Radiation pressure acceleration of protons to 93 MeV with circularly polarized petawatt laser pulses

• Published in: Physics of plasmas 2016-07, Vol.23 (7)
• Main Authors: Kim, I. Jong, Pae, Ki Hong, Choi, Il Woo, Lee, Chang-Lyoul, Kim, Hyung Taek, Singhal, Himanshu, Sung, Jae Hee, Lee, Seong Ku, Lee, Hwang Woon, Nickles, Peter V., Jeong, Tae Moon, Kim, Chul Min, Nam, Chang Hee
• Format: Article
• Language: English
• Subjects: Acceleration; Charged particles; Circular polarization; Dependence; Ion beams; Ion sources; Laser beams; Lasers; Particle beams; Particle in cell technique; Proton beams; Radiation pressure; Target thickness
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.4958654

The radiation pressure acceleration (RPA) of charged particles has been a challenging task in laser-driven proton/ion acceleration due to its stringent requirements in laser and target conditions. The realization of radiation-pressure-driven proton acceleration requires irradiating ultrathin targets with an ultrahigh contrast and ultraintense laser pulses. We report the generation of 93-MeV proton beams achieved by applying 800-nm 30-fs circularly polarized laser pulses with an intensity of 6.1 × 10 20   W / cm 2 to 15-nm-thick polymer targets. The radiation pressure acceleration was confirmed from the obtained optimal target thickness, quadratic energy scaling, polarization dependence, and three-dimensional particle-in-cell simulations. We expect this clear demonstration of RPA to facilitate the realization of laser-driven proton/ion sources delivering energetic and short-pulse particle beams for novel applications.