fundamental research on amplified spontaneous emission of γ-ray with an intense femtosecond laser

为探讨强短脉冲激光等离子体辐射（电子、离子和x射线）激发核产生g射线的可行性，建立了数据库，并进行了初步实验。特别是编制了电子跃迁核激发可行的元素及其跃迁，并证明了簇气的库仑爆炸是产生高能离子的一种方式。#研究了核数据表中所有可行的元素和跃迁，并提交给原子数据和核数据表（待发表）#完成了激光-星团气体相互作用（氢，氩）实验，观察到高能离子的产生。#对于库仑爆炸产生的离子，研究了离子能量对激光强度的依赖关系，能量表明离子是由电子撞击电离部分电离的，并且有可能由激光场加速的电子使内层电子电离。#如果将来有更高强度的激光，在强光场电离过程中，内壳层电子可以被电离，依次产生NEET，当等离子体体积足够大时，在NEET作用下，等离子体中的γ射线可以被放大。

To investigate the future feasibility of the generation of g-ray from nucleus excited by radiations(electrons, ions, and x-ray) emitted from the plasmas produced with an intense short pulse laser, the data-base has been compiled and preliminary experiment has been done. Especially, the elements and their transitions feasible for NEET (nuclear excitation by electron transition has been compiled and as one way to generate energetic ions Coulomb-Explosion of cluster gas was demonstrated.# Investigated all nucleus data from Nuclear Data Sheets for the elements and transitions feasible for r NEET, and submitted to the Atomic Data and Nuclear Data Tables (to be published)# Laser-cluster gas interaction (hydrogen, argon) experiment has been done, and energetic ion generation was observed.# For the ions generated by Coulomb explosion, ion energy dependence on laser intensity was studied, and the energy suggested that the ions are partially ionized by electron impact ionization, and it may be possible to ionized inner shell electrons by electron accelerated by laser field.# If in future higher intensity laser will be available, in the process of ionization in intense optical field inner shell electrons can be ionized inducing sequentially NEET, and with the plasma volume large enough for stimulate emission, γ-ray can be amplified in the plasma under NEET.