[Prex] Evaluation of beam halo from beam-gas scattering at the KEK Accelerator Test Facility

[Jay Benesch]

https://journals.aps.org/prab/abstract/10.1103/PhysRevAccelBeams.21.051001

R. Yang, T. Naito, S. Bai, A. Aryshev, K. Kubo, T. Okugi, N. Terunuma, 
D. Zhou, A. Faus-Golfe, V. Kubytskyi, S. Liu, S. Wallon, and P. Bambade
Phys. Rev. Accel. Beams 21, 051001 – Published 23 May 2018

In circular colliders, as well as in damping rings and synchrotron 
radiation light sources, beam halo is one of the critical issues 
limiting the performance as well as potentially causing component damage 
and activation. It is imperative to clearly understand the mechanisms 
that lead to halo formation and to test the available theoretical 
models. Elastic beam-gas scattering can drive particles to large 
oscillation amplitudes and be a potential source of beam halo. In this 
paper, numerical estimation and Monte Carlo simulations of this process 
at the ATF of KEK are presented. Experimental measurements of beam halo 
in the ATF2 beam line using a diamond sensor detector are also 
described, which clearly demonstrate the influence of the beam-gas 
scattering process on the transverse halo distribution.