Three-dimensional Imaging of Nanoplasma by Ion Nanoscopy

Abstract

The remarkable abilities of laser-irradiated nanostructures to emit X-ray photons, accelerate charged particles, and launch shock waves for multiple applications are primarily governed by a localized plasma near the surface. However, the full-spatially resolving the localized plasma is still challenging due to the difficulty of measuring the three-dimensional (3D) momentum of ions generated from partially or fully ablated nanostructures in high-intensity laser fields. Here, we bridge this gap by introducing ion nanoscopy based on the tomographic reconstruction of the 3D momentum of ions emitted from constantly refreshed aerosolized TiO2 nanospheres. The measured 3D ion momenta map the localized plasma charge well through an electrostatic repulsion model. A pronounced variation in localized plasma charge across the nanosphere surface is obtained, which also extends the idea of the combined action of external and internal fields on plasma formation. This work represents an advance in understanding plasma generation from nanostructures and in the probing, visualization, and manipulation of localized nanoplasmas.