Plasma Spectral Characteristics Of Hexagonal Boron Nitride Ceramics Irradiated By Pulsed Laser

Plasma will be produced on the surface of hexagonal boron nitride material irradiated by pulsed laser.the damage threshold,composition elements and plasma parameter characteristics of the target are studied and analyzed by plasma emission spectrum.In this paper,hexagonal boron nitride is selected as the target material.firstly,the XRD phase analysis of the material is carried out to ensure the singularity of the material,and then an experimental platform is set up to irradiate hexagonal boron nitride by nanosecond pulse laser.The damage threshold of the material was studied by plasma spectroscopy,and the damage morphology of the material was used to prove the accuracy of the plasma spectrum in measuring the damage threshold.Finally,the zero probability damage method is used to fit the test results,and the measured damage threshold is 0.182J·cm^-2.In air environment,hexagonal boron nitride target is irradiated by nanosecond pulse laser of Nd:YAG laser,and the obtained hexagonal boron nitride plasma spectrum is identified and analyzed.The characteristic peaks of boron in the target are B I 208.17nm,B I249.69nm and B II 345.6nm.Under the condition that the plasma is in local thermal equilibrium,Boltzmann double line method and Stark broadening method are selected to solve the electron temperature and electron density of the plasma,respectively.And in the range of 0.64J·cm^-2 to 5.1J·cm^-2 of laser energy density,The variation of plasma electron temperature and electron density is studied and analyzed.