Precision beam telescope based on SOI pixel sensor technology for electrons in the energy range of sub-GeV to GeV

TL;DR

This paper presents a high-precision beam telescope system using SOI pixel sensors, achieving sub-10 micron tracking accuracy for electrons in the GeV range, verified through experiments and simulations.

Contribution

Development of a silicon-on-insulator pixel sensor-based beam telescope with optimized tracking precision for sub-GeV to GeV electrons.

Findings

Achieved 11.04 μm tracking precision at 822 MeV/c positrons.

Estimated 2.22 μm tracking precision for 5 GeV electrons.

Validated performance estimates with Geant4 simulations.

Abstract

We developed a beam telescope system comprising five layers of 300-$\mu$m-thick INTPIX4NA monolithic pixel sensors with each pixel size of 17 $\mu$m square. The sensors were fabricated using silicon-on-insulator (SOI) technology. The signal-to-noise ratio of 140--230 is realized at a bias voltage of 20~V. The tracker system was tested using a positron beam of 200--822 MeV/c, and various tracking methods are examined to optimize spatial precision achievable at these energies. The best tracking precision including the precision of the sensor under test itself is 11.04 $\pm$ 0.10 $\mu$m for 822-MeV/c positrons for an equidistant sensor spacing of 32 mm. The achieved precision results combined with the intrinsic spatial resolution value obtained for a similar system using 120 GeV protons are used to estimate the tracking performance of electrons in the GeV energy range; a tracking precision of 2.22 $\mu$m is evaluated for 5-GeV electrons. The method to estimate the tracking performance is verified using a Geant4-based simulation. The developed high precision tracker system enables to map the detailed performance of the sensors with pixel sizes of $\mathcal{O}$(10 $\mu$m), therefore will be a powerful system for development of devices targeting precision position resolutions.