Determination of energy loss of 1200Â keV deuterons along axial and planar channels of Si

In this paper, the energy loss of 1200 keV deuterons along the <1 0 0> and <1 1 0> axes as well as the {1 0 0} and {1 1 0} planes of Si were determined by the simulation of the channeling Rutherford backscattering spectra. The simulation was done by taking two considerations into account: (i) a minimum random component of the beam which enters the sample because of the scattering ions from the surface, (ii) the dechanneling starts at greater penetration depths, xDech. Moreover, it was assumed that the dechanneling follows a Gompertz type sigmoidal function with two parameters k and xc which present the dechanneling rate and range, respectively. The best simulation parameters, penetration depth at which the dechanneling starts, energy loss and dechanneling rate and range, were chosen by using the Levenberg-Marquardt algorithm. The experimental results are well reproduced by this simulation. The ratio of channeling energy loss to the random is changed from 0.63 ± 0.02 along the <1 1 0> axial channel to the 0.91 ± 0.02 along the {1 0 0} planar direction. The differences in the energy loss and the dechanneling process along the axial and planar channels are attributed to the potential barrier and the fractional area of each channel blocked by atoms. The ratio of channeling to random energy loss of deuterons along the <1 0 0> axial direction is in agreement with another reference.