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

为了研究利用短脉冲强激光产生的等离子体辐射（电子、离子和x射线）激发原子核产生g射线的可行性，编制了数据库，并进行了初步实验。特别是，NEET（通过电子跃迁的核激发）可行的元素和它们的跃迁已经被编译并且作为一种产生高能离子的方式被证明了团簇气体的库仑爆炸。研究了原子核数据表中的所有原子核数据，为r NEET提供了可行的元素和跃迁，并提交给原子数据和核数据表（即将出版）#激光团簇气体相互作用（氢，氩）实验已经完成，并观察到高能离子产生。对于库仑爆炸产生的离子，研究了离子能量与激光强度的关系，结果表明，电子碰撞电离使离子部分电离，激光场加速电子电离内层电子是可能的。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，从而诱发NEET，而当等离子体体积足够大时，在NEET下，γ射线可以在等离子体中被放大。

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.