We performed first-principles (DFT) calculations to estimate the secondary emission yield (SEY) through the Auger neutralization mechanism (γ^N) related to the impact of a series of ions on a polyethylene surface. We considered many relevant ionic species, such as Ar⁺, which is often used as a benchmark. Our main objective is to study dielectric surfaces; however, to verify the validity of our approach, we also took into consideration some metallic surfaces (Al, Cu, Cu:N, Cu:O and CuO) for which other experimental data can be found. In contrast, very few references are available relating to drill neutralization on insulating materials and, in particular, on polyethylene.

The SEY results for metals essentially reproduced the experimental references. In particular, the same decrease in γ^N, which was associated with a “dirty” metal surface (exposed to gases), was confirmed by the calculations. Therefore, the applicability of the method to plastic material was considered to give realistic results. The calculated γN values associated with polyethylene are of the order of 10 sup>-1 for most of the ionic species considered here. Furthermore, we observed that a few percentage points of change in surface energy levels predicted by DFT calculations can cause, depending on the type of ion, a substantial variation in γ^N. Therefore, a detailed sensitivity analysis was included to address this issue. The results associated with metals showed that the variations in γ^N are, for some types of ions, very clear, while variability is milder for a polyethylene surface. Our calculations are fully compatible with previous literature on the subject and suggest that plastic materials are characterized by γ^N similar to those of only slightly smaller metals.