Effect of laser intensity on fast-electron-beam divergence in solid-density plasmas
Effect of laser intensity on fast-electron-beam divergence in solid-density plasmas
复制标题
DOI：
10.1103/physrevlett.100.015003
复制
发表时间：
2008-01-11
影响因子：
8.6
通讯作者：
Norreys, P. A.
中科院分区：
文献类型：
--
作者：
Green, J. S.;Ovchinnikov, V. M.;Norreys, P. A.
用波长为1微米、持续时间为5ps、聚焦强度(I)高达4×10(19)W cm(-2)的激光脉冲照射金属箔靶，得到的Ilambda(2)和脉冲持续时间与快速点火惯性聚变所需的值相当。通过X射线K-α发射的空间分辨测量和对箔背面形成的等离子体的横向探测，确定了加速进入靶的电子的发散度。与其他已发表数据的比较表明，它随Ilambda(2)增大而增大，与脉冲宽度无关。二维粒子模拟再现了这些结果，表明这是激光-等离子体相互作用的一个基本性质。
Metal foil targets were irradiated with 1 mu m wavelength (lambda) laser pulses of 5 ps duration and focused intensities (I) of up to 4x10(19) W cm(-2), giving values of both I lambda(2) and pulse duration comparable to those required for fast ignition inertial fusion. The divergence of the electrons accelerated into the target was determined from spatially resolved measurements of x-ray K-alpha emission and from transverse probing of the plasma formed on the back of the foils. Comparison of the divergence with other published data shows that it increases with I lambda(2) and is independent of pulse duration. Two-dimensional particle-in-cell simulations reproduce these results, indicating that it is a fundamental property of the laser-plasma interaction.