Besana, M.I. Hohmann, E. Sapinski, M. Snuverink, J. Werthmüller, D. JACoW Publishing Geneva, Switzerland 2673-5482 978-3-95450-212-7 10.18429/JACoW-CYCLOTRONS2022-WEAO05 English 163-166 proton simulation cyclotron radiation detector Contribution to a conference proceedings 2023 2023-10 https://doi.org/10.18429/JACoW-CYCLOTRONS2022-WEAO05 https://jacow.org/cyclotrons2022/papers/weao05.pdf During an inspection of a new Long Radial Probe, inserted into the Ring cyclotron only a month earlier, an activation hot spot has been identified. The nature of this hot spot has been investigated by performing measurements of the residual activation using shielded Al₂O₃:C dosimeters, 5 mm in diameter, and a portable gamma spectrometer. Monte Carlo simulations of the probe activation with various proton energies have been performed. Results show that most of the activation comes from relatively fast decaying radionuclides and therefore the residual dose drops sufficiently during the shutdown to allow for maintenance and upgrade works. Comparing the abundances of various radionuclides estimated from measured gamma spectra with simulations at various proton energies we conclude that the most probable loss mechanism is scattering of the protons on the upstream collimator.