Photon production at the interaction point of the ILC

TL;DR

This paper simulates photon production at the ILC interaction point due to beam-beam effects, providing critical data for machine design and photon management strategies.

Contribution

It offers detailed simulation results of photon production rates and distributions for various ILC beam parameters, including cone definitions for safe photon transport.

Findings

Photon cone half-opening angles of 0.75 and 0.85 mrad suggested

Simulations cover all machine energies and parameters

Comparison with theoretical expectations confirms results

Abstract

The intense beam-beam effect at the interaction point of the International Linear Collider (ILC) causes large disruption of the beams and the production of photons. These photons, arising dominantly through beamstrahlung emission, are problematic for the machine design as they need to be transported and dumped in a controlled way. In this work, we perform simulations of the beam-beam interaction to predict photon production rates and distributions for the different beam parameters considered at ILC. The results are expressed in terms of a set of cones of excluded power, allowing to define the beam-stay-clear requirements relevant for different cases and contexts. A comparison is also made with theoretical expectations. The suggested photon cone half-opening angles are 0.75 and 0.85 mrad in the horizontal and vertical planes, respectively. These cones cover all machine energies and parameter sets, and include the low power Compton photons.