Pulsed neutron imaging using resonance transmission spectroscopy

We are developing the energy-selective neutron radiography and tomography technique by using the pulsed neutron source and the time-of-flight (TOF) spectroscopy. Neutron resonance absorption spectroscopy with computer tomography, N-RAS/CT, can non-destructively give the tomographic image indicating material information such as nuclide, density and temperature inside the object. The primary N-RAS/CT was performed by detecting prompt γ-rays emitted from nuclei absorbing neutrons as a function of neutron TOF. In this case, position dependent data need to be obtained by scanning the object with a moving slit. On the other hand, in this paper, we propose a new N-RAS/CT method using neutron transmission spectroscopy combined with 2-dimensional position sensitive neutron detector (2d-PSND), which is applicable to TOF measurement. The greatest feature of this method is shorter measurement time than the previous one because 2d-PSND can obtain spatial information at once. For this reason, we carried out the new N-RAS/CT experiment to examine its feasibility at the pulsed neutron facility based on the small accelerator.