抄録
The intensity of the forbidden 222-reflection of electrons from germanium at the Bragg position is calculated as the function of the crystal thickness by means of three kinds of approximation, i.e. (1) exact solution in the harmonic potential corresponding to the 111-Fourier potential, (2) Feynman expansion of the scattering matrix for the harmonic potential taking account of the influence of the 333-Fourier potential, and (3) expansion of the scattering matrix taking account of the three waves (000), (111) and (222).
The integrated intensities of the 222-reflection due to systematic interactions and the 200-reflection due to accidental interactions are also calculated by the expansion of the scattering matrix. The results show that the ratio of the integrated intensity of the 222-reflection to that of the 111-reflection is proportional to the square of crystal thickness and of wave length, and the ratio of the integrated intensity of the 200-reflection to that of the 222-reflection is independent of wave length.
