HIAF

HIAF. The High Intensity heavy-ion Accelerator Facility is a major national scientific infrastructure project in China, designed as a next-generation facility for research in nuclear physics, atomic physics, and related interdisciplinary fields. Located at the Huizhou campus of the Institute of Modern Physics under the Chinese Academy of Sciences, its primary purpose is to generate intense beams of stable and radioactive ions to explore the limits of nuclear existence and the properties of nuclear matter under extreme conditions. The facility represents a significant leap forward in China's capabilities in accelerator-based science, aiming to produce world-leading research on the origin of chemical elements and the evolution of astrophysical objects like neutron stars.

Overview

HIAF is conceived as a flagship facility within China's strategic plan for advancing fundamental science, positioned to maintain the nation's competitiveness in areas pioneered by institutions like GSI Helmholtz Centre for Heavy Ion Research and the Facility for Rare Isotope Beams. Its core mission is to push the frontiers of knowledge concerning the strong interaction, the fundamental force that binds protons and neutrons within atomic nuclei. By providing unprecedented beam intensities, particularly for rare isotopes far from stability, HIAF will enable scientists to conduct experiments that were previously impossible, such as detailed studies of nucleosynthesis processes that occur in violent stellar explosions like supernovae and neutron star mergers. The project underscores a long-term commitment by the Chinese government and the scientific community to build and operate large-scale research infrastructures.

Technical specifications

The accelerator complex is based on a sophisticated, multi-stage design that begins with two high-performance electron cyclotron resonance ion sources capable of producing highly charged ions. These beams are then injected into a linear accelerator for initial acceleration before being transferred to a booster synchrotron, which ramps up their energy. The heart of HIAF is a large-acceptance, multi-purpose storage ring known as the Spectrometer Ring, which can operate as a cooler-storage ring for high-precision mass and lifetime measurements of short-lived nuclei. Key parameters include design goals for producing uranium beams at energies up to 1 GeV per nucleon and achieving extremely high beam intensities, with a production target for rare isotopes that surpasses current capabilities at facilities like the RIKEN Radioactive Isotope Beam Factory in many areas.

Scientific goals and research programs

The research portfolio at HIAF is broad and ambitious, centered on several flagship experimental programs. A primary goal is the systematic study of the nuclear chart towards the so-called drip lines, where nuclei become unbound, to test and refine theoretical models like density functional theory and lattice QCD calculations. Another major program focuses on investigating the properties of nuclear matter at high baryon density, relevant to understanding the interior structure of compact stars observed by observatories like LIGO and Virgo interferometer. Furthermore, HIAF will host experiments in atomic physics with highly charged ions, research into nuclear astrophysics reaction rates, and applied studies in materials science and radiobiology using its intense radiation fields.

Development and construction

The project was formally initiated following its approval by the National Development and Reform Commission of China as part of the 13th Five-Year Plan. The conceptual design was developed by a large team of scientists and engineers at the Institute of Modern Physics, building upon decades of experience from operating the Heavy Ion Research Facility in Lanzhou and contributing to international projects like the FAIR facility at GSI. Major construction commenced at the selected greenfield site in Huizhou, with significant milestones including the completion of civil engineering for the main tunnels and the installation of key components such as the first superconducting magnet prototypes. The project timeline aims for the commencement of commissioning with first beams in the late 2020s.

International collaboration

HIAF is being developed as an open international user facility, following the model of major global laboratories like CERN and KEK. The project has actively sought and established cooperative agreements with numerous research institutions worldwide, including GSI Helmholtz Centre for Heavy Ion Research in Germany, the Joint Institute for Nuclear Research in Dubna, and universities across Europe, North America, and Asia. These collaborations involve joint development of critical detector systems, such as advanced gamma-ray spectrometer arrays and time-projection chambers, as well as theoretical support and planning for future experimental campaigns. This global engagement is intended to pool scientific expertise and ensure HIAF achieves its maximum potential impact on the international nuclear physics community.

Category:Particle accelerators Category:Nuclear physics research facilities Category:Scientific infrastructure in China