飞秒激光-等离子体相互作用中快电子能量分布

 采用不同量程的电子谱仪与LiF热释光探测器相配合，测量了飞秒激光 等离子体相互作用中产生的快电子能量分布。结果显示快电子能量分布的一致性和多个重要特征与国外同类实验和计算机模拟结果相似。快电子能谱在低能处产生凹陷是由于冷电子的回流产生的；几种加速机制共同作用是能谱在100~350 keV范围内出现平台的原因；快电子的有效温度较好地满足共振吸收的温度定标律是由于反射激光加速与共振吸收机制均是通过朗道阻尼或波破对电子进行加速的。

Fast electron energy distribution in femtosecond laser plasma interactions

The energy distributions of fast electrons in fs laser-plasma interactions have been measured using the magnetic spectrometers with various magnetic fields,fitted with the LiF thermoluminescent dosimeters(TLDs).The results show that the consistency and the important characters of energy distribution of fast electrons,which are similar to those of the experiment and simulation made by others.There is a concavity at 40 keV,which is due to the return current of cold electrons;and a local plateau of electrons with energies 100~350 keV,which is produced by several acceleration mechanisms in energy distribution.The effective temperature of fast electrons is consistent with the temperature scaling of the resonance absorption,which is due to Landau damping or wave breaking.