[Study on the emission spectra of aluminum plasma induced by high energy laser]

The intensities of emission spectra of laser-induced alloy aluminum plasma, with the use of a neodymium glass laser (laser pulse energy is about 25 J), were experimentally studied in argon atmosphere. The effects of atmosphere pressure, height from the observed location of the plasma to the sample surface, operating voltage, and power density of the laser on the signal intensities of emission spectra were discussed. Experimental results showed that the intensities of emission spectra are strongest under 88 kPa of gas pressure. With the increase of the height from the observed location of the plasma to the sample surface, the intensities of emission spectra decrease clearly. At the pressure of 88 kPa and the height of 1.5-2 mm, the emission spectra have maximum intensities. In addition, the spectral line intensities are enhanced significantly with the increase of operating voltage and power density.