title: Penning-Trap Mass Spectrometry of Radioactive, Highly Charged Ions:  Measurements of neutron-rich Rb and Sr nuclides for nuclear astrophysics and the development of a novel Penning trap for cooling highly charged ions
creator: Simon, Vanessa Véronique
subject: ddc-500
subject: 500 Natural sciences and mathematics
subject: ddc-530
subject: 530 Physics
description: High-precision atomic mass measurements are vital for the description of nuclear structure, investigations of nuclear astrophysical processes, and tests of fundamental symmetries. The neutron-rich A ≈ 100 region presents challenges for modeling the astrophysical r-process because of sudden nuclear shape transitions. This thesis reports on high-precision masses of short-lived neutron-rich 94,97,98Rb and 94,97-99Sr isotopes using the TITAN Penning-trap mass spectrometer at TRIUMF. The isotopes were charge-bred to q = 15+; uncertainties of less than 4 keV were achieved. Results deviate by up to 11σ compared to earlier measurements and extend the region of nuclear deformation observed in the A ≈ 100 region. A parameterized r-process model network calculation shows that mass uncertainties for the elemental abundances in this region are now negligible.  Although beneficial for the measurement precision, the charge breeding process leads to an increased energy spread of the ions on the order of tens of eV/q. To eliminate this drawback, a Cooler Penning Trap (CPET) has been developed as part of this thesis. The novel multi-electrode trap structure of CPET forms nested potentials to cool HCI sympathetically using either electrons or protons to increase the overall efficiency and precision of the mass measurement. The status of the off-line setup and initial commissioning experiments are presented.
date: 2012-11-13
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/13987/1/Dissertation_VanessaSimon.pdf
identifier: DOI:10.11588/heidok.00013987
identifier: urn:nbn:de:bsz:16-heidok-139875
identifier:   Simon, Vanessa Véronique  (2012) Penning-Trap Mass Spectrometry of Radioactive, Highly Charged Ions: Measurements of neutron-rich Rb and Sr nuclides for nuclear astrophysics and the development of a novel Penning trap for cooling highly charged ions.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/13987/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng