Measurement of neutron energy spectra and neutron dose rates from Li-7(p,n)Be-7 reaction induced on thin LiF target

作者：Atanackovic Jovica^*; Matysiak Witold; Dubeau Jacques; Witharana Sampath; Waker Anthony

来源：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2015, 774: 6-16.

DOI：10.1016/j.nima.2014.11.057

• Accelerator neutron metrology
• Accelerator neutron dosimetry
• Accelerator based neutron sources
• Bonner Sphere Spectrometer
• ROSPEC
• Nested Neutron Spedronieem

The measurements of neutron energy spectra and neutron dose rates were performed using the KN Van de Craaff accelerator, located at the McMaster University Accelerator Laboratory (MAL). Protons were accelerated on the thin lithium fluoride (LiF) target and produced mono energetic neutrons which were measured using three different spectrometers: Bonner Sphere Spectrometer (BSS), Nested Neutron Spectrometer (NNS), and Rotational Proton Recoil Spectrometer (ROSPEC). The purpose of this work is (1) measurement and quantification of low energy accelerator neutron fields in terms of neutron fluence and dose, (2) comparison of results obtained by three different instruments, (3) comparison of measurements with Monte Carlo simulations based on theoretical neutron yields from Li-7(p,n)Be-7 nuclear reaction, and (4) comparison of results obtained using different neutron spectral unfolding methods. The nominal thickness of the LiF target used in the experiment was 50 mu g/cm(2), which corresponds to the linear thickness of 0.19 mu m and results in approximately 6 keV energy loss for the proton energies used in the experiment (22, 2.3, 2.4 and 2.5 MeV). For each of the proton energies, neutron fluence per incident proton charge was measured and several dosimetric quantities of interest in radiation protection were derived. In addition, theoretical neutron yield calculations together with the results of Monte Carlo (MCNP) modeling of the neutron spectra are reported. Consistent neutron fluence spectra were obtained with three detectors and good agreement was observed between theoretically calculated and measured neutron fluences and derived dosimetric quantities for investigated proton energies at 2.3, 24 and 2.5 MeV. in the case of 2.2 MeV, some plausibly explainable discrepancies were observed.

• 出版日期2015-2-21