Nondestructive detection of heavily shielded materials by using nuclear resonance fluorescence with a laser-Compton scattering -ray source

Kikuzawa, Nobuhiro ; Hajima, Ryoichi; Nishimori, Nobuyuki; Minehara, Eisuke; Hayakawa, Takehito; Shizuma, Toshiyuki; Toyokawa, Hiroyuki*; Ogaki, Hideaki*

We perform a proof-of-principle experiment for a nondestructive method for detecting the elemental and isotopic composition of materials concealed by heavy shields such as iron plates with a thickness of several centimeters. This method uses nuclear resonance fluorescence (NRF) triggered by an energy-tunable laser-Compton scattering (LCS) -ray source. One-dimensional mapping of a lead block hidden behind 1.5-cm-thick iron plates is obtained by measuring an NRF -ray of a lead isotope Pb. We observe a 5512-keV -ray from Pb excited by the quasi-monochromatic LCS -rays with energies up to 5.7 MeV. The edge position of the lead block is consistent with the exact position within the uncertainty.