Energetic Proton Generation in Ultra-Intense Laser-Solid Interactions

Wilks, S.C. ; Langdon, A.B. ; Cowan, T.E. ; Roth, M. ; Singh, M. ; Hatchett, S. ; Key, M.H. ; Pennington, D. ; MacKinnon, A. ; Snavely, R.A.

Lawrence Livermore National Laboratory

关键词: Bremsstrahlung;    Protons;    08 Hydrogen;    Targets;    Electrons;   

DOI  :  10.2172/793448
RP-ID  :  UCRL-ID-137814
RP-ID  :  W-7405-Eng-W
RP-ID  :  793448

美国|英语

来源: UNT Digital Library

【 摘 要 】

An explanation for the energetic ions observed in the PetaWatt experiments is presented. In solid target experiments with focused intensities exceeding 10{sup 20} W/cm{sup 2}, high-energy electron generation, hard bremsstrahlung, and energetic protons have been observed on the backside of the target. In this report, we attempt to explain the physical process present that will explain the presence of these energetic protons, as well as explain the number, energy, and angular spread of the protons observed in experiment. In particular, we hypothesize that hot electrons produced on the front of the target are sent through to the back off the target, where they ionize the hydrogen layer there. These ions are then accelerated by the hot electron cloud, to tens of MeV energies in distances of order tens of microns, whereupon they end up being detected in the radiographic and spectrographic detectors.