Breakthrough in laser-induced electromagnetic pulses: new study reveals key mechanisms and control methods

Researchers from PKU, CAEP, SJTU, and UESTC have unveiled findings on the generation and regulation of electromagnetic pulses (EMPs) produced by multi-petawatt lasers interacting with nitrogen gas jets. Published in a comprehensive study, their work demonstrates how EMP characteristics can be tuned by adjusting laser energy and gas jet pressure, paving the way for controlled EMP applications in scientific and industrial fields.

Key Findings and Innovations

The study reveals that EMP intensity is directly correlated with the quantity and energy of electrons accelerated by the plasma channel formed during laser-gas jet interactions. By varying nitrogen gas jet pressure (1–3.15 MPa) and laser energy (16–48 J), the team observed peak EMP amplitude at 2.15 MPa, beyond which intensity declined due to energy loss in plasma channel boundaries.

Notably, the research identifies four primary EMP sources:

1. Transient currents from escaping electrons.
2. Neutralization currents induced by positively charged gas targets.
3. Surface currents on metallic conductors within the experimental chamber.
4. Electron collisions with target chamber walls.

Implications for Industry and Research

The ability to control EMPs through laser and gas jet parameters holds promise for:

1. High-Power Microwave Sources: Enabling precise EMP generation for advanced communication and radar technologies.
2. Non-Destructive Testing: Utilizing EMPs for material inspection without physical contact.
3. Nuclear Safety and Diagnostics: Mitigating EMP interference in high-energy laser experiments.

The complete study is accessible via DOI: 10.1007/s41365-025-01692-6