超短超强激光与Cu靶相互作用中质子背向发射的实验测量

 在20TW激光器上进行了超短超强激光与金属Cu膜靶的相互作用实验，当靶厚度不同时，采用CR39核径迹探测器测量了质子发射的空间分布和产额；使用Thomson磁谱仪测量了靶背法线方向质子束的能量分布。测量结果表明：质子产额为10⁵～10⁶每发；质子束沿靶背法线方向发射，与入射激光方向无关，并且存在较小的发射立体角，在一定能量处出现截止，截止能量的大小与靶厚度有关。

Measurement of proton jet in the interaction of ultra-short ultra-intense laser with Cu foil target

This paper reports the experimental research on the interaction of ultra-short and ultra-intense laser with Cu foil target. The spatial distributions and yield of the protons with different target thicknesses were recorded by nuclear track detector CR39. And the proton energy spectrum was measured by Thomson magnetic spectrometer. The results show that about 10~ 5～10~ 6 high energy protons jet only in the direction normal to the surface of target within a little cone angle. A sharp cutoff energy exists in the proton energy spectrum, and it depends on the target thickness.