Diagnose and investigation of angular distribution of copper plasma ions

Abstract

A q-switched nd:yag laser with fundamental wavelength of 1064 nm delivering pulse energy of 125 mj and pulse duration of 8 ns was employed as a source of energy to generate plasma. The laser was focused on copper as a target material. The angular distribution of ejected ions species were collected by a developed faraday cup. The cups were arranged radialy at the range of angles from 5o to 90o with two radiuses of 5 cm and 10 cm. The cups were coupled to high speed oscilloscope to display and measure the ion flux and charge state. The exposed faraday cup was also studied by metallurgical technique. The results obtained show that the maximum flux of copper ion collected by faraday cup was 11.7 x 1016 charge /sec. The maximum number of charge state was cu+4 at 5 cm and cu+3 at 10 cm. In general the angular distribution of ions flux is maximum in axial direction and decreases in radial direction. The temperature and density of copper is measured with electronic probe. Various elements are found deposited on faraday cup with majority lines of copper cluster