Channeling 2012

Multiple Scattering and Volume Capture of Charged Particles in Bent Crystals

25 Sept 2012, 12:00

15m

Hotel Calabona (Hotel Calabona)

Channeling & Crystal Collimation S3.2 Channeling & Crystal Collimation

Speaker

Dr Micola Bondarenco (Kharkov Institute of Physics and Technology)

Description

Recent results [1] on incoherent multiple scattering for charged particles passing through bent crystals in planar orientation are surveyed. Regions in the crystal bending radius vs. particle energy ($R$, $E$) plane are determined, where: i- the number of bent atomic planes crossed by the particle within the intrinsic volume reflection region of extent $\sim R{\theta }_c$ is greater than 1; ii- the influence of thermal spread $u(T)$ of atomic nuclei in the crystallographic planes on the interplanar potential is negligible; iii- multiple scattering angles acquired in the intrinsic volume reflection region are small compared to the Lindhard's critical angle ${\theta }_c$; iv- the volume capture probability is small. Intersection of those regions gives optimal conditions for beam steering by volume reflection. The estimates for volume capture indicate that it must occur predominantly as a result of scattering in the bent plane closest to the radial reflection point. Thereat, the volume capture probability obeys the scaling law [1] \[ P_{\text{capt}}\propto \frac{R}{u^{1/2}(T)E^{3/2}}. \] References [1] M.V. Bondarenco, Phys. Rev. ST-AB 15 (2012) 032802.