Allpix2: A modular simulation framework for silicon detectors

Abstract

Allpix 2 (read: Allpix Squared) is a generic, open-source software framework for the simulation of silicon pixel detectors. Its goal is to ease the implementation of detailed simulations for both single detectors and more complex setups such as beam telescopes from incident radiation to the digitised detector response. Predefined detector types can be automatically constructed from simple model files describing the detector parameters.The simulation chain is arranged with the help of intuitive configuration files and an extensible system of modules, which implement separate simulation steps such as realistic charge carrier deposition with the Geant4 toolkit or propagation of charge carriers in silicon using a drift-diffusion model. Detailed electric field maps imported from TCAD simulations can be used to precisely model the drift behaviour of charge carriers within the silicon, bringing a new level of realism to Monte Carlo based simulations of particle detectors.This paper provides an overview of the framework and a selection of different simulation modules, and presents a comparison of simulation results with test beam data recorded with hybrid pixel detectors. Emphasis is placed on the performance of the framework itself, using a first-principles simulation of the detectors without addressing secondary ASIC-specific effects.

Smartphone and Tablet-Based Sensing of Environmental Radioactivity: Mobile Low-Cost Measurements for Monitoring, Citizen Science, and Educational Purposes

“…Within 707 min, 906 pulses are recorded corresponding to a count rate of 1.28 cpm: distinctively higher than the average background rate of 0.06 cpm with this detector (in a typical 0.1 μSv/h environment of low-background radiation). The simulation in Figure 7b is calculated using Allpix2, an open source simulation framework which permits simulation of a broad range of semiconducting detector setups and radiation sources [32]. It simplifies usage of the underlying Geant4 toolkit, which is a powerful but complex software for simulating a large variety of particle interactions in matter.…”

Silicon Vertex and Tracking Detector R&D for CLIC

“…For verification, the response of the sensor to a particle beam was studied in a combination of Monte Carlo (MC) and electrostatic TCAD simulations. For this purpose, electrostatic sensor simulations in 3D TCAD were imported into the Geant4-based MC framework Allpix 2 [12], thereby harnessing the full potential of the accurate sensor modelling in TCAD and the high statistics thanks to the MC approach [13].…”

R&D for the CLIC vertex and tracking detectors

“…The use of a versatile and well tested DAQ, rather than developing a device specific system each time, significantly reduces the time needed for protoype developement and testing. Allpix 2 : To better understand the behaviour of complex detectors, a modular and generic framework for Monte-Carlo simulations has been developed [16]. This comprehensive software can model detector response from incident ionising particles through to digitisation in the readout system.…”