New analytical approach for neutron beam-hardening correction

• Energy shift of neutron spectrum transmitted through strong absorbing materials was studied.
• A new approach was proposed for beam-hardening correction in neutron tomography.
• MCNP simulated projection was adjusted for a correct tomographic reconstruction.
• FBP method was used for two-dimensional (2D) image reconstruction.

In neutron imaging, the beam-hardening effect has a significant effect on quantitative and qualitative image interpretation. This study aims to propose a linearization method for beam-hardening correction. The proposed method is based on a new analytical approach establishing the attenuation coefficient as a function of neutron energy. Spectrum energy shift due to beam hardening is studied on the basis of Monte Carlo N-Particle (MCNP) simulated data and the analytical data. Good agreement between MCNP and analytical values has been found. Indeed, the beam-hardening effect is well supported in the proposed method. A correction procedure is developed to correct the errors of beam-hardening effect in neutron transmission, and therefore for projection data correction. The effectiveness of this procedure is determined by its application in correcting reconstructed images.