Self-focusing, channel formation, and high-energy ion generation in interaction of an intense short laser pulse with a He jet.
Self-focusing, channel formation, and high-energy ion generation in interaction of an intense short laser pulse with a He jet.
复制标题
DOI：
10.1103/physreve.59.7042
复制
发表时间：
1999-06
期刊：
影响因子：
--
通讯作者：
G. Sarkisov;B. Y. Bychenkov;V. Novikov;V. Tikhonchuk;A. Maksimchuk;Shouyuan Chen;R. Wagner;
中科院分区：
文献类型：
--
作者：
G. Sarkisov;B. Y. Bychenkov;V. Novikov;V. Tikhonchuk;A. Maksimchuk;Shouyuan Chen;R. Wagner;
利用干涉法研究了相对论强度为4 TW，400 fs的激光脉冲与He气体射流相互作用的动力学。我们观察到一个稳定的等离子体通道，长1 mm，直径小于30 microm，径向电子密度梯度约为5 x 10（22）cm（-4），轴上电子密度约为最大值8 x 10（19）cm（-3）的10倍。通道形成后，观察到周围气体电离的高径向速度约为3.8 × 10（8）cm/s，这归因于从激光通道排出并径向向外传播的快离子。我们开发了一个动力学模型，它描述了等离子体通道的形成和随后的环境气体的激发和电离。将模型预测结果与干涉测量数据进行比较，重建了激光通道的轴向轮廓和轴上激光强度。加速离子的最大能量约为500 keV，快离子的总能量约为激光脉冲能量的5%。
Using interferometry, we investigate the dynamics of interaction of a relativistically intense 4-TW, 400-fs laser pulse with a He gas jet. We observe a stable plasma channel 1 mm long and less than 30 microm in diameter, with a radial gradient of electron density approximately 5 x 10(22) cm(-4) and with an on-axis electron density approximately ten times less than its maximum value of 8 x 10(19) cm(-3). A high radial velocity of the surrounding gas ionization of approximately 3.8 x 10(8) cm/s has been observed after the channel formation, and it is attributed to the fast ions expelled from the laser channel and propagating radially outward. We developed a kinetic model which describes the plasma channel formation and the subsequent ambient gas excitation and ionization. Comparing the model predictions with the interferometric data, we reconstructed the axial profile of laser channel and on-axis laser intensity. The estimated maximum energy of accelerated ions is about 500 keV, and the total energy of the fast ions is 5% of the laser pulse energy.