On the influence of periodicity in the arrangement of crystalline atomic strings upon the spectral and spectral-angular distribution of high-energy positively charged particle radiation in crystal

Spectral and spectral-angular distribution of the radiated energy in case of positron motion in an oriented crystal and in case of positron motion in the field of randomly located atomic strings (random strings approximation) when the angle between particle momentum and crystal axes is less than the critical angle of axial channeling were calculated. Obtained results showed that the peak in the emission spectrum is related to the quasi-regular motion of the above-barrier positrons in planar channels.