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Title: Angle-dependent modulated spectral peaks of proton beams generated in ultrashort intense laser-solid interactions

Proton acceleration from 4 μm thick aluminum foils irradiated by 30-TW Ti:sapphire laser pulses is investigated using an angle-resolved proton energy spectrometer. We find that a modulated spectral peak at ∼0.82 MeV is presented at 2.5° off the target normal direction. The divergence angle of the modulated zone is 3.8°. Two-dimensional particle-in-cell simulations reveal that self-generated toroidal magnetic field at the rear surface of the target foil is responsible for the modulated spectral feature. The field deflects the low energy protons, resulting in the modulated energy spectrum with certain peaks.
Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;  [1] ;  [2] ;  [3] ; ;  [2] ;  [4]
  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
  2. Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)
  3. (United Kingdom)
  4. Department of Physics, China University of Mining and Technology (Beijing), Beijing 100083 (China)
Publication Date:
OSTI Identifier:
22303442
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALUMINIUM; ENERGY SPECTRA; FOILS; KEV RANGE 100-1000; LASERS; PEAKS; PROTON BEAMS; PROTONS; PULSES; SAPPHIRE; SIMULATION; SURFACES