Imaging neutron capture cross sections: i-TED proof-of-concept and future prospects based on Machine-Learning techniques

i-TED is an innovative detection system which exploits Compton imaging techniques to achieve a superior signal-to-background ratio in (n, gamma) cross-section measurements using time-of-flight technique. This work presents the first experimental validation of the i-TED apparatus for high-resolution time-of-flight experiments and demonstrates for the first time the concept proposed for background rejection. To this aim, the Au-197(n, gamma) and Fe-56(n, gamma) reactions were studied at CERN n_TOF using an i-TED demonstrator based on three position-sensitive detectors. Two C6D6 detectors were also used to benchmark the performance of i-TED. The i-TED prototype built for this study shows a factor of similar to 3 higher detection sensitivity than state-of-the-art C6D6 detectors in the 10 keV neutron-energy region of astrophysical interest. This paper explores also the perspectives of further enhancement in performance attainable with the final i-TED array consisting of twenty position-sensitive detectors and newanalysis methodologies based on Machine-Learning techniques.

Automated summary

This study successfully validated the feasibility of i-TED for high-resolution time-of-flight experiments and demonstrated the concept of background rejection for the first time. Experimental results showed that i-TED has a detection sensitivity approximately 3 times higher than state-of-the-art detectors in the neutron energy region of astrophysical interest. The study also explored the potential for further performance enhancement with a final i-TED array consisting of twenty position-sensitive detectors and new analysis methodologies based on Machine-Learning techniques.