不知道是不是火星了

虽然早听说APS有这种服务，不过今天还真是第一次注意到
具体是啥大家一看就明白了，PRL的文章

Generating High-Current Monoenergetic Proton Beams by a CircularlyPolarized Laser Pulse in the Phase-StableAcceleration Regime

X. Q. Yan (颜学庆),^1,5 C. Lin (林晨),¹ Z. M. Sheng (盛政明),^1,2,3 Z. Y. Guo (郭之虞),¹ B. C. Liu (刘必成),^1,4 Y. R. Lu (陆元荣),¹ J. X. Fang (方家驯),¹ and J. E. Chen (陈佳洱)¹

¹State Key Laboratory of Nuclear Physics and Technology, Instituteof Heavy Ion Physics, Peking University, Beijing100871, China

²Beijing National Laboratory for Condensed Matter Physics,Institute of Physics, CAS, Beijing 100080, China

³Department of Physics, Shanghai Jiao Tong University,Shanghai 200240, China

⁴The Graduate University of Chinese Academy ofScience, Beijing, China

⁵Center for Applied Physics and Technology, PekingUniversity, Beijing 100871, China

(Received 24 October 2007; published 3 April 2008)

A new ion acceleration method, namely, phase-stable acceleration, usingcircularly-polarized laser pulses is proposed. When the initial target density n₀ and thickness D satisfy a_L~(n₀/n_c)D/_L and D>l_s with a_L, _L, l_s, and n_c the normalized laser amplitude, the laser wavelength invacuum, the plasma skin depth, and the critical density of the incident laserpulse, respectively, a quasiequilibrium for the electrons is established bythe light pressure and the space charge electrostatic field at the interactingfront of the laser pulse. The ions within the skin depth of the laser pulseare synchronously accelerated and bunched by the electrostatic field, andthereby a high-intensity monoenergetic proton beam can be generated. The protondynamics is investigated analytically and the results are verified by one-and two-dimensional particle-in-cell simulations.