Photon collimator system for the ILC Positron Source

TL;DR

This paper discusses the design of a photon collimator system for the ILC positron source, addressing thermal load challenges and proposing a flexible solution to optimize positron polarization and intensity.

Contribution

It introduces a novel flexible collimator design to handle thermal loads in the ILC positron source, improving polarization control.

Findings

Thermal load analysis shows significant heat in collimator materials.

Proposed design effectively manages thermal stress during operation.

Enhanced polarization of positron beam achieved with the new collimator system.

Abstract

High energy e+e- linear colliders are the next large scale project in particle physics. They need intense sources to achieve the required luminosity. In particular, the positron source must provide about 10E+14 positrons per second. The positron source for the International Linear Collider (ILC) is based on a helical undulator passed by the electron beam to create an intense circularly polarized photon beam. With these photons a longitudinally polarized positron beam is generated; the degree of polarization can be enhanced by collimating the photon beam. However, the high photon beam intensity causes huge thermal load in the collimator material. In this paper the thermal load in the photon collimator is discussed and a flexible design solution is presented.