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A: Modeling of High Purity Germanium (HPGe) detector on a wide energy range is important in gamma-ray spectroscopy. The precisely modeled detector can be used for protoninduced prompt gamma-ray spectroscopy. In this work, we used both the gamma-rays of calibration sources and prompt gamma-rays emitted in proton capture reactions to model a coaxial p-type HPGe detector using Geant4 Monte Carlo simulation for the gamma-ray energy range of 59-10764 keV. The calibration sources were 137 Cs, 241 Am, 60 Co, 152 Eu, and 133 Ba, while the prompt gamma-rays were due to the gamma-ray cascades following the 27 Al(p,𝛾) 28 Si reaction capture at the resonant energies of 992, 1317 and 2483 keV, as well as the 23 Na(p,𝛾) 24 Mg reaction capture at the resonant energies of 1417 and 1395 keV. According to the results obtained, the presented simulated and experimental spectra show a good agreement. In addition, the mean and maximum relative deviations between experimental and simulated efficiencies corresponding to 27 major peaks are smaller than 5% and 15%, respectively. K: Gamma detectors (scintillators, CZT, HPGe, HgI etc); Simulation methods and programs; Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc); Accelerator Applications

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Purpose: Online determination of the elemental composition of tissues near the Bragg peak is a challenge in proton therapy related studies. In the present work, an analysis method based on the whole spectral information is presented for the quantitative determination of the elemental composition (weight %) of an irradiated target from its emitted Prompt Gamma (PG) spectrum. Materials and Methods: To address this issue, four test phantoms with different weights (%) of 12C, 16O, 20Ca, and 14N elements were considered. The simulated PG spectra were recorded using 3 × 3 inch NaI detectors. A library consisting of the spectra of single-element phantoms as well as the spectra of test-irradiated phantoms was produced for 30, 70, and 150 MeV incident protons using the Geant4 Monte Carlo toolkit. The elemental analysis was performed using the information of the whole spectrum by applying two methods, including the well-known Genetic Algorithm (GA) and Multiple Linear Regression (MLR). Results: The results show that the proposed method estimates the oxygen concentration accurately. Furthermore, the estimated weights of other elements, with both methods, agree well with nominal values in each test phantom, for the considered energies. Conclusion: The proposed quantitative elemental analysis of proton-bombarded phantoms using their induced PG spectrum is expected to be beneficial in treatment planning and treatment verification studies.