- Featured in Physics
- Editors' Suggestion
Experimental Observation of Anomalous Stopping of Mega-ampere Electron Current in Porous Materials
Phys. Rev. Lett. 136, 185102 – Published 8 May, 2026
DOI: https://doi.org/10.1103/yq7c-8bsv
Abstract
Energy loss of fast electrons in materials is a fundamental process in many fields spanning fusion research, high-energy-density physics, astrophysics, and material science. Contrary to conventional collisional theory that predicts greater energy loss in denser materials, we experimentally observe an anomalous phenomenon: high-current-density electron beams undergo significantly stronger deflection and stopping in low-average-density porous foams than in their denser counterparts. Pore-resolved simulations and theoretical analysis demonstrate that return currents along the foam’s skeleton generate multi-kilo-Tesla magnetic fields in the vacuum pores. These intense fields strongly scatter beam electrons, enhancing stopping by orders of magnitude beyond collisional predictions. The derived conditions for this anomalous stopping agree with experiments and simulations, establishing a new microstructure-mediated regime of beam-matter interaction with potential applications in charged-beam control for fusion and laboratory astrophysics.
Physics Subject Headings (PhySH)
- Beam injection, extraction & transport
- Beam instabilities
- Collective behavior in networks
- High intensity beam dynamics
- High intensity laser-plasma interactions
- High-energy-density plasmas
- Laser-plasma interactions
- Nonlinear beam dynamics
- Nonlinear phenomena in plasmas
- Plasma instabilities
- Plasma interactions
- Plasma-beam interactions
- Plasma-particle interactions
- Transport in networks
Corrections
4 June, 2026
Correction: The equal contribution statement for the first two authors was presented incorrectly and has been fixed.
Focus
Void-Filled Material Stops Intense Electron Beam
An intense electron beam is stopped more efficiently by a highly porous material than by a less porous material, suggesting new strategies for controlling beams.
See more in Physics