Evaluation and compensation of detector solenoid effects on disrupted beam in the ILC 14 mrad extraction line

Abstract

This paper presents analysis of detector solenoid effects on primary disrupted beam in the ILC 14 mrad extraction line and their compensation. Particle tracking simulations are performed for evaluation of the extracted beam loss as well as of beam distribution and polarization at Compton interaction point (IP). The calculations are done both without and with compensation of the solenoid induced perturbations: the residual orbit, dispersion and focusing. The proposed correction system includes a detector integrated dipole field and a set of dipole and quadrupole correctors. This system effectively minimizes the growth of particle amplitudes induced by the solenoid; and therefore it keeps at minimum the corresponding growth of beam loss and helps to maintain the design beam properties at Compton IP for polarization measurement. The presented results are obtained for the baseline ILC energy of 500 GeV center-of-mass and three options of initial beam parameters.