Neutron measurements from the interaction of a thick Ta target with protons at different energies

Neutron dosimetry and spectrometry with a Ta target is of concern in an accelerator environment considering its enormous use in a proton accelerator. The Ta target has a unique advantage considering the generation of short half lived radionuclides upon interaction with protons. This advantage extends its use as the beam stopping material at various locations of an accelerator. However, this target has a varied range of reactions to produce neutrons and prompt gammas depending on proton energies. So in the present work, the neutron spectra were generated at various incident proton energies and neutron ambient dose equivalents were estimated close to the target projectile interaction at 90°with respect to the incident beam direction. A comparison of the spectral nature and doses were also done with measurements made by our earlier studies carried out at 0°. The comparison clearly showed that, apart from an increase in the low energy neutron yields at 90°, the overall yield distribution remains similar at both 0°and 90°angles with respect to the incoming beam direction. The ratio of the ambient neutron dose equivalent is found to reduce by a factor of 3–4 at 90°compared to 0°over the entire incident proton energy range. So, the dose equivalent ratio at two angles can be considered as independent of the incident projectile energy.