Experimental investigation and simulation of penetration depth of nitrogen ions emitted by plasma focus device inside titanium samples

Abstract

The plasma focus device is a simple, inexpensive, and precious device that can be considered as a source of high-energy ions for researches relevant to interactions of ions with widely used materials such as titanium. Regarding exclusive properties such as a high degree of hardness and resistance to corrosion, titanium nitride alloy is considered to be one of the most essential materials with a wide range of industrial applications. In the present study, the characteristics of titanium nitride alloys were studied using a 1.5 kJ Mather-type plasma focus device. To do this, a Faraday cup detector is used to measure the current density of the ion beam in order to determine the energy spectrum of nitrogen ions using time of flight approach. The optimal operational condition of the device for nitrogen ions emission, in terms of gas pressure and voltage of discharge were also determined. Titanium samples were situated on the top of the anode of the device and were exposed to nitrogen ion radiation considering 5, 10, and 20 shots of the device. To simulate the penetration depth of nitrogen ions inside the titanium samples, the SRIM code is used. The obtained energy of ions from the time of flight technique was set as input of the SRIM code, and it was found that nitrogen ions, with an average energy of 50 keV can penetrate about 110 nm inside the titanium sample. It was understood that the finding results of the penetration depth are in good agreement with the SEM micrographs of the titanium samples. The sputtering yield of titanium atoms was determined using the SRIM simulation code, and it was found that the yield of the surface of the samples is less than 0.2 atoms per individual nitrogen atom.

Keywords

• Plasma focus device
• Ion implantation
• Titanium nitride
• Faraday cup
• SRIM code