Optical spectroscopy of plasma produced by laser ablation of Ti alloy in air

Time‐resolved emission spectrum from the plasma produced by 1.06 μm, 10 ns pulsed‐laser irradiation of titanium alloy targets in air at a flux of 9.3×109 W cm−2 was analyzed in the wavelength range of 2000–8800 A. From the evolutions of the specific spectrum lines of N II, Ti I, and Fe I, the velocities of N+ ions and the excited neutral Ti and Fe atoms have been obtained using a time‐of‐flight diagnostic method. The electron temperatures were deduced using the relative emission intensities of N II and Fe I isolated spectrum lines, and an electron number density was determined from the Stark‐broadened line of the N II line at wavelength λ=3995 A.