基于激光尾波场加速的超快辐射源及瞬态X射线成像研究

The laser-wakefield driven by an ultra-intense ultra-short laser pulse can maintain a ultrahigh accelerating gradient on the order of 100GV/m，which is increased three orders of magnitude compared with the conventional accelerator. It can produce GeV-class electron beams over a distance of centimeter-scale and thus greatly reduce the size and cost of the accelerators. Meanwhile, with these laser-wakefield accelerated electron beams, high energy X-ray sources can be generated and qualify themselves with the characteristics of table-top, tunability, high brightness, small source size, ultrashort duration and high collimation. They thus hold a wide range of potential application and requirement in many fields, such as high-spatial resolution transient imaging, phase-contrast microtomography and non-destructive inspection and so on. These novel X-ray sources will also provide new means and techniques for priority cross-basic studies and other fields, having greatly important scientific significance. Based on the related research background and foundation, this project will focus on the generation of high-quality and bright Betatron radiation and all-optical self-synchronized Compton scattering sources with the laser-wakefield accelerated electron beam. By improving the stability, tunability and application properties of the radiation sources, we will perform high-resolution transient high-energy X-ray imaging of the prepared samples made with different materials and thickness. Some effective and suitable transient imaging techniques for the measurements and diagnostic will be developed accordingly. Deep studies will then be explored firstly on the material dynamic crack growth，solid macro-micro deformation and non-destructive detection and to lay the foundation for further researches.

超强超短激光驱动的激光尾波场加速梯度可达100GV/m，比传统电子加速器提高了三个量级，可在厘米加速长度内获得GeV量级的电子束源，极大地降低加速器的规模和成本。与此同时，利用激光尾波场加速的电子束可进一步产生台式化、可调谐、高亮度、源尺寸小、超短脉宽、准直的高能X射线源，在高空间分辨瞬态成像、相衬层析成像及无损检测等方面具有广泛的应用前景和需求，可为前沿交叉学科及众多的领域提供新手段和新技术，具有重要的科学研究意义。基于相关的研究背景和基础，本项目拟围绕激光尾波场加速电子并驱动产生高性能、高亮度的Betatron辐射源和全光自同步逆康普顿散射源；通过提高辐射源的稳定性、调谐性及其应用性能，从而对不同材料、不同厚度的预制样品进行瞬态高能X射线成像研究；建立和发展有效、适用的瞬态成像测量方法和诊断技术，并为后续进一步开展材料动态裂纹扩展、固体宏微观形变及无损探伤等研究奠定基础和提供依据。

超强短脉冲激光驱动的激光尾波场加速梯度可达100GV/m，可在厘米加速长度内获得GeV量级的高性能高亮度电子束源，还可进一步产生台式化、可调谐、高亮度、源尺寸小、超短脉宽、准直的高能X射线源，可为高时空分辨瞬态成像、相衬层析成像及无损检测等前沿交叉学科及应用研究提供新手段和新技术。. 本项目围绕激光尾波场加速产生稳定、高性能的超快电子束源及其所驱动的高能量、高亮度的新型辐射源，如Betatron辐射源、全光逆康普顿散射源和自由电子激光；通过提高电子束源和辐射源的稳定性、调谐性及其应用性能，对不同材料、不同厚度的预制样品进行了瞬态高能X射线成像实验研究；初步建立和发展了有效、适用的瞬态成像测量方法和诊断技术；基于新建立的实验平台，通过对重频高功率飞秒激光参数的优化和提升，开展了基于激光电子加速新方案产生的超快电子束源及高强度新波段辐射源的实验和模拟研究；并进一步探索了材料动态演化、无损探测和超快瞬态成像的新技术和新方案。