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Sci—Sat AM: Brachy — 04: Neutron production around a radiation therapy linac bunker ‐ monte carlo simulations and physical measurements
Author(s) -
Khatchadourian R,
Davis S,
Evans M,
Licea A,
Seuntjens J,
Kildea J
Publication year - 2012
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4740211
Subject(s) - linear particle accelerator , neutron , monte carlo method , physics , electromagnetic shielding , bunker , nuclear physics , equivalent dose , neutron source , dosimetry , nuclear engineering , nuclear medicine , optics , medicine , chemistry , engineering , mathematics , coal , beam (structure) , statistics , organic chemistry , quantum mechanics
Photoneutrons are a major component of the equivalent dose in the maze and near the door of linac bunkers. Physical measurements and Monte Carlo (MC) calculations of neutron dose are key for validating bunker design with respect to health regulations. We attempted to use bubble detectors and a 3 He neutron spectrometer to measure neutron equivalent dose and neutron spectra in the maze and near the door of one of our bunkers. We also ran MC simulations with MCNP5 to measure the neutron fluence in the same region. Using a point source of neutrons, a Clinac 1800 linac operating at 10 MV was simulated and the fluence measured at various locations of interest. We describe the challenges faced when measuring dose with bubble detectors in the maze and the complexity of photoneutron spectrometry with linacs operating in pulsed mode. Finally, we report on the development of a userfriendly GUI for shielding calculations based on the NCRP 151 formalism.