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Updated: May 10, 2026
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Characterization of SiN Integrated Optical Phased Arrays on a Wafer-Scale Test Station
Published on: April 1, 2020
A comprehensive procedure for characterizing arbitrary azimuthally symmetric photon beams
Ahad Ollah Ezzati1, Mostafa Sohrabpour1, Seied Rabi Mahdavi2
1Department of Energy Engineering, Sharif University of Technology, Tehran, Iran.
Summary
A new Monte Carlo source model (SM) for photon beams offers improved accuracy and faster simulations. This advanced model enhances dose calculations in radiation therapy, achieving results within 2% of maximum dose compared to original phase space files.
Area of Science:
- Medical Physics
- Computational Physics
- Radiation Oncology
Background:
- Monte Carlo (MC) simulations are crucial for accurate dose calculations in radiation therapy.
- Existing source models (SMs) often have limitations in accounting for particle energy dependence and accelerator components.
Purpose of the Study:
- Develop and validate a novel MC source model (SM) for azimuthally symmetric photon beams.
- Improve the accuracy and efficiency of MC simulations in radiation therapy.
Main Methods:
- Developed a new MC source model (SM) categorizing particle tracks as multiple point source (MPS) or spatial mesh based surface source (SMBSS).
- Validated the SM using MCNPX2.6 to generate phase space files (PSFs) for a 6 MV photon beam.
- Calculated percentage depth doses (PDDs) and beam profiles for various field sizes.
Main Results:
- The new SM demonstrated agreement within 2% of maximum dose at 100 cm SSD and 2.5% at 200 cm SSD compared to the original PSF.
- Out-of-field dose differences were less than 0.5% of the profile maximum.
- Calculated points showed agreement within 2% of maximum dose or 2 mm distance to agreement (DTA) with measured data.
Conclusions:
- The novel SM uniquely incorporates energy-dependent particle directionality and is independent of accelerator components.
- The model is applicable to any arbitrary azimuthally symmetric beam.
- Source biasing capabilities significantly enhance simulation speed (up to 3300x).
