Preview

γ-ray collimators

Is it possible to improve the conventional γ-ray collimator by integrating cones? In this mini project this question is answered on the basis of Monte-Carlo simulations performed with the Geant4 toolkit. It is a Lundium sub-project with the intention to evaluate what collimator that should be used in the construction of a HPGe crystal scanning system in Lund. To project →

Sub-microsecond alpha-particle emitters studied with fast sampling ADCs

Atomic nuclei north-east to the doubly magic nucleus 208Pb (Z=82, N=126) in the nucleidic chart are very short-lived α-decayers. The properties of these nuclei were rather thoroughly studied before the 1980s, however so called pile-ups aggravated the analysis for the nuclei with half-lives on the order of µs. The interplay between modern electronics and a novel algorithm, developed in my master thesis, open up for a deeper study of the short-lived nuclei. This project aims for a continued thorough analysis of the master thesis data for more reliable half-lives, new decay modes and branching ratios, to in the end improve our understanding of the nuclear structure of these short-lived α-decayers. To project →

Geant4 simulation and characterisation of the Lundium chamber and germanium detector system

This is a project which is to be launched soon and constitute one of the main parts of the thesis. A complete new type of high purity germanium detectors, denoted Compex, will be installed to the box of silicon detectors from the old version of the decay station, TASISpec, and the evolved chamber, Lundium, is to be born. The set-up is to be built in Lund and characterised through a close interplay of Geant4 simulations and measurements.   To project →

Pile-up pulse analysis

To obtain a better understanding of radioactive nuclei, one can study their decay properties, such as decay modes, energy of emitted radiation and half-life. However, some nuclei are much more short-lived than others and have been difficult to study with -now outdated- analogue electronic techniques. Recently, modern digitising electronics, denoted fast sampling ADCs, together with tailor-made algorithms have paved the way for the study of fast decaying nuclei. The development of one of such algorithms and the application of it to experimental data were the main tasks of the thesis.   To project →

Gas stopping cell efficiency @ SHIPTRAP

In the SHIPTRAP experiments, at GSI, precise mass measurements of the heaviest nuclei are performed. The SHIPTRAP research group currently holds the world record with direct mass spectrometry on 256Lr. To be able to measure the first superheavy nucleus, it is necessary to improve the efficiency of the entire set-up. The gas stopping cell is essential as it concerns the efficiency. In this report the prospects of changing the buffer gas from helium to argon is evaluated. To project →