The influence of low energy titanium ion beam irradiation on secondary electron emission of metal materials by electron impact

Argon ion beams with energy from hundreds eV to several keV can suppress the secondary electron emission (SEE) on surface of metal materials by changing surface morphology and chemical composition of the materials through surface sputtering. In this work, it was found that the low-energy titanium ion irradiation with an average energy from 40 keV to 100 keV did not apparently change the surface morphology and chemical composition of the metal materials, but still significantly reduced the secondary electron yield (SEY) of the materials. Pulsed titanium ion beams generated by an ion implanter, which is based on metal evaporation vacuum arc (MEVVA) ion source, were adopted to irradiate oxygen-free copper and stainless-steel samples. The fluence of titanium ions was in the range of 1 × 10¹⁵ to 1 × 10¹⁷ ions/cm². By comparing the effects of different titanium ion energies and fluence on the roughness, chemical composition, total SEY of the sample surface, and calculating the ion range, sputtering yield, nuclear stopping power and defect distribution of titanium ions in these materials, it is reasonable to believe that the irradiation damage caused by titanium ion implantation increases the probability of trapping of the low-energy secondary electrons (SEs) by defects, leading to better SEE suppressing.