Kinetic Study Of Longitudinal Plasma Wave Modes Carrying Orbital Angular Momentum

Laguerre-Gaussian(LG)laser beams carrying orbital angular momentum(OAM)have been extensively studied in the optical field.The invention of optical tweezers based on OAM laser beams has become one of the most important tools for fine manipulation in medicine and biology;OAM multiplexing technology is also expected to achieve a breakthrough for information transmission methods in wireless communication.Therefore,the research related to OAM and its applications have aroused the interest of many scholars.In recent years,there has been a boom in the research of OAM coupling with plasma waves in plasma,and plasma waves may also carrying OAM.Studies have shown that plasma waves carrying OAM have a helical structure different from that of plane waves.Due to their spectrum modulation,power-concentrated structure and rotational characteristics,OAM wave modes have significant potential applications in plasma diagnostics,heating,current driving in magnetic confinement fusion devices,and stable driving of rotating charged particle beams in high-intensity acceleration.In this thesis,the propagation properties of ion-acoustic waves carrying finite OAM in Maxwellian plasma system are revisited within the plasma kinetic theory regimes by adopting a new variable transformation.It is shown that dispersion and damping of ion-acoustic waves are modified by OAM,and the conclusion formulae derived from the introduction of the variational transform can describe the propagation and damping of the ion acoustic wave in a more natural way.Furthermore,the propagation characteristics of electrostatic waves carrying finite OAM were investigated in non-extensive and κ-deformed Kaniadakis distributed plasma system,respectively.The results show that the peculiarities of the investigated subjects rely on the non-extensive parameter q,deformation parameter κ and OAM parameter η.For ion acoustic wave in non-extensive distributed plasma system,as q increases,the range of normalized wave number expands,with dispersion weakening and damping increasing.In contrast,as η increases,dispersion enhances and damping weakens.For both Langmuir and ion-acoustic waves in κ-deformed Kaniadakis distributed plasma system,dispersion was enhanced with increased κ,while the Landau damping was suppressed.Conversely,both the dispersion and Landau damping were depressed by OAM.It was expected that the present results would give more insight into the trapping and transportation of plasma particles and energy.Moreover,the results may provide a reference for the studies of nonlinear OAM wave modes in plasma.