A feasibility study of the use of 25 keV filtered neutron beams for in vivo neutron activation analysis

Abstract

<p>A combination of iron, aluminum and sulphur has been constructed to filter a resonance spectrum beam such that upon transmission, neutrons of 25 keV energy will dominate. This filtered beam, because of the associated lowered dose rate, allows for longer and more frequent irradiations of the spine when checking for decalcifying bone diseases. Analytical expressions for the thermalized flux distributions in the human body arising from neutron beams of various incident energies were developed and shown consistent with experimental work. Successful activations were carried out with phantoms, dry vertebral columns, and wet bone. Conventional methods for measuring neutron dose rate for neutrons in the keV region were shown invalid. The feasibility of setting up an in vivo neutron activation analysis facility at McMaster University in the future, was discussed.</p>