Expedition Flerovium

A short popular science story takes you through the highlight of this PhD thesis. In a spectroscopy experiment aiming to study atomic nuclei of element 114, flerovium, new insights were gained into the Island of Stability. This island is a region on the Chart of Nuclides where the possible existence of long-lived superheavy elements has tantalized nuclear physicists ever since the first predictions in the 1960s. To project →

Spectroscopy of Fl-decay chains

In nuclear physics research one of the biggest quests is to find the heaviest element that can exist in nature. The isotopes of these so called superheavy elements are unstable and live for just fractions of seconds or a few seconds before decaying. However, theoretical calculations predict that specific combinations of neutrons and protons may show a substantial increase in stability, i.e. that some superheavy nuclei have lifetimes of hours or years. These extra stable superheavy nuclei form the so called ‘Island of Stability’. With granted new experimental beam time at the accelerator facility GSI, Darmstadt, Germany, and an improved set-up, we now aim to study isotopes of element 114 and bring the research closer to the stability island. To project →

Construction of the Lundium chamber

Probing nuclear structural properties of superheavy nuclei requires a detector set-up with excellent detection efficiency.  Up till now, α-photon coincidence spectroscopy on superheavy nuclei has been achieved with our decay station TASISpec. However, TASISpec is now being upgraded to Lundium. To project →

3D-characterisation of HPGe detectors

The importance of the spectroscopic performance of HPGe detectors in the low-statistics superheavy experiments, cannot be stressed enough. In order to confidently discover new physics and propose new nuclear structure properties it is of utmost importance to know the characteristics of the detectors, especially if it is a new type of detector. In this regard it is hence essential to characterise the Compex set-up in detail. The characterisation can be achieved with a scanning system which is currently under construction in the lab 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 chart of nuclides 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 →

Statistical analysis of decay chains

This is a rather small ongoing project where the purpose is to show transparency when it comes to the statistical analyses that have been performed by the Lund Nuclear Structure Group of the decay chains of superheavy elements.    To project →

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 →

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 →