Physiol Meas

This study was conducted to investigate the methodology and feasibility of developing a transportable neutron activation analysis (NAA) system to quantify manganese (Mn) in bone using a portable deuterium-deuterium (DD) neutron generator as the neutron source. Since a DD neutron generator was not available in our laboratory, a deuterium-tritium (DT) neutron generator was used to obtain experimental data and validate the results from Monte Carlo (MC) simulations. After validation, MC simulations using a DD generator as the neutron source were then conducted. Different types of moderators and reflectors were simulated, and the optimal thicknesses for the moderator and reflector were determined. To estimate the detection limit (DL) of the system, and to observe the interference of the magnesium (Mg) \uce\ub3 line at 844\uc2\ua0keV to the Mn \uce\ub3 line at 847\uc2\ua0keV, three hand phantoms with Mn concentrations of 30 parts per million (ppm), 150\uc2\ua0ppm, and 500\uc2\ua0ppm were made and irradiated by the DT generator system. The Mn signals in these phantoms were then measured using a 50% high-efficiency high-purity germanium (HPGe) detector. The DL was calculated to be about 4.4\uc2\ua0ppm for the chosen irradiation, decay, and measurement time. This was calculated to be equivalent to a DL of about 3.3\uc2\ua0ppm for the DD generator system. To achieve this DL with one 50% high-efficiency HPGe detector, the dose to the hand was simulated to be about 37\uc2\ua0mSv, with the total body equivalent dose being about 23\uc2\ub5Sv. In conclusion, it is feasible to develop a transportable NAA system to quantify Mn in bone in vivo with an acceptable radiation exposure to the subject.1R21OH010044/OH/NIOSH CDC HHS/United StatesR01 ES008146/ES/NIEHS NIH HHS/United StatesT42/OH008432-06/OH/NIOSH CDC HHS/United States2014-09-04T00:00:00Z24165395PMC415406