Two-dimensional investigation of characteristic parameters and their gradients for the self-generated electric and magnetic fields of laser-induced zirconium plasma  

作　　者：Tayyaba SAJID Shazia BASHIR Mahreen AKRAM Maira RAZZAQ Khaliq MAHMOOD Tayyaba SAJID;Shazia BASHIR;Mahreen AKRAM;Maira RAZZAQ;Khaliq MAHMOOD(Centre for Advanced Studies in Physics,Institute of Physics,Government College University Lahore,Lahore 54000,Pakistan;Department of Physics,Institute of Physics,Government College University Lahore,Lahore 54000,Pakistan)

机构地区：[1]Centre for Advanced Studies in Physics,Institute of Physics,Government College University Lahore,Lahore 54000,Pakistan [2]Department of Physics,Institute of Physics,Government College University Lahore,Lahore 54000,Pakistan

出　　处：《Plasma Science and Technology》2024年第5期138-155,共18页等离子体科学和技术（英文版）

摘　　要：Two-dimensional diagnosis of laser-induced zirconium(Zr)plasma has been experimentally performed using the time-of-flight method by employing Faraday cups in addition to electric and magnetic probes.The characteristic parameters of laser-induced Zr plasma have been evaluated as a function of different laser irradiances ranging from 4.5 to 11.7 GW cm-2 at different axial positions of 1–4 cm with a fixed radial distance of 2 cm.A well-supporting correlation between the plume parameters and the laser-plasma-produced spontaneous electric and magnetic(E and B)fields was established.The measurements of the characteristic parameters and spontaneously induced fields were observed to have an increasing trend with the increasing laser irradiance.However,when increasing the spatial distance in both the axial and radial directions,the plasma parameters(electron/ion number density,temperature and kinetic energy)did not show either continuously increasing or decreasing trends due to various kinetic and dynamic processes during the spatial evolution of the plume.However,the E and B fields were observed to be always diffusing away from the target.The radial component of electron number densities remained higher than the axial number density component,whereas the axial ion number density at all laser irradiances and axial distances remained higher than the radial ion number density.The higher axial self-generated electric field(SGEF)values than radial SGEF values are correlated with the effective charge-separation mechanism of electrons and ions.The generation of a self-generated magnetic field is observed dominantly in the radial direction at increasing laser irradiance as compared to the axial one due to the deflection of fast-moving electrons and the persistence of two-electron temperature on the radial axis.

关 键 词：Faraday cup axial and radial expansion space-charge effect laser-induced zirconium plasma two-electron temperature distribution self-generated electric and magnetic fields 

分 类 号：O53[理学—等离子体物理]