Modified Dechanneling Theory and Diffusion Coefficients

Diffusion coefficients in channeling

“…From our exact calculation of the diffusion coefficient making use of Ohtsuki's expression (l), (2) and ( 3 ) , we noted that the Lindhard expressions for nuclear and single-electron excitations are not good analytic form. Figure 1 shows that the analytic expression proposed in previous paper by Kitagawa and Ohtsuki is a good one.…”

Simulation of orientational effects in crystals with structural defects through DYNECHARM++

“…In order to account for the contribution of a interstitial defect, DYNECHARM++ computes a different integrated probability of incoherent scattering (r sc;d ) as the standard integrated probability of single scattering (r sc ) multiplied by the ratio between the volumetric density of defect (n d ) and the density of atoms in the crystal (n a ). Because particles under coherent effect interact with a different quantity of matter depending on their trajectories in the crystal [17], Monte Carlo simulations have to take account of the variation of the cross section as a function of the particle trajectories to correctly reproduce experimental data [18,19]. Since the interstitial defects are usually located between the atomic lattice nuclei, the integrated probability is scaled by the normalized q d interstitial defect density averaged over the particle trajectory [20,21].…”

A model for the interaction of high-energy particles in straight and bent crystals implemented in Geant4

“…Thus, the probability of interaction with nuclei and electrons has to be weighted as a function of the transverse energy. Kitagawa and Ohtsuki [71] demonstrated that there is a linear dependence between the incoherent interaction rate and the material density. Therefore, the modified cross section σ (E t ) of each phenomenon is…”