Electrical diagnostics of laser ablated platinum plasma

The most significant parameters of laser-induced plasma are investigated here experimentally. Pure platinum targets of 4 N were irradiated both in air and under vacuum (∼10−3 Torr) by Q-switched Nd: YAG laser (1064 nm, 10 mJ, 9–14 ns, 1.1 MW). A self fabricated Langmuir probe was used as an electric diagnostic tool. Varying voltages were applied to the probe and the corresponding values of currents were recorded to draw current–voltage (I–V) characteristics curves. The electronic signals were recorded on 500 MHz DL1740, YOKOGAWA four channels digital storage oscilloscope. Different plasma characteristics like electron temperature, electron density, Debye's length, plasma frequency and numbers of particles in the “Debye's Sphere” were calculated both in air and under vacuum.