Generation of a magnetic-field enhanced diffuse plume in an atmospheric pressure argon plasma jet

Atmospheric pressure plasma jet (APPJ) has the ability to emanates low-temperature plasma plumes suitable for material surface modification, particularly for three-dimensional objects. While helium-fed APPJ can readily produce diffuse plumes ideal for uniform treatment, argon-fed APPJ typically forms filamentary plumes that cause localized surface effects and potential damage. Achieving a stable, enhanced diffuse plume in argon APPJ remains challenging. This work demonstrates the realization of a diffuse argon plume using a pulsed APPJ enhanced by an axial magnetic field. The magnetic field (0–470 mT) confines the radial diffusion of electrons via Lorentz force, extending plasma plume propagation and intensifying reactive species generation. Diagnostics confirm significant improvements in plume length, emission intensity, and reactive species density for the diffuse argon plume.