LAUSR

An enhancing proton acceleration scheme is proposed by applying an external axial magnetic field in the leaky light-sail regime when a right-hand circularly polarized laser interacts with a multispecies nanofoil. In this scheme, the external axial magnetic field B0 can not only enhance the intensity of the accelerating electric field but also adjust the spatial distribution of the accelerating electric field. It is shown by 2D3V particle-in-cell simulations that a monoenergetic proton beam could be produced in the case of B 0 = 2. Compared with the case of B 0 = 0, the peak energy increases by 50% and the number improves by a factor of two when the laser intensity is 3.4 × 10 19 W / cm 2. Besides, the angle divergence of protons can be greatly improved by manipulating the shape of accelerating electric field from concave to convex under the influence of the B 0 = 2. These results may be helpful to understand the process of particle motion in a strongly magnetized plasma.