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An intercomparison of neutron measurements for a 25 MV x‐ray radiotherapy accelerator
Author(s) -
Nath Ravinder,
Price K. W.,
Holeman G. R.
Publication year - 1980
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 - 10.1118/1.594716
Subject(s) - neutron , dosimeter , monte carlo method , ionization chamber , physics , linear particle accelerator , nuclear physics , photon , bonner sphere , dosimetry , materials science , radiation , neutron temperature , beam (structure) , ionization , optics , nuclear medicine , neutron cross section , medicine , statistics , mathematics , quantum mechanics , ion
High‐energy x‐ray radiotherapy machines produce neutrons by photonuclear reactions which present a potential radiation hazard to the personnel and patient. A series of measurements of the neutron flux from a 25 MV x‐ray linear accelerator, inside and outside the treatment room, have been performed using a multisphere spectrometer, Nemo dosimeter, and activation detectors. These results are compared with other mixed photon–neutron field measurements for the same machine performed using an argon/propane ionization chamber, silicon diode, track‐etching detectors, and Monte Carlo calculations. It is found that these measurements agree with each other within a factor of two except for silicon diode measurements in the photon beam. Measured neutron spectra at various locations in the treatment room are also compared with the results of Monte Carlo transport calculations.