Speaker
Xiaofei Shen
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.2022.pdf
Revisit of the Optimal Condition for Radiation Pressure Acceleration
X. F. Shen1 , B. Qiao1 , H. Zhang1,2 , S. Kar3 , C. T. Zhou1,2 , S. P. Zhu2 , M. Borghesi3 , X. T. He1,2
1 Center for Applied Physics and Technology, HEDPS, State Key Laboratory of Nuclear
Physics and Technology, and School of Physics, Peking University, Beijing, 100871, China
2 Institute of Applied Physics and Computational Mathematics, Beijing 100094, China
3 Center for Plasma Physics, School of Mathematics and Physics, Queenaŕs
˛ University
Belfast, Belfast BT7 1NN, United Kingdom
Laser-driven ion acceleration has the potential to be compact sources of energetic ions, which
can be applied for proton radiography, tumor therapy, inertial fusion energy and warm dense
matter [1]. Several acceleration mechanisms have been proposed, in which radiation pressure
acceleration (RPA) promises higher scaling and laser-ion conversion efficiency and monoener-
1 nc
getic ion beams with the optimal condition lo = π ne a0 λ , with lo , nc , ne , a0 and λ the target
thickness, the critical density, the electron density, the normalized laser amplitude and the laser
wavelength [2]. However, experiments and simulations show that the pulse can punch through
the target during the acceleration even under the optimal condition as various instabilities set
in and grow nonlinearly with time and other parameters during the laser plasma interactions,
which will terminate the acceleration early and reduce the conversion efficiency and beam qual-
ity [1, 3]. Through theoretical and simulation studies, we show that the optimal condition of
RPA is related to the pulse duration, the ellipticity of the elliptically polarized laser pulse and
the scale length of the preplasma. With the modified optimal condition, the acceleration can
maintain stable until the pulse ends and the quality of ion beams is improved. Meanwhile, the
conversion efficiency can be increased two times.
References
[1] A. Macchi, M. Borghesi, and M. Passoni, Rev. Mod. Phys. 85, 751 (2013).
[2] B. Qiao, M. Zepf, M. Borghesi, and M. Geissler, Phys. Rev. Lett. 102, 145002 (2009).
[3] X. F. Shen, B. Qiao, H. Zhang, S. Kar, C. T. Zhou, H. X. Chang, M. Borghesi and X. T. He, Phys. Rev. Lett.
118, 204802 (2017).
