image: Conceptual illustration of micronozzle acceleration (MNA). A solid hydrogen rod is embedded in an aluminum micronozzle, which channels and focuses plasma flow to optimize proton acceleration.
Credit: Masakatsu Murakami
Osaka, Japan - Proton beams with giga-electron-volt (GeV) energies—once thought to be achievable only with massive particle accelerators—may soon be generated in compact setups thanks to a breakthrough by researchers at The University of Osaka.
A team led by Professor Masakatsu Murakami has developed a novel concept called micronozzle acceleration (MNA). By designing a microtarget with tiny nozzle-like features and irradiating it with ultraintense, ultrashort laser pulses, the team successfully demonstrated—through advanced numerical simulations—the generation of high-quality, GeV-class proton beams: a world-first achievement.
Unlike traditional laser-based acceleration methods that use flat targets and reach energy limits below 100 mega-electron-volt (MeV) (1 GeV = 1000 MeV), the micronozzle structure enables sustained, stepwise acceleration of protons within a powerful quasi-static electric field created inside the target. This new mechanism allows proton energies to exceed 1 GeV, with excellent beam quality and stability.
“This discovery opens a new door for compact, high-efficiency particle acceleration,” says Prof. Murakami. “We believe this method has the potential to revolutionize fields such as laser fusion energy, advanced radiotherapy, and even laboratory-scale astrophysics.”
The implications are wide-reaching:
- Energy: Supports fast ignition schemes in laser-driven nuclear fusion.
- Medicine: Enables more compact and precise systems for proton cancer therapy.
- Fundamental Science: Creates conditions to simulate extreme astrophysical environments and probe matter under ultra-strong magnetic fields.
The study, based on simulations performed on the SQUID supercomputer at The University of Osaka, marks the first-ever theoretical demonstration of compact GeV proton acceleration using microstructured targets.
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The article, “Generation of giga-electron-volt proton beams by micronozzle acceleration,” was published in Scientific Reports at DOI: https://doi.org/10.1038/s41598-025-03385-x
About The University of Osaka
The University of Osaka was founded in 1931 as one of the seven imperial universities of Japan and is now one of Japan's leading comprehensive universities with a broad disciplinary spectrum. This strength is coupled with a singular drive for innovation that extends throughout the scientific process, from fundamental research to the creation of applied technology with positive economic impacts. Its commitment to innovation has been recognized in Japan and around the world, being named Japan's most innovative university in 2015 (Reuters 2015 Top 100) and one of the most innovative institutions in the world in 2017 (Innovative Universities and the Nature Index Innovation 2017). Now, Osaka University is leveraging its role as a Designated National University Corporation selected by the Ministry of Education, Culture, Sports, Science and Technology to contribute to innovation for human welfare, sustainable development of society, and social transformation.
Website: https://resou.osaka-u.ac.jp/en
Journal
Scientific Reports
Method of Research
Computational simulation/modeling
Subject of Research
Not applicable
Article Title
Generation of giga-electron-volt proton beams by micronozzle acceleration
Article Publication Date
31-May-2025