Controllable Laser Ion Acceleration

In this paper a future laser ion accelerator_x1048577_ is discussed to make the laser-based ion accelerator compact and controllable. Especially a collimation device is focused in this paper. The future laser ion accelerator should have an ion source, ion collimators, ion_x1048577_ beam bunchers, and ion post acceleration devices [Laser Therapy 22, 103(2013)]: the ion particle energy and the ion energy spectrum are controlled to meet requirements for a future compact laser ion_x1048577_ accelerator for ion cancer therapy or for other purposes. The energy efficiency from the laser to ions is improved by using a_x1048577_ solid target with a fine sub-wavelength structure or_x1048577_ a near-critical density gas plasma. The ion beam_x1048577_ collimation is performed by holes behind the solid_x1048577_ target or a multi-layered solid target. The control _x1048577_ of the ion energy spectrum and the ion particle energy, and the ion beam bunching would be successfully_x1048577_ realized by a multistage laser-target interaction.