Osaka, Japan – A research team at the University of Osaka has introduced a groundbreaking approach to generating ultrahigh magnetic fields using a technique known as bladed microtube implosion (BMI). By leveraging laser-driven implosions of specially structured microtubes, the team has demonstrated the potential to reach magnetic field strengths nearing one megatesla—a remarkable leap in compact plasma science.

These extreme fields, theoretically comparable to those observed near highly magnetized neutron stars and astrophysical jets, are created using a compact experimental setup. The project, led by Professor Masakatsu Murakami, proposes the use of micron-scale hollow cylinders equipped with internal blade-like structures. When hit with ultra-intense, femtosecond laser pulses, the blades induce swirling, asymmetric plasma motion that generates strong circulating currents.

As these currents form near the tube’s center, they naturally produce a powerful axial magnetic field. This self-generated loop current reaches values above 500 kilotesla, bringing researchers closer to the megatesla threshold. Notably, the process does not require any externally applied magnetic field.

A New Mechanism for High-Field Generation

Unlike traditional magnetic compression methods that amplify a pre-existing field, BMI enables field creation from scratch through laser-plasma interactions. The key lies in the design of the microtube: asymmetry within the structure causes plasma to swirl and generate magnetic fields independently. As the plasma flows tighten and accelerate, a feedback loop emerges—charged particles (ions and electrons) amplify the magnetic field, which in turn further confines those particles.

“This approach offers a powerful new way to create and study extreme magnetic fields in a compact format,” says Prof. Murakami. “It provides an experimental bridge between laboratory plasmas and the astrophysical universe.”

The implications of this research are far-reaching. Potential applications include:

• Laboratory astrophysics: simulating magnetized jets and stellar interiors
  
• Laser fusion: advancing proton-beam fast ignition techniques
  
• High-field quantum electrodynamics (QED): enabling exploration of non-linear quantum phenomena
  

The research team conducted detailed simulations using the fully relativistic EPOCH code on the SQUID supercomputer at The University of Osaka. They also developed a complementary analytical model to better understand the underlying scaling laws and optimize target design.

About The University of Osaka
Founded in 1931 as one of Japan’s seven imperial universities, The University of Osaka is now among the country’s top-tier comprehensive institutions. It integrates broad scientific disciplines with a strong focus on innovation, ranging from fundamental research to practical technologies with global impact. As a Designated National University Corporation, Osaka University is committed to fostering innovation for human welfare, sustainable development, and societal transformation.

Original Publication
Authors: D. Pan and M. Murakami.
Journal: Physics of Plasmas
DOI: 10.1063/5.0275006
Method of Research: Computational simulation/modeling
Subject of Research: Not applicable
Article Title: Gigagauss magnetic field generation by bladed microtube implosion
Article Publication Date: 14-Jul-2025

Original Source: https://resou.osaka-u.ac.jp/en