Open AccessThe neutron dose equivalent around high energy medical electron linear accelerators
Author(s) -
Marina Poje,
Ana Ivković,
Slaven Jurković,
Gordana Žauhar,
Branko Vuković,
Vanja Radolić,
Igor Miklavčić,
Zoran Kaliman,
Josip Planinić,
Hrvoje Brkić,
Dario Faj
Publication year - 2014
Publication title -
nuclear technology and radiation protection
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.31
H-Index - 16
eISSN - 1452-8185
pISSN - 1451-3994
DOI - 10.2298/ntrp1403207p
Subject(s) - neutron , equivalent dose , collimator , linear particle accelerator , bonner sphere , radiator (engine cooling) , dosimetry , electromagnetic shielding , neutron detection , physics , nuclear physics , neutron radiation , neutron temperature , nuclear engineering , nuclear medicine , optics , neutron cross section , beam (structure) , medicine , engineering , quantum mechanics
The measurement of neutron dose equivalent was made in four dual energy linear accelerator rooms. Two of the rooms were reconstructed after decommissioning of 60Co units, so the main limitation was the space. The measurements were performed by a nuclear track etched detectors LR-115 associated with the converter (radiator) that consist of 10B and with the active neutron detector Thermo BIOREM FHT 742. The detectors were set at several locations to evaluate the neutron ambient dose equivalent and/or neutron dose rate to which medical personnel could be exposed. Also, the neutron dose dependence on collimator aperture was analyzed. The obtained neutron dose rates outside the accelerator rooms were several times smaller than the neutron dose rates inside the accelerator rooms. Nevertheless, the measured neutron dose equivalent was not negligible from the aspect of the personal dosimetry with almost 2 mSv a year per person in the areas occupied by staff (conservative estimation). In rooms with 15 MV accelerators, the neutron exposure to the personnel was significantly lower than in the rooms having 18 MV accelerators installed. It was even more pronounced in the room reconstructed after the 60Co decommissioning. This study confirms that shielding from the neutron radiation should be considered when building vaults for high energy linear accelerators, especially when the space constraints exist