Influence of incoherent scattering on stochastic deflection of high-energy negative particle beams in bent crystals

I V Kirillin,N F Shul’Ga,A Mazzolari,V Guidi,L Bandiera

doi:10.1140/epjc/s10052-017-4694-z

Abstract

An investigation on stochastic deflection of high-energy negatively charged particles in a bent crystal was carried out. On the basis of analytical calculation and numerical simulation it was shown that there is a maximum angle at which most of the beam is deflected. The existence of a maximum, which is taken in the correspondence of the optimal radius of curvature, is a novelty with respect to the case of positively charged particles, for which the deflection angle can be freely increased by increasing the crystal length. This difference has to be ascribed to the stronger contribution of incoherent scattering affecting the dynamics of negative particles that move closer to atomic nuclei and electrons. We therefore identified the ideal parameters for the exploitation of axial confinement for negatively charged particle beam manipulation in future high-energy accelerators, e.g., ILC or muon colliders.

Highlights

IntroductionAs for planar channeling, the contribution of incoherent scattering plays a crucial role in the dynamics of negative particles moving in a crystal in the regime of stochastic deflection
The existence of a maximum, which is taken in the correspondence of the optimal radius of curvature, is a novelty with respect to the case of positively charged particles, for which the deflection angle can be freely increased by increasing the crystal length
We determined the ideal parameters for exploitation of stochastic deflection as a tool for negative high-energy beam manipulation in accelerators

Summary

Introduction

As for planar channeling, the contribution of incoherent scattering plays a crucial role in the dynamics of negative particles moving in a crystal in the regime of stochastic deflection. The role of incoherent scattering in stochastic deflection has never been deepened. We investigated the incoherent scattering contribution in the stochastic deflection of negatively charged particles by means of analytical calculation and Monte Carlo simulation. We analyzed the dependence of the deflection efficiency from the crystal radius of curvature, defining an optimal radius of curvature. A possibility for exploitation of stochastic deflection in electron beam collimation was examined

Analytical model for stochastic deflection of negative particles

Monte Carlo simulations and discussion

Conclusions