BEAMnrc: software tool to model radiation beams

Overview of the software

The BEAMnrc system can meet your specific requirements relating to modelling beams of electrons and photons travelling through consecutive material components, ranging from simple slabs to complex collimators. BEAMnrc is built around the core EGSnrc Monte Carlo simulation software for radiation transport.

The main application for BEAMnrc is modelling the treatment head of radiotherapy linear particle accelerators (linacs) used by medical physicists to treat cancer. Due to its flexible, modular design and companion utilities, this software can also be used for a vast range of applications, including the simulation of research and industrial linac beams, x-ray emitters, radiation dose delivery to a patient, radiation shielding, and more.

NRC also trains Canadian and international physicists on use of the software.

NRC’s involvement in the development and application of the Monte Carlo method in the modelling of radiation beams dates back to the early 1990s. The BEAMnrc software is now downloaded more than 2,000 times per year by academic, medical and industrial researchers worldwide.

Targeted audience

  • Medical physicists, universities and hospitals.
  • Companies that develop radiotherapy equipment and software.
  • Universities and industries working with radiation, including radiation measurement, radiotherapy, radiation protection, radiation processing, medical imaging, and other electron and photon radiation applications.

Description of the software

BEAMnrc is a user-code generator for EGSnrc. It draws from a collection of pre-built component modules to compile a final program corresponding to the linac or device of interest. A rich graphical user interface is provided to set simulation parameters for the beam and each component at run time.

The BEAMnrc package includes the dose scoring utility DOSXYZnrc to estimate radiation dose in a voxel geometry, such as patient medical imaging data. It also includes data processing tools to analyze the beam characteristic in detail and plot dose profiles and dose contours.

BEAMnrc is an improved and EGSnrc-compatible version of the original BEAM package developed by NRC and the University of Wisconsin-Madison in the 1990s (DWO Rogers et al. BEAM: A Monte Carlo code to simulate radiotherapy treatment units. Medical physics 22, 1995).

System requirements

BEAMnrc works on GNU/Linux, Unix, Mac OS X and Windows. It consists of a set of component module source files and utilities to quickly build EGSnrc Monte Carlo user codes for radiation beam simulations. As such, it is not stand-alone software and requires the following:

  • EGSnrc
  • A Fortran compiler
  • The GNU make utility
  • The Tcl/Tk interpreter and GUI tookit
  • Grace (to display results graphically)


BEAMnrc is trusted by researchers worldwide for simulation accuracy and speed, and is widely regarded as the most accurate computer program for the simulation of electron and photon beams. The BEAM code has been used extensively by medical physicists over the past two decades, resulting in hundreds of publications in scientific journals. Through this rigorous peer-review process it has evolved into a reliable and well-benchmarked software. Commercial partners around the world also rely upon BEAMnrc for the design of radiation equipment and software, as is evidenced by commercial license agreements that are already in place.


The software is freely available for research and other non-commercial purposes. Please read the full license agreements before downloading. Companies should contact NRC to obtain a commercial licence for the software.


For technical inquiries

Dr. Frédéric Tessier
Telephone: 613-993-9352 ext. 237

Dr. Ernesto Mainegra-Hing
Telephone: 613-993-9352 ext. 260

For business inquiries