Enhanced Ion Acceleration in Wire Array Targets*

Laser-accelerated ion sources are relevant to applications requiring localized heat deposition, ranging from fast-ignition fusion to cancer therapy. A variety of techniques for ion acceleration have been proposed in literature in pursuit of obtaining higher ion energy and flux. Target-normal sheath acceleration (TNSA) remains a reliable and robust acceleration method that benefits from increased laser absorption [1]. Structuring the surface of a target with micron-sized wires enables >90% laser absorption, greatly enhancing the TNSA process. Additionally, the wires support surface plasma waves which generate a large dose of super-pondermotive electrons that in turn drive ions to high energies. The surface wave mechanism is explored and optimized using particle-in-cell simulations. The resulting wire array target can efficiently convert laser energy into a high-flux, energetic ion beam using currently available laser technology.

 

[1] Mora P. “Plasma expansion into a vacuum” Physical Review Letters 90.18 (2003): 185002.