On-Site Neutron Logging for Cultural Heritage Applications Monte Carlo study

Neutron logging is a nuclear technique based on measurements of gamma radiation emitted from soil and rocks under neutron irradiation. The gamma radiation yields information on the materials present in the irradiated volume and, in principle, can be used to sample unexcavated area and spot the presence of buried archeological artifacts. In this paper, we investigate the feasibility of the technique for applications in cultural heritage by using Monte Carlo techniques. A simulation model of a neutron logging system is developed and used to predict the sampling volume and the gamma ray energy distribution emitted by a region of soil containing a buried copper sample. Results show that the sampling volume is approximately 1.6 x 1.5 x 1.7 m3 when a 14 MeV neutron source is simulated. In addition, gamma ray energy spectra obtained with and without the copper sample with a 100% efficient detector are presented. Additional gamma peaks, generated by the interaction of the neutrons with copper, are visible when the sample is introduced. Changes in the spectral lines are a clear indication of the presence of additional chemical elements in soil, and can be used to reveal the presence of materials hidden in soil, as, for instance, archeological artifacts.