Eliasson, Bengt and Liu, Chuan S. and Shao, Xi and Sagdeev, Roald Z. and Shukla, Padma K. (2009) Laser acceleration of monoenergetic protons via a double layer emerging from an ultra-thin foil. New Journal of Physics, 11 (7). ISSN 1367-2630
1367_2630_11_7_073006.pdf - Published Version
Available under License Creative Commons Attribution.
We present theoretical and numerical studies of the acceleration of monoenergetic protons in a double layer formed by the laser irradiation of an ultra-thin film. The ponderomotive force of the laser light pushes the electrons forward, and the induced space charge electric field pulls the ions and makes the thin foil accelerate as a whole. The ions trapped by the combined electric field and inertial force in the accelerated frame, together with the electrons trapped in the well of the ponderomotive and ion electric field, form a stable double layer. The trapped ions are accelerated to monoenergetic energies up to 100 MeV and beyond, making them suitable for cancer treatment. We present an analytic theory for the laser-accelerated ion energy and for the amount of trapped ions as functions of the laser intensity, foil thickness and the plasma number density. We also discuss the underlying physics of the trapped and untrapped ions in a double layer. The analytical results are compared with those obtained from direct Vlasov simulations of the fully nonlinear electron and ion dynamics that is controlled by the laser light.
|Keywords:||plasma interactions, electron-beams, wakefield accelerator, fusion ignition, ion-beams, driven, pulses, generation, radiation, therapy, Physics, Physics and Astronomy(all)|
|Subjects:||Science > Physics|
|Department:||Faculty of Science > Physics|
|Depositing user:||Strathprints Administrator|
|Date Deposited:||08 Jun 2010 08:34|
|Last modified:||04 May 2016 16:15|