Results from the EPICAL-2 Ultra-High Granularity Electromagnetic Calorimeter Prototype

TL;DR

This paper presents the development and testing of a novel silicon-tungsten electromagnetic calorimeter prototype with digital pixel sensors, demonstrating promising energy resolution, linearity, and shower separation capabilities through cosmic and test beam experiments.

Contribution

The paper introduces a new silicon-tungsten calorimeter prototype using pixel sensors with digital readout, tested with cosmic rays and test beams, showing promising performance metrics.

Findings

Good energy resolution and linearity at DESY

Successful demonstration of shower separation capabilities

Preliminary high-energy performance results at CERN SPS

Abstract

A prototype of a new type of calorimeter has been designed and constructed, based on a silicon-tungsten sampling design using pixel sensors with digital readout. It makes use of the Alpide MAPS sensor developed for the ALICE ITS upgrade. A binary readout is possible due to the pixel size of $\approx 30 \times 30 \, \mu \mathrm{m}^2$. This prototype has been successfully tested with cosmic muons and with test beams at DESY and the CERN SPS. We report on performance results obtained at DESY, showing good energy resolution and linearity, and compare to detailed MC simulations. Also shown are preliminary results of the high-energy performance as measured at the SPS. The two-shower separation capabilities are discussed.