Caracterización de la Reacción de la captura neutrónica por gadolinio

Abstract

The nuclear reaction of neutron capture by the isotope 157-Gadolinium (GdNC, for its English acronym) has garnered increasing interest in recent years due to its applications both on an industrial level in the development of neutron detectors and on a medical level as therapy for tumor treatment. Its use in medical applications is presented as an alternative to conventional treatments such as radiotherapy and chemotherapy, given its property of minimizing damage through irradiation to healthy tissues. This property is a consequence of the high linear energy transfer (LET, for its English acronym) exhibited by some particles in the final state of the associated nuclear reaction, limiting their range to the cellular diameter. The final state of GdNC involves complex processes at both the nuclear level (emission of gammas and internal conversion electrons) and the atomic level (emission of X-rays and Auger electrons) that need to be studied both experimentally and through simulation to advance the understanding of the reaction. Although there are some published works on the GdNC reaction, there is no consensus among them regarding the kinetic energy and the average number of particles produced per event (yield). Moreover, these works often neglect the analysis of other kinematic and dosimetric quantities that could contribute to improving the understanding of the nuclear reaction's characteristics. The main objective of this research work is to characterize the particles in the final state of the neutron capture reaction by the isotope 157-Gadolinium by determining physical quantities such as the distribution of kinetic energy, momentum distribution, angular distribution, deposited energy, and linear energy transfer (LET). To achieve this, a simulation based on the Monte Carlo method using Geant4 will be carried out. In this simulation, an enriched target of 157-Gadolinium surrounded by an aqueous medium will be irradiated with a neutron beam having an epithermal and thermal energy range.