摘要： We present a scheme to significantly increase the energy of quasi-monoenergetic protons accelerated by a laser beam without increasing the input power. This improvement is accomplished by first irradiating the foil several wave periods with circular polarization and then switching the laser to linear polarization. The polarization switch increases the electron temperature and thereby moves more electrons ahead of the proton layer, resulting in a space charge electric field pushing the protons forwards. The scaling of the proton energy evolution with respect to the switching time is studied, and an optimal switching time is obtained. The proton energy for the case with optimal switching time can reach about 80 MeV with an input laser power of 70 TW, an improvement of more than 30% compared to the case without polarization switch. 出版者： United States 出版日期： 2013-10-01 出處： Physics of plasmas, 2013-10, Vol.20 (10) 資源來源： AIP Journals (American Institute of Physics) 識別號： ISSN: 1070-664X 識別號： ISSN: 1527-2419 識別號： ISSN: 1089-7674 識別號： EISSN: 1089-7674 識別號： DOI: 10.1063/1.4826510
