EGS (program)

EGS, often expanded as EGSnrc, stands for Electron Gamma Shower. It is a Monte Carlo code system used for simulating the transport of electrons and photons in matter. Developed primarily at the National Research Council of Canada (NRC), EGSnrc is a widely recognized and used tool in radiation physics, medical physics, and related fields.

EGSnrc simulates the interactions of electrons and photons as they travel through various materials. It tracks these particles and their secondary particles (such as bremsstrahlung photons and delta electrons) through their individual interactions, taking into account a wide range of physical processes including Compton scattering, photoelectric effect, pair production, bremsstrahlung, and ionization.

The EGSnrc code is based on the EGS4 code but incorporates numerous improvements and features, including enhanced accuracy, improved efficiency, and easier user interface. It allows for the simulation of complex geometries using various geometry packages included with the code or that can be integrated.

Key features and applications of EGSnrc include:

• Radiation Transport: Simulates the transport of electrons and photons across a wide energy range.
• Medical Physics: Used extensively for radiation therapy planning, dosimetry calculations, and imaging simulations.
• Nuclear Physics: Applications in detector design, shielding calculations, and fundamental research.
• Industrial Applications: Used in industrial radiography, non-destructive testing, and other applications involving radiation.
• Materials Science: Can be used to study the interaction of radiation with materials, including damage and activation.
• Monte Carlo Simulation: Employs Monte Carlo methods to stochastically simulate particle interactions.
• Geometry Packages: Supports various geometry packages for defining complex simulation geometries.

EGSnrc is distributed freely for non-commercial purposes and requires a license. The EGSnrc system includes various user codes, libraries, and tools for preparing input files, running simulations, and analyzing the results. The software relies on cross-section data to model the interactions of particles with matter. These data are updated periodically to improve the accuracy of simulations. Understanding the physics behind the Monte Carlo simulation and the specific geometry and materials being modeled is essential for obtaining reliable results.