激光等离子体加速器:原理、现状以及展望

<正>上帝粒子"希格斯"的发现成就了2013年诺贝尔物理学奖的归属,高能粒子加速器LHC(图1)又一次成为了人们视线的焦点。粒子加速器不仅是高能粒子物理和核物理等高端物理研究的基础工具,利用加速器产生的多波段辐射也在材料、化学、生物和医疗等领域有着广泛的应用。传统粒子加速器受到材料电离击穿阈值的限制,其加速梯度被限制在100 MV/m。如费米所言,     

Generating Proton Beams Exceeding 10 MeV Using High Contrast 60TW Laser

A prototype of a laser driven proton accelerator is built at Peking University. Protons exceeding 10 MeV are accelerated from micrometer-thick aluminum targets irradiated by tightly focused laser pulse with 1.8 J energy and 30 fs duration. The beam energy spectrum and charge distribution are measured by a Thomson parabola spectrometer and radiochromic film stacks. The sensitivity of proton cut-off energy to the focusing of the laser beam, the pulse duration, and the foil thickness are systematically investigated in the experiments. Stable proton beams have been produced with an optimized parameter set, providing a cornerstone for the future applications of laser accelerated protons.