GDCP: A custom package for flexible detector setups in Geant4

TL;DR

GDCP is a C++ package that simplifies and enhances the flexibility of detector construction in Geant4, especially for complex setups involving optical components, by applying the Builder design pattern.

Contribution

The paper introduces GDCP, a new C++ package that implements the Builder design pattern to improve the flexibility and maintainability of Geant4 detector construction code.

Findings

Facilitates development of complex detector setups in Geant4.

Provides helper classes for optical component implementation.

Demonstrates utility through an advanced Geant application.

Abstract

Geant4 Detector Construction Pattern (GDCP) is a C++ package containing a set of utility classes for developers to utilize during the detector construction phase of a Geant4 application. The main objective of this study is to provide an interface that helps users develop a highly flexible, understandable, and maintainable detector construction code. The package also contains a couple of helper classes facilitating the implementation of optical components in scintillation detectors. Finally, an advanced Geant application has been provided to demonstrate the package's utility. Program summary Program title: GDCP CPC Library link to program files: Licensing provisions: GNU General Public License 3 Programming language: C++ External routines/libraries: Geant4 Nature of problem: Geant4 provides an abstract class, G4VUserDetectorConstruction, that is used for the whole detector construction. This is sufficient for a simple detector setup but implementing a single class for building a complex detector leads to complexity in the code. To solve this issue it is recommended to split the implementation into more methods or classes; however, there is no standard solution published yet and it is entirely left to the users' ability. Solution method: To address this issue, I propose to apply the "Builder design pattern" in the detector construction phase. For this, the elements of the Builder design pattern have been introduced and made available for developers. Keywords: G4VUserDetectorConstruction, Builder design pattern, Detector construction, Component builder, Optical photon, Scintillator