# Topological approach for laser acceleration investigation

## TL;DR

This paper introduces a topological approach to understanding laser particle acceleration, classifying acceleration schemes based on target shape deformation, and identifying conditions for high-energy ion generation.

## Contribution

It applies topological analysis to classify laser ion acceleration schemes and reveals the impact of target shape deformation on ion energy efficiency.

## Key findings

- High-energy ions are produced when target deformation is non-homeomorphic.
- Target thickness significantly influences ion energy in non-homeomorphic cases.
- Ion energy is lower and less affected by thickness when deformation is homeomorphic.

## Abstract

An approach using topology reveals a new understanding and knowledge of laser particle acceleration. Laser pulse irradiation on a thin-foil target is examined using two-dimensional particle-in-cell simulations. Through topology, laser ion acceleration schemes are classified depending on whether the deformed target shape after laser irradiation is homeomorphic with respect to the initial target. High energy ions are generated with high-efficiency when the deformed target shape is non-homeomorphic. In this case, the target thickness greatly affects the obtained ion energy. However, when the deformed target shape is homeomorphic, the obtained ion energy is low, and the effect of the target thickness is small.