Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Target Nano-particles size effect on the laser proton acceleration in the TNSA mechanism

Document Type : Research Paper

Authors

M.J. Jafari 1
E. Yazdani 2
S. Rezaei 2

1 Plasma and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, AEOI, P.O. Box: 14399-51113, Tehran, Iran

2 Department of Physics, Faculty of Basic Sciences, Tarbiat Modares University, P.O.Box: 14115-175, Tehran - Iran

https://doi.org/10.24200/nst.2020.1097
Abstract
One of the most common laser proton acceleration mechanism is Target Normal Sheath Acceleration (TNSA) method. The use of a foam layer in front of the main target plays an important role in the amount of laser energy absorption by the electrons and consequently the acceleration of the proton. The front layer can be either uniform and homogeneous or nano-structured. In this study, by assuming a nanostructured foam layer, and using two-dimensional particle simulations code, the effect of nanoparticle’s radius on the proton cut-off energy is investigated. Particles with radii of 10, 60 and 120 nm and random sizes in the range of 10 to 120 nm have been studied and simulated in a front layer with thickness of 10 and 20 μm with near-critical average density at laser intensity (I≈1020W/cm2). According to the results, in the case of thin foam layer, the differences of electron and consequently proton spectra are negligible. However, by increasing the foam thickness, the influence of nanoparticle radius causes a further dissociation in the final proton energy spectra. So that, the proton energy increases almost 45% by reducing the nanoparticle size from 120 nm to 10 nm.

Highlights

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2.         E. Clark, et al. Energetic heavy-ion and proton generation from ultraintense laser-plasma interactions with solids, Phys. Revi. Lett. 85(8), 1654 (2000).
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8.         D. Neely, et al. Enhanced proton beams from ultrathin targets driven by high contrast laser pulses, Appl. Phys. Lett. 89(2), 021502 (2006).
9.         D. Margarone, et al. Laser-driven proton acceleration enhancement by nanostructured foils,

Keywords

TNSA
Laser proton acceleration
Nano-structured target
Nano particle size
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2.         E. Clark, et al. Energetic heavy-ion and proton generation from ultraintense laser-plasma interactions with solids, Phys. Revi. Lett. 85(8), 1654 (2000).
3.         P. Poole, et al. Laser-driven ion acceleration via target normal sheath acceleration in the relativistic transparency regime, New J. Phys. 20(1), 013019 (2018).
4.         H. Daido, M. Nishiuchi, A.S. Pirozhkov, Review of laser-driven ion sources and their applications, Rep. Progr. Phys. 75(5), 056401 (2012).
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