Reese, Michael (2018)
Intermediate-energy Coulomb excitation with the PreSPEC-AGATA setup.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung

Kurzbeschreibung (Abstract)

This thesis is about the improvement of software tools and methods for analyzing high resolution γ-ray spectroscopy data of intermediate energy Coulomb excitation experiments at the PreSPEC-AGATA setup. In the past, pioneering experiments have been done in the RISING campaign at GSI. The PreSPEC-AGATA setup has been the next step in the evolution of this type of experiments, with better and more complex instrumentation, leading to higher sensitivity and resolution. This work is relevant for for the preparation of the even more demanding future HISPEC setup at the upcoming FAIR facility. HISPEC experiments will study low-lying excited states of nuclei far from stability, in order to test the validity of nuclear structure models in that area of the nuclear chart. More complex instrumentation results in more complex data analysis programs. In order to deal with the complexity involved in developing such software for the upcoming experiments, a more systematic approach to the development process is needed. Within this work, a software framework was developed to facilitate a systematic and clean software design. This might be helpful for upcoming NUSTAR experiments at FAIR, where a large number of independent detector systems have to be integrated into a big setup. The design of the framework is discussed in the second chapter of this thesis. One important reaction mechanism for the HISPEC experiments is Coulomb excitation at energies of around 150 MeV/u. Because of the purely electromagnetic nature of the interaction, Coulomb excitation is described well by theoretical models. In the third chapter of this thesis, a numerical simulation program for relativistic ion-ion collisions was developed that solves the coupled channel equations for electric Coulomb excitation. In the fourth chapter, the relevant detector systems of the PreSPEC setup are presented, and the calibration of them is discussed. A main aspect of the work was the development of improved ways to analyze data from these devices, and, if possible to provide semi-automatic implementations for their calibration. In the last chapter, the total efficiency of the PreSPEC-setup was determined for a typical Coulomb excitation experiment, and the possibility to measure projectile excitation cross-sections relative to a target excitation cross-section is demonstrated.

Frage zum Eintrag

Redaktionelle Details anzeigen