Measurement of the Energy of Nitrogen Ions Produced in Filippov Type Plasma Focus Used for the Nitriding of Titanium

Abstract

In this paper the nitrogen ion properties (maximum energy, current density and the most probable energy) are investigated by using Faraday cup in a time of flight method. These ions are produced in a Filippov type plasma focus (Sahand Facility) device and the Faraday cup was placed in a distance range of 18–24 cm from the top of the anode. Maximum and minimum most probable ion energies are 76 and 8.5 keV for the distance range of 18 and 24 cm, respectively. The displacement from 18 to 24 cm at top of the anode the ion current density varies from 4.5 × 10⁶ to 3.2 × 10⁵ (A m⁻²). For the investigation of the effect of ions bombardment of materials at different positions, at the optimum working conditions of 14 kV as a working voltage, and 0.25 Torr as a gas pressure, titanium samples are placed in a distance of 21, 22, 23 and 24 cm from the top of the anode (θ = 0) and each sample is put under irradiation for 30 plasma shots. The structure of the nitrided surfaces and their morphologies are characterized by X-ray diffractometry and by scanning electron microscopy, respectively. The average crystallite size deduced for (200) and (222) planes of TiN deposited with 30 shots in different distances are estimate to be from ~13 to ~38 nm.