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

Journal Article · Mon Sep 15 00:00:00 EDT 2014 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4896338· OSTI ID:22303442

Su, L. N.; Hu, Z. D.; Zheng, Y.; Liu, M.; Wang, W. M.; Shen, Z. W.; Fan, H. T.; Chen, L. M.; Lu, X.; Ma, J. L.; Wang, X.; Wang, Z. H.; Wei, Z. Y. ^[1]; Sheng, Z. M. ^[2]; Yuan, X. H.; Xu, M. H. ^[3]

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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. Department of Physics, China University of Mining and Technology (Beijing), Beijing 100083 (China)

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.

• OSTI ID: 22303442
• Journal Information: Physics of Plasmas, Vol. 21, Issue 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALUMINIUM
ENERGY SPECTRA
FOILS
KEV RANGE 100-1000
LASERS
PEAKS
PROTON BEAMS
PROTONS
PULSES
SAPPHIRE
SIMULATION
SURFACES