Optical properties of laser-produced plasmas from Cd and layered crystalline CdAl2Se4 targets

An experimental investigation into emission by plasmas from Cd and crystalline CdAl2Se4 targets irradiated with a pulse-periodic YAG : Nd3+ laser is presented. The laser operates at a pulse width of 20 ns and provides 1-2 x 10(9) W/cm(2) at the focus. The spectral and time characteristics of the emission are examined. The main findings are as follows: (1)The strongest lines correspond to the transitions from the 6(3)S(1) and 5(3)D(2) levels of Cd I. (2) With the Cd target, the recombination bottlenecks are 5(2)D(5/2) of Cd II (E-up = 20. 11 eV) and 8(3)D(1),(3) of Cd I (E-up = 8.60-8.65 eV). (3) The average electron temperature outside the core of the plume is 0.64 eV. (4) For the 508.6-nm line of Cd I, the high filling rate of the 6(3)S(1) upper energy level may be related to the rapid recombination of cadmium ions with electrons via the intermediate levels of Cd- at 6.82 and 7.24 eV. (C) 2001 MAIK "Nauka/Interperiodica".