Instrumentation of the Very Forward Region at Future Linear Colliders - design and R&D by the FCAL Collaboration

TL;DR

This paper discusses the design and R&D of two compact, highly segmented calorimeters for the very forward region of future linear colliders, focusing on precision measurements, radiation hardness, and fast electronics.

Contribution

It presents the design, R&D, and performance results of sensor and electronics prototypes for forward calorimeters at ILC and CLIC.

Findings

Sensor and readout electronics prototypes meet performance requirements.

Radiation-hard sensors are effective for high beamstrahlung environments.

Fast electronics enable high occupancy handling.

Abstract

Two finely segmented and very compact calorimeters are foreseen for the instrumentation of the very forward region of the ILC and the CLIC detectors; a luminometer to measure the rate of low angle Bhabha scattering events with a precision better than $10^{-3}$ and, at lower polar angles, a detector for fast luminosity estimate. Both devices will improve the hermeticity of the detector in searches for new particles. Due to the expected high occupancy, fast front-end electronics is needed. The calorimeter closest to the beampipe will be hit by a large amount of beamstrahlung remnants, so that radiation hard sensors are required. Results on the performance of the sensor and readout electronics prototypes are summarized.