Propagation of fast charged particles along a nanotube

Carbon nanotubes and fullerites in high-energy and X-ray physics

“…It happens when the charged particles can cross the cylinder surface or approach close to it. The absence of the second integral of motion leaves the door open to the phenomenon of the dynamic chaos when, together with the regular radial oscillations described above, some part of the particles can be involved in extremely irregular transverse motions as first pointed out in [51]. The manifestation of the dynamic chaos in channeling is illustrated in Fig.…”

Orientation dependence of the probability of close collisions during passage of high-energy negatively charged particle through a bent crystal

“…In the article [7] it was shown that the probability of such close collisions for high-energy negatively charged particle moving in a straight crystal increases with the decrease of w in due to axial channeling if w in < w c , where w c is a critical angle of axial channeling [5]. In the work [8] the analysis of the probability of close collisions of high-energy positively charged particle in a bent crystal as a function of the angle w in was done.…”

Angular distribution of radiation by relativistic electrons in a thin crystal

“…In this case the magnitude of the root-mean-square scattering angle of the electrons can exceed substantially (by several times) the corresponding parameter for the electron scattering in the amorphous target of the same thickness [5], and the smaller is the target thickness, the greater is this difference. This shows the existence of a coherent effect in electron scattering when the electron sequentially collides with the lattice atoms located along a given crystallographic axis.…”

“…The analytical description of the particle dynamics can be conducted only in some limiting cases. Thus, for example, the theory of multiple scattering of relativistic charged particles on atomic strings of a crystal, based on the continuous string approximation, describes the coherent azimuthal scattering of above-barrier electrons ("doughnut scattering" effect) [5,10]. However, this theory does not describe transitions of particles between two different fractions of the electron beam in the crystal, since the continuous string approximation does not take into account incoherent scattering.…”

“…In this case there is a suppression of coherent bremsstrahlung. In [4] it was noted that the condition of the LPM effect in crystal can be fulfilled at a smaller energy of the projectile particles than in an amorphous matter, because the multiple scattering in a crystal has a coherent character ("doughnut scattering" effect) and the root-mean-square angle of the multiple scattering cr ϑ can exceed significantly the corresponding value for an amorphous target of the same thickness [5]. A crystal is also suitable for study the LPM effect due to the additional possibility to change the efficiency of multiple scattering by changing the orientation angle ψ instead of the thickness changing as in the amorphous target case.…”