Investigation into the Effect of Increasing Target Temperature and the Size of Cavity Confinements on Laser-Induced Plasmas

Abstract

In this work, the effect of the sample temperature on the magnesium (Mg) and titanium (Ti) plasmas generated by a Q-switched Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser operating at its fundamental wavelength of 1064 nm has been investigated. We observed that increasing the sample temperature significantly enhanced the emission intensities of the plasmas. Comparing the emission peak intensities of the case of 100 °C to the case of 300 °C, we recorded a substantial enhancement of the peak intensities of the latter compared to the former. From these results it can be observed that increasing the sample temperature has a significant effect on the emission intensities of the plasmas. We also studied the plasma dynamics and found that increasing the sample temperature also decreases the air density around the Mg sample surface. The reduction in the air density resulted in a decrease in the radiation process and lowers collision probability. Furthermore, as the plasma expands, the plasma pressure also decreases. In addition, we also employed circular and square cavities to confine the titanium plasma, and investigated the effect of the sizes of the circular and square cavities on the titanium plasma. We observed a general improvement in the emission intensities with both the circular and square cavities and attributed this improvement to the plasma compression effect of the shock waves produced by the plasma within the cavities.