强激光与等离子体作用中的孤子与粒子加速的研究

项目名称： 强激光与等离子体作用中的孤子与粒子加速的研究

项目编号： No.10875015

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 无线电电子学、电信技术

项目作者： 谢柏松

作者单位： 北京师范大学

项目金额： 30万元

中文摘要： 本项目完成了在等离子体尾场下的电子加速，激光等离子体相互作用下的空泡电子加速及优化，非均匀磁场下的真空电子加速，激光与等离子体薄膜靶相互作用下的离子加速，以及有预等离子体通道时激光传播存在类孤子型解等几个方面的预期研究任务，取得了丰硕成果,有17篇SCI论文在包括Appl Phys Lett和Phys Plasmas等杂志在内的国内外核心期刊上发表。本项目取得的主要成果有：（1）对强激光脉冲和非均匀外加磁场下的电子共振加速问题，通过合适地提供有横向梯度变化的轴向磁场，其非线性的激光驱动电子共振加速机制可使电子加速到GeV水平。(2)提出用内径在空泡初始和最大横向半径之间的高密度等离子体管壁来优化电子加速的方案，该方案可抑制电子进一步注入, 从而提高了加速梯度并能够实现准稳相加速。（3）通过考虑辐射压的相对论性修正后的优化靶厚而实现离子的稳定加速。（4）离子的荷质比对辐射压力加速机制中离子加速稳定性影响较大,通过氚离子和被加速离子在加速过程中形成的分层结构, 可以使氚离子层有效地缓冲各种不稳定性从而实现某些低荷质比离子相对稳定的加速。（5）有预等离子体通道时激光传播存在类孤子型解。

中文关键词： 超强超短激光；尾场加速；空泡加速；辐射压加速；孤子

英文摘要： Project has been completed by studing some topics on electrons wakefield and bubble accelerations, vacuum acceleration in magnetic field and ions acceleration by laser-foil interaction as well soliton wave propagation of laser in plasma channel. Research results have been reported in 17 SCI papers which appeared in many important journals including Appl Phys Lett and Phys Plasma. Main results and conclusions are: (1) A magnetic resonance electrons acceleration mechanism has been confirmed by an appropriate axial magnetic field with transverse variation that make the electrons net energy gain to reach GeV. (2) A dense plasma wall sized about the bubble transverse one has been proposed to optimize the bubble acceleration scheme, which not only suppress the electrons continuous self- injection but also enhance the acceleration field gradient, so that the stable phase acceleration can be realized. (3) By considering relativistic modification of radiation pressure on the optimized target thickness one can obtain more stable ions acceleration. (4) It is found that charge-to-mass (cm) ratio of ions plays an important role on stability of ions acceleration in radiation pressure acceleration mechanism. Due to a separation structure between tritium ions and other ions in accelerated stage one can expect that the tritium ions layer would suppress the instability and enable a stable acceleration of lower cm ions. (4) Some soliton waves of laser pulse have been obtained in preformed plasma channnel by considering various effects such as nonlinear ponderomotive and wakefield coupling.

英文关键词： ultraintense ultrashort laser; wakefield acceleration; bubble acceleration; radiative pressure acceleration; soliton