Initial performance assessment and calibration techniques of the production monolithic silicon pixel detector ASIC for the detection of electromagnetic showers of TeV energy in the FASER experiment at the LHC

TL;DR

This paper reports on the initial performance assessment and calibration techniques for a monolithic silicon pixel detector ASIC designed for detecting TeV electromagnetic showers in the FASER experiment at the LHC, demonstrating promising operational results.

Contribution

It introduces a new monolithic silicon pixel ASIC for high-energy photon detection and presents calibration methods for accurate charge reconstruction in the FASER experiment.

Findings

ASIC components operate as expected in initial tests

Two calibration methods successfully reconstruct charge from ADC values

The detector design enhances photon pair separation at TeV energies

Abstract

The FASER experiment at the LHC aims to detect new, long-lived fundamental particles. A tungsten-silicon (W-Si) preshower detector is being developed to enhance the experiment's ability to distinguish between closely spaced photon pairs with energies on the order of TeV and separations as small as 200 \textmu m. This detector will use a monolithic silicon pixel sensor fabricated with 130 nm SiGe BiCMOS technology. Initial tests were conducted on the production ASIC, after evaluating the performance of the preproduction one. The first tests on the production ASIC indicate that the essential components of the monolithic silicon pixel detector are operating as expected. Two calibration methods were developed to reconstruct the charge of the FASER preshower detector, from the ASICs' ADC values.