Measurements of Proton Channeling Energy Losses in Silicon in the Intermediate Energy Region

Abstract

on the occasion of his 80th birthdayThe energy loss of protons in the energy region from 40 to 350 keV is measured for (110), (loo), and (1 11) planar channeling, for ( l l O > , (11 l}, (1 12> axial channeling, and for random directions in silicon. The investigations are carried out by means of the transmission experiment using silicon targets of several thicknesses. Stopping power values are derrved from the peak and the leading edge of energy spectra for channeled particles. Special procedures are applied to correct the obtained stopping power data with respect to the target thickness. In the case of leading edge the stopping power data depend strongly on the target thickness. It is shown that only the extrapolation to zero thickness leads to correct stopping power values for best channeled particles. It is found that the ratio of channeled to random stopping power shows a maximum in the energy region a t about 70 keV. Here the stopping power for channeling and random directions reach their largest value, too. I n der vorliegenden Arbeit werden die Energieverluste von Protonen im Energiebereich von

Shell Structure Potential for Channeling in Solids

“…The agreement with earlier more detailed numerical calculation [14] which do not yield usable analytical expressions, was found to be good as We have calculated proton channeling energy losses in silicon (in all cases we calculated the stopping power for the best channeled particles (0 = 0)) in the intermediate energy region (40 to 300 keV) and compared them with experimental results [15]. This is shown in Fig.…”

Monte Carlo Simulation Analysis of Proton‐Energy Spectra for Axial Channeling in Silicon in the Intermediate Energy Region

“…stopping maximum is observed. An experimental verification of this prediction was given for He ions [12] and protons [9], but a quantitative agreement between theory and experiment -h -~---r calculations are presented in Table 1. It can be seen that the calculated ratios was not observed [9].…”

“…We have compared the calculated results for the total random stopping power (average over all incidence directions) with experimental data [9]. As shown in Fig.…”

“…In comparing calculations in this experimental values [9], --~ ~ -LWSM calculations model with experimental values the energy straggling of channeled particles and the energy resolution of the analyzing system should be taken into account.…”

“…Therefore, in this paper a detailed analysis of these experimental results [9] is performed by Monte Carlo calculations. The energy spectra were calculated for conditions close to the experimental ones for the axial channels (llO), ( l l l ) , and <112).…”