Simulations of Doppler Effects in Nuclear Reactions for AGATA Commissioning Experiments

TL;DR

This thesis simulates nuclear reactions to identify optimal conditions for AGATA gamma-ray experiments, focusing on maximizing Doppler effects while minimizing energy and angular spread contributions.

Contribution

It evaluates various reactions and simulations to determine the most suitable nuclear reaction for AGATA commissioning, specifically identifying d(V-51,n)Cr-52 as optimal.

Findings

d(V-51,n)Cr-52 reaction produces larger Doppler effects.

Target effects influence gamma-ray Doppler broadening.

Simulation results support using d(V-51,n)Cr-52 for experiments.

Abstract

The purpose of this master thesis is to simulate suitable nuclear reactions for a commissioning experiment, to be performed with the AGATA gamma-ray tracking spectrometer. The main aim of the work is to find a reaction, which gives large Doppler effects of the emitted gamma rays, with as small contribution as possible due to the energy and angular spread of the nuclei emitting the gamma rays. Inverse kinematics heavy-ion (HI) fusion reactions of the type (HI,gamma), (HI, n) on proton and deuteron targets have been studied. Target effects were investigated using the program TRIM in order to determine the impact on the Doppler effects caused by energy and angular straggling in the target material. The cross sections of a large number of reactions of protons and deuterons on nuclei with mass numbers in the range A=20-100 have been evaluated using the TALYS reaction code. The fusion-evaporation reactions, d(V-51,n)Cr-52 and d(Cl-37,n)Ar-38 were simulated in detail using the Monte Carlo code evapOR. The interactions in AGATA of the gamma rays emitted in these reactions were simulated using Geant4. The energy resolution of the gamma rays after gamma-ray tracking and Doppler correction were determined as a function of the interaction position resolution of the germanium detectors. The conclusion of this work is that of the two reactions d(V-51,n)Cr-52 is more suitable for an AGATA commissioning experiment.