Numerical Investigation of the Tri-Atomic Ions Formation during Laser Ionization Based on Resonance Saturation

作     者：M. A. Abdelati M. A. Mahmoud Y. E. E. Gamal 

作者机构：National Institute of Laser Enhanced Sciences Cairo University El Giza Egypt Physics Department Faculty of Science Sohag University Sohag Egypt 

出 版 物：《Journal of Applied Mathematics and Physics》 (应用数学与应用物理（英文）)

年 卷 期：2014年第2卷第12期

页      面：1123-1129页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Plasma Laser Collisional Ionization Association Ionization Tri-Atomic Ions Photoionization Electron Energy Distribution Function 

摘      要：We present a theoretical investigation of plasma generation in sodium vapor induced by laser radiation tuned to the first resonance line (3S-3P) at λ = 589 ns. A set of rate equations that describe the rate of change of the ground and excited states population as well as the temporal variation of the electron energy distribution function (EEDF), beside the formed atomic ion Na+, molecular ion ?and tri-atomic ions are solved numerically. The calculations are carried out at different laser energy and different sodium atomic vapor densities under the experimental conditions of Tapalian and Smith (1993) to test the existence of the formed tri-atomic ions. The numerical calculations of the electron energy distribution function (EEDF) show that a deviation from the Maxwellian distribution due to the super elastic collisions effect. In addition to the competition between associative ionization (3P-3P), associative ionization (3P-3D) and Molnar-Horn- beck ionization processes for producing , the calculations have also shown that the atomic ions Na+ are formed through the Penning ionization and photoionization processes. These results are found to be consistent with the experimental observations.