China's HIAF Completes Construction, Begins Trial Operations

China's High Intensity Heavy-ion Accelerator Facility (HIAF) has completed construction. This national project recently passed its technological acceptance review, commencing trial operations. Located in Huizhou, Guangdong Province, HIAF is a development for heavy-ion physics and its applications. It was developed by the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS).

Credits: IMP

Heavy-ion accelerators are instruments for scientific exploration, allowing researchers to investigate fundamental interactions, the structure of matter, and the universe's evolution. Progress in these facilities improved scientific understanding and contributed to broad technological applications. The pursuit of ultra-microscopic and extreme conditions makes high-intensity, high-performance heavy-ion accelerators critical for nuclear science advancement.

The HIAF project, proposed by IMP in 2009, commenced construction in Dec. 2018. In Oct. 2025, after seven years, the facility completed its first comprehensive beam commissioning. And the facility spans approximately 32.4 hectares, with a two-kilometre beamline 13 metres underground. It integrates a superconducting linear accelerator with a fast-cycling synchrotron, making it the world's first advanced heavy-ion research facility. HIAF is engineered to produce the world's most intense pulsed heavy-ion beams, with energies from MeV/u to GeV/u.

Prof. YANG Jiancheng, IMP deputy director and chief engineer for HIAF, stated that high intensity is the key indicator for next-generation ion accelerators. This means a substantial increase in ions accelerated per pulse. He noted that achieving this ultra-high intensity presented considerable technical challenges, with development spanning over a decade.

HIAF incorporates several innovations, including ultra-fast ramping power supplies capable of altering current by thousands of amperes within 100 milliseconds. A magnetic field ramping rate of 12 T/s is achieved. A high-precision radiofrequency system delivers an electric field strength of around 35 kV/m. But the facility also maintains an ultra-clean internal environment within a thin-walled, 0.3 mm thick titanium alloy-lined chamber, achieving a vacuum pressure of 10-12 mbar, comparable to the vacuum on the Moon.

These technological advancements enabled HIAF to demonstrate beam performance exceeding design specifications. During commissioning, the facility achieved an intensity of 2.5 × 10¹¹ particles per pulse for oxygen ion beams and 3.2 × 10¹⁰ particles per pulse for bismuth ions. These figures set new world records for beam intensity among similar heavy-ion accelerator facilities, indicating its capabilities.

HIAF accelerates a wide spectrum of ion species, from hydrogen to uranium, producing thousands of unstable atomic nuclei; this places it among a select group of global accelerators. So the facility focuses on three primary scientific objectives: exploring nuclear existence limits, deciphering nuclear astrophysics processes, and furthering interdisciplinary heavy-ion applications. Six experimental terminals are included, such as the Spectrometer Ring, the Gas-filled Recoil Achromatic Solenoid Spectrometer, and the High-Rigidity Radioactive Ion Beam Line.

Commissioning experiments at HIAF yielded notable results. Researchers achieved a mass accuracy for the short-lived nuclide Au-202 twice as precise as the previous global record, and identified two new isotopes. These findings indicate the facility's combined strengths in high intensity, high energy, and high precision beams for experimental work, pushing scientific understanding.

HIAF will function as an international scientific user facility. Prof. YANG stated HIAF is expected to become a significant global heavy-ion research centre. Scientists from universities, research institutes, and industries worldwide are invited to collaborate and conduct experiments there. And this aims to foster broader scientific cooperation.

The facility is projected to support global scientists in advancing nuclear physics, nuclear astrophysics, and atomic physics research. It will also assist with heavy-ion beam applications in various fields, including healthcare, materials science, and biological breeding. Work at HIAF could therefore have implications across scientific and industrial sectors.

• HIAF has completed construction and commenced trial operations in Huizhou, Guangdong Province.

• The facility, developed by IMP, achieved new world records for heavy-ion beam intensity.

• It integrates a superconducting linear accelerator with a fast-cycling synchrotron, a global first.

• HIAF will operate as an international scientific user facility for advanced research.

• Its applications span nuclear physics, astrophysics, atomic physics, healthcare, materials science, and biological breeding.

Source: IMP News