Laser induced breakdown spectroscopy of zinc, cadmium and mercury plasma parameters produced by the 1064 nm, 532 nm, and 355 nm OF Nd:YAG laser

Summary form only given. We report the measurements of the zinc, cadmium and mercury plasma parameters produced by the fundamental mode of a Nd:YAG laser. From the spectroscopic analysis of the observed spectral lines we have estimated the excitation temperature and the electron number density using the Boltzmann plots and the Stark broadened profiles of the spectral lines respectively. The temporal evolution of the plasma has also been investigated at the atmospheric ambient pressure and found that both the integrated intensity and width of the spectral lines decreases with the time delay. The estimated values of plasma parameters in the temporal behavior has been estimated as, in the case of zinc plasma these parameters varies as [T ~ (11018 - 5635 ) K, Ne ~ (1.2x10¹⁷ - 3.15x10¹⁶) cm^-3], whereas in the case of cadmium plasma [T ~ (11294 -6372) K, Ne ~ (1.03x10¹⁷ - 1.93x10¹⁶) cm^-3] at the delay time of (0.1 - 7.5) ?s , similarly mercury plasma parameters varies as [T ~ (14050 -6369) K, Ne ~ (4x10¹⁷ - 7.3x10¹⁶) cm^-3] at the delay time of (0.1 - 5.5) ?s. The recombination rate constant of the plasma has been estimated using the relation2 dN_{_e}/dt=k_ion N_eN_i-K_recN_e ³ (1) dt Where N_e (cm^-3) and N_i (cm^-3) are the electrons and heavy particle densities, respectively, whereas kion (cm³ s^-1) and K_rec (cm⁶s^-1) are the ionization and recombination rate coefficients. It is found that the recombination rate of the mercury plasma is much higher than the zinc and cadmium plasma. Besides that we have estimate the stark broadening parameters of the zinc and cadmium transition lines at the reduced argon ambient pressure and found to be in good agreement with the available data in the literature. We have also stud- ed the behavior of the emission lines in the plasma at different pressures. It is noticed that the intensities of all the observed spectral lines of Zn (I), Zn (II), Cd (I), Cd (II) and Hg (I), Hg (II) decreases with the decrease of the air pressure.