Cross-focusing of two chirped Gaussian laser beams and THz wave generation in plasmas of multi-ion species under a weakly relativistic and ponderomotive regime

作     者：M R JAFARI MILANI S REZAEI M J JAFARI M R JAFARI MILANI;S REZAEI;M J JAFARI

作者机构：Photonics and Quantum Technologies Research SchoolNuclear Science and Technology Research InstituteTehran 14665-678Iran Plasma and Fusion Research SchoolNuclear Science and Technology Research InstituteTehran 14399-51113Iran 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2022年第24卷第10期

页      面：1-11页

核心收录：

学科分类：07[理学] 070204[理学-等离子体物理] 0702[理学-物理学] 

主　　题：laser–plasma interaction THz generation chirped Gaussian laser beams 

摘      要：The generation of terahertz(THz)waves via the beating of two high-intensity chirped Gaussian lasers in a multi-ion-species plasma is numerically studied by taking into account the weak relativistic and ponderomotive regime of *** coupled differential equations for beamwidth parameters are extracted by introducing the dielectric function of such plasma and using WKB and paraxial ray *** amplitude of THz radiation at beat frequency resulting from the nonlinear current density induced by the beat ponderomotive force of the cross-focusing of beams was *** impacts of the chirp frequency parameter,initial laser intensity and initial ionic species density(specifically,the presence of singly and doubly charged ions)in the plasma on THz generation were *** numerical results reveal that THz radiation generation strongly depends on the chirp frequency parameter.A specific range of chirp frequencies exists for self-focusing as well as THz generation with a turning point ,where the THz emission reaches its maximum *** results show that the strength of self-focusing and consequently the generated THz radiation are reduced by increasing the density of doubly charged ionic species in the plasma due to the suppression of the nonlinear effects.