Electron beam and betatron x-ray generation in a hybrid electron accelerator driven by high intensity picosecond laser pulses
Electron beam and betatron x-ray generation in a hybrid electron accelerator driven by high intensity picosecond laser pulses
复制标题
由高强度皮秒激光脉冲驱动的混合电子加速器中的电子束和电子感应加速器 X 射线生成
DOI：
10.1016/j.hedp.2020.100859
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发表时间：
2020-11-01
影响因子：
1.6
通讯作者：
Chen, L. M.
中科院分区：
文献类型：
--
作者：
Li, Y. F.;Feng, J.;Chen, L. M.
我们实验研究了1-3×10(19)W/cm(2)高强度皮秒激光脉冲与1-8×10(19)cm(-3)低密度等离子体相互作用产生的电子束和同步辐射。实验中产生了最大能量超过120 MeV的电子束、数百mrad发散和数十个NC电荷。测量的X射线能谱与同步辐射能谱和韧致辐射能谱符合得很好。当激光脉冲强度为2.38×10(19)W/cm(2)与密度为2.35×10(18)cm(-3)的纯氮气相互作用时，获得了临界能量为3-4keV、光子数为10(13)光子/sr的高能X射线辐射，能量转换效率约为3×10(-5)。高的光子产额和高的能量转换效率是由于大量的电子被自调制激光尾场俘获，并且主要是由直接激光加速机制加速的。这种高产额的高能电子X射线源在用于高能量密度或聚变科学的大型激光装置中作为背光或探测器具有广泛的应用前景。
We experimentally studied electron beams and synchrotron x-ray radiation generated from the interaction of high-intensity picosecond laser pulses of 1-3 x 10(19) W/cm(2) with underdense plasmas of 1-8 x 10(19) cm(-3). Electron beams with maximum energy over 120 MeV, hundreds mrad divergence and tens of nC charge were generated in the experiments. The measured x-ray spectra were fit well with a synchrotron radiation spectrum combination with a bremsstrahlung spectrum. When laser pulses with intensity of 2.38 x 10(19) W/cm(2) interacting with pure Nitrogen gas with density of 2.35 x 10(18) cm(-3), we obtained betatron x-ray radiation with critical energy 3-4 keV and photon number up to 10(13) photons/Sr per shot, the energy conversion efficiency is about 3 x 10(-5). The high photon yield and large energy conversion efficiency are due to large amounts of electrons trapped by self-modulated laser wakefield and mainly accelerated by direct-laser-acceleration mechanism. Such high yield betatron x-ray sources have widely application prospect as backlight or probe in large scale of laser facilities used for high energy density or fusion sciences.