# Beam test performance of the highly granular SiW-ECAL technological prototype for the ILC

## TL;DR

This paper reports on the beam test performance of a highly granular silicon-tungsten electromagnetic calorimeter prototype, demonstrating its signal quality, uniformity, and response to electrons in a controlled test environment.

## Contribution

It presents the first beam test results of the CALICE SiW-ECAL prototype, showcasing its performance metrics and response characteristics.

## Key findings

- High signal-to-noise ratio achieved
- Uniform detector response demonstrated
- Effective electron response measured

## Abstract

The technological prototype of the CALICE highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) was tested in a beam at DESY in 2017. The setup comprised seven layers of silicon sensors. Each layer comprised four sensors, with each sensor containing an array of 256 $5.5\times5.5$ mm$^2$ silicon PIN diodes. The four sensors covered a total area of $18\times18$ cm$^2$, and comprised a total of 1024 channels. The readout was split into a trigger line and a charge signal line. Key performance results for signal over noise for the two output lines are presented, together with a study of the uniformity of the detector response. Measurements of the response to electrons for the tungsten loaded version of the detector are also presented.