Photoneutron dose and flux determination of a typical LINAC by MCNP simulation

Purpose High-energy electron linear accelerators (LINACs) have a wide use in radiotherapy. The photoneutron production in medical linear accelerators, when operating at energies greater than 10 MeV, is an important subject to consider in patient's treatment procedures. In this work, we simulate a typical LINAC to calculate photoneutron dose and flux in radiotherapy room. Methods The latest version of MCNPX Monte Carlo code along with MCNP visual editor has been used to simulate the LINAC and its components. Photoneutron production has been successfully simulated by selecting appropriate physics card and parameters. Dose and flux of produced photoneutrons have been calculated by using mesh tally function. Results Production of photoneutrons in LINAC head and its components have been successfully simulated by using MCNPX code. MCNP visual editor has been used to track the particles. Photoneutron dose and flux have been calculated using mesh tally function, with good results of statistical tests. Conclusion The photoneutron production has been successfully simulated and benchmarked. The proposed simulation code is able to calculate photoneutron dose and flux. According to photoneutron production cross sections, the appropriate parameters have been selected to reduce the run-time of simulation code.

Automated summary

This study successfully simulated the production of photoneutrons and calculated the dose and flux of photoneutrons in the LINAC head and its components using MCNPX code. By selecting appropriate physics parameters, the simulation code efficiency was improved.