飞秒激光中高能质子的产生与加速的研究

为了探索飞秒激光与固体靶相互作用中高能质子的产生和加速机制，在超短超强激光装置“SILEX-I”上进行了飞秒激光与平面固体薄膜Cu靶的相互作用中高能质子空间分布、能谱和产额的实验研究。实验采用固体核径迹探测器CR39和Thomson离子谱仪相结合的方式，在固体靶背表面法线方向测量了质子空间分布、能谱和产额。实验结果表明：质子沿着靶背法线方向发射，质子空间分布呈圆环状，存在一定的立体角；质子在一定能量处出现截断；截断能量的大小与靶厚度有关。经分析，高能离子的产生和加速是多种作用机制共同作用的结果，其中静电场中的TNSA加速机制则占主导地位。

Study of High Energy Protons Generate and Accelerate in Femtosecond Laser Interaction

To study the generation and the acceleration mechanisms of high energy protons in the interaction of femtosecond laser with solid targets, high energy protons behavior at the normal direction of the rear surface of the target produced from ulintencity pulse laser irradiated Cu thin film solid targets was explored on SILEX-I laser facility. The solid nuclear detector CR39 and Thomson spectrum are use to detect the spatial distribution and energy spectrum and yields of protons. The result is shown that: the protons are emitted from the normal direction of target-back, proton assumes the circular annular space distribution, there is a solid Angle; the protons have a certain cut-off energy; cut-off energy size and thickness of the target. The analysis, High-energy proton generation and acceleration is a variety of mechanisms of the result of joint action, among them, the electrostatic field TNSA acceleration mechanism is dominant.