Nondestructive measurement method to detect water/void inside slabs using compact neutron source by backscattered neutrons

Abstract

A nondestructive inspection method which is in type using backscattered neutrons to detect void and water in concrete with RIKEN Accelerator-driven Compact Neutron Source (RANS) is developed. In this method, it is not necessary to be interposed the sample between the radiation source and the detector as in the conventional method using neutron transmission. The position of water and void in the concrete are measured from the intensity change of the backscattered neutrons selected from the incident up to 1 ms. This study reveals that it is possible to observe the two dimensional distribution of water or void inside slabs up to 6 cm below the slab surface.