Ion Generation via Interaction between Intense Ultra-Short Laser Pulse and Solid Target for Application to Cancer Therapy

摘要

We started a project to develop a very compact accelerator for cancer therapy. To reduce the size of the system, we adopted a laser plasma ion source using a compact ultra-high intensity laser. We have performed ion generation experiments in which laser parameters were as follows: The wave length and the pulse duration were 800nm and 50fs, respectively. Peak power was 4-5TW. The laser pulse with normal incidence angle to the target was focused onto the target with 15 μm diameter giving power density of 3-4x10~(18)W/cm~2. Target foils were metals (Ti, Al) and plastics (polypropylene, polyethylene) with the thicknesses of 4-100 μm. We found that the angular distribution of ions with an energy of ～0.1MeV had a significant peak in the backward and forward in respect to the laser incidence direction.