Fission of 238u investigated using proton-induced knockout collisions in inverse kinematics
- Autores: Antía Graña González
- Directores de la Tesis: José Fernando Benlliure Anaya (dir. tes.), Jose Luis Rodríguez Sánchez (dir. tes.)
- Lectura: En la Universidade de Santiago de Compostela ( España ) en 2024
- Idioma: español
- Tribunal Calificador de la Tesis: Julien Taïeb (presid.), Francesc Yassid Ayyad Limonge (secret.), Carlos Paradela Dobarro (voc.)
- Programa de doctorado: Programa de Doctorado en Física Nuclear y de Partículas por la Universidad de Santiago de Compostela
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
This thesis focuses on the analysis of the fission experiment performed at the GSI facilities (Germany) in March 2021 within the international collaboration framework R3B (Reactions with Relativistic Radioactive beams).
In the research presented in this work, proton-induced knockout reactions are combined for the first time with the study of fission in inverse kinematics. To do so, 238U beams are accelerated to imping on a liquid hydrogen target (LH2) at 540MeV/u. This experimental technique would provide full kinematics measurements by obtaining the excitation energy for the fissioning nuclei and identifying the mass, charge, and TKE of the two fission fragments on an event-by-event basis. Such data can be obtained by combining the SOFIA (Studies Of FIssion with Aladin) experimental setup with a silicon tracker based on AMS-type detectors and the calorimeter CALIFA (CALorimeter for In-Flight detection of gamma rays and high energy charged pArticles) developed by the R3B collaboration. Proton-induced spallation reactions, and in particular, the few nucleon-knockout collisions, are very versatile because they cover a wide range of excitation energies, enabling the study of fission at both low and high excitation energies by selecting specific reaction channels.
Pre- and post-saddle dynamics were investigated. For the study of the pre-saddle dynamics, the partial fission yields and the width of the charge distribution were calculated for different fissioning systems and compared with previous experimental data. Several theoretical de-excitation models such as ABLA, GEMINI, and SMM were benchmarked. For the study of post-saddle dynamics, the evolution of the fission yields with the excitation energy was evaluated. Several suppression functions were tested, and the combination of two exponentials proved to reproduce the data better. The neutron excess and the even-odd effect were studied for different excitation energies, as well as the total kinetic energies.
