Bits and Pieces for the Nuclear Puzzle - Exploring light exotic nuclei with radioactive ion beams
Doktorsavhandling, 2016

Atomic nuclei are a fascinating case of many-body systems governed by quantum behaviour. This fact and the complex nuclear interaction are reasons why there is not yet a complete theory describing all atomic nuclei. Both experimental and theoretical efforts are needed to change this situation. Stable nuclei have been studied extensively, but more exotic nuclear systems are not yet well understood, and it is there where we expect to find improvements to our understanding of the complex nuclear interaction. Beams of light exotic nuclei have become accessible for experiments, and together with recent advances in detection systems, they open up possibilities for studying extreme nuclear systems up to and beyond the driplines, into the continuum. Experiments with light exotic beams deliver important data from extreme nuclear systems, which help to improve the description of atomic nuclei in general. This thesis is focused on light neutron-rich nuclei, and studies them in different ways. Proton-removal cross sections from boron and carbon isotopes are used to test the reaction model ABRABLA07. The agreement is surprisingly good, but the need for a better understanding of the induced excitation energy is demonstrated. Unbound nuclei beyond the dripline are produced via proton-knock-out reactions and studied. The data on the oxygen isotopes agree well with 3N-interaction shell-model calculations. The rare (β p) decay channel is observed in the halo nucleus 11Be. Nuclear reactions also play an important role in astrophysics and the question of how heavy elements are generated in our universe. Coulomb dissociation cross sections can be used to determine astrophysically important (n,γ) rates. Measured cross sections for 20N, 21N and 17C provide improved input for r-process network calculations.

ISOLDE

GSI

FAIR

R3B

Neutron-rich nuclei

Radioactive Beams

PJ
Opponent: Alexandra Gade

Författare

Ronja Thies

Chalmers, Fysik, Subatomär fysik och plasmafysik

Be-11(beta p), a quasi-free neutron decay?

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics,; Vol. 732(2014)p. 305-308

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Systematic investigation of projectile fragmentation using beams of unstable B and C isotopes

Physical Review C - Nuclear Physics,; Vol. 93(2016)

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Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26

Physical Review C - Nuclear Physics,; Vol. 88(2013)

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What are we made of? We and everything we encounter in our everyday lives consists of atoms, formed by electrons surrounding the atomic nucleus. For the world to be what it is, so that humans could evolve, there need to be (sufficiently) stable atomic nuclei. How can nuclei exist? This is a question to which theres is no satisfying answer yet. How protons and neutrons, its constituents, arrange to form a nucleus is not yet completely understood, i.e. there is no theory which can describe all properties of all atomic nuclei at the same time. This is the ultimate goal of nuclear physics research. Those nuclei that we know from our everyday lives are mostly stable and relatively well-understood. Adding or removing more and more neutrons from a stable nucleus creates unstable (exotic) nuclei, until the nucleus cannot hold together anymore and becomes unbound. Nuclei which are far away from stability are so short-lived that they cannot be found on Earth, and thus they have to be created at radioactive ion beam facilities. We study these nuclei, since it is believed that many of the questions and answers leading to a complete theory can be found there. This thesis reports on several experiments with light, neutron-rich nuclei.[...]

Ämneskategorier

Subatomär fysik

Fysik

Fundament

Grundläggande vetenskaper

ISBN

978-91-7597-426-2

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4107

PJ

Opponent: Alexandra Gade