A Quartz Cherenkov Detector for Compton-Polarimetry at Future e+e- Colliders

TL;DR

This paper presents the design, simulation, and initial testing of a quartz Cherenkov detector aimed at achieving high-precision Compton polarimetry for future e+e- colliders, focusing on minimizing systematic uncertainties.

Contribution

It introduces a novel quartz Cherenkov detector design with single-peak resolution capabilities for improved polarisation measurement accuracy.

Findings

Simulation shows detectable individual Cherenkov photon peaks for different electron counts.

Prototype tests confirm the detector's ability to resolve single electrons as predicted.

The detector design reduces systematic uncertainties in polarisation measurements.

Abstract

Precision polarimetry is essential for future e+ e- colliders and requires Compton polarimeters designed for negligible statistical uncertainties. In this paper, we discuss the design and construction of a quartz Cherenkov detector for such Compton polarimeters. The detector concept has been developed with regard to the main systematic uncertainties of the polarisation measurements, namely the linearity of the detector response and detector alignment. Simulation studies presented here imply that the light yield reachable by using quartz as Cherenkov medium allows to resolve in the Cherenkov photon spectra individual peaks corresponding to different numbers of Compton electrons. The benefits of the application of a detector with such single-peak resolution to the polarisation measurement are shown for the example of the upstream polarimeters foreseen at the International Linear Collider. Results of a first testbeam campaign with a four-channel prototype confirming simulation predictions for single electrons are presented.