angle neutron scattering and neutron diffraction to probe the structure of novel materials, including high-temperature superconductors and complex magnetic systems. Additional research avenues include radiography for industrial applications, studies in solid-state physics, and fundamental tests in neutron optics.

Technical specifications

The IREN facility is centered on a linear electron accelerator (linac) capable of producing an electron beam with an energy of up to 200 MeV and an average current of 10 milliamperes. This beam is directed onto a heavy-metal tantalum or uranium target, generating gamma rays which then produce neutrons via (γ,n) reactions. The design yields a peak neutron flux exceeding 10¹⁵ neutrons per second per square centimeter, with pulse durations variable from microseconds to milliseconds. The complex includes multiple experimental stations, such as the VERTEX spectrometer for nuclear physics, and is equipped with advanced detector systems like germanium detectors and scintillation counters.

International collaboration and management

IREN operates as a major international research facility under the umbrella of the Joint Institute for Nuclear Research. Member states such as Russia, Poland, Czech Republic, Romania, and Bulgaria play active roles in its scientific committees and experimental programs. Collaboration extends to other global neutron centers, including the Institut Laue-Langevin, the Spallation Neutron Source, and the European Spallation Source. The facility is managed by the Frank Laboratory of Neutron Physics, with oversight from the JINR Scientific Council. Its user program attracts scientists from institutions worldwide, including CERN, Los Alamos National Laboratory, and various European Union research networks.

Category:Research institutes Category:Neutron facilities Category:Joint Institute for Nuclear Research