Reaction yields and angular distributions of prompt y-rays for range verification in proton therapy using 18O

Current Prompt-Gamma systems suffer from limitations due to the high-energy character of the PGs emitted by natural tissues, comprised between 2 and 7 MeV, which present a very low detection efficiency. In this work, we introduce a novel approach to mitigate these efficiency problems by employing a contrast agent to produce prompt-gamma radiation below 2 MeV. We conducted experiments to measure the production yields, y-ray angular distributions, and cross sections of prompt-gamma emissions in the 18O(p,Xy) reaction below 10 MeV. We have identified and studied 5 PG emissions, three of them with energies close to 1 MeV, and two others at energies close to 2.0 and 5.3 MeV. The results presented in this publication demonstrate that the emission cross sections obtained from the investigation of PGs from 18O(p,Xy) are well-suited to mitigate the existing limitations of these techniques. This lays the groundwork for future research and the advancement of contrast-enhanced PGs techniques.