Production of current and ion beams on a copper surface by laser radiation of various wavelengths under the presence of an applied electric field

A Copper (Cu) target kept under partial vacuum conditions (10− 3 mbar) irradiated with focused first-four harmonics of a Q-switched Nd:YAG laser radiation at wavelengths of 1064, 532, 355 and 266 nm with pulse duration 7, 6, 7 and 6 ns, respectively. The evaporated ions were detected at a distance of 40 mm away from the target, after having passed through the retarding mesh grid (Cu electrode). The laser radiation with peak intensity between 4.6 × 109 and 1.3 × 1011 W/cm2 creates a dense plasma having high ionization state. This paper presents generation and detection of highly stripped Cu ions and high current in laser produced plasma. The velocity distribution function of the plasma cloud which emitted from the Cu target flare is investigated by using a Faraday cup technique. The dependence of the current signals on various parameters, such as laser power, laser wavelengths and argon (Ar) pressure, is described. In general, a sharp increase in the plume current was observed as the voltage is increased and is related to arc formation.