title: High-precision Penning-trap Measurement of the Helium-3 Atomic Mass
creator: Bezrodnova, Olesia
subject: ddc-530
subject: 530 Physics
description: This work presents a high-precision atomic mass measurement of helium-3. The measurement was performed using the Penning-trap mass spectrometer Liontrap, where the cyclotron frequency of the helium ion was measured relative to that of a carbon ion, which serves as a standard in atomic mass units. With a relative uncertainty of 1.2 × 10−11, this result represents the most precise mass measurement of helium-3 in atomic mass units to date. It contributes to resolving the “Light Ion Mass Puzzle” - inconsistencies in the measured masses of light nuclei, namely the proton, deuteron, and helium-3, reported by different Penning-trap mass spectrometers in the past. By demonstrating consistency between the results from Liontrap and those from the group at Florida State University, while simultaneously highlighting a discrepancy with the results from the University of Washington (UW), this work suggests that the earlier Penning-trap measurements by the UW group may have underestimated the uncertainty in their results. Consequently, confidence in Penning-trap measurements  of light ion masses - fundamental constants used to test the validity of the Standard Model - is restored.    During the course of this work, the experimental setup was upgraded to allow for the production of helium-3 ions and an improved detection system. Additionally, a new analysis approach was introduced, which effectively suppresses the dominant systematic effect observed in previous Liontrap measurements, the lineshape effect, by a factor of more than 100. Furthermore, a phase-sensitive method for measuring  the axial frequency has been developed, showing promising potential for improving the statistical precision achievable in Penning-trap experiments in general.    The measurement presented in this thesis concludes a series of studies on light ions conducted at Liontrap, and the experimental setup is now being repurposed  for lepton symmetry tests at MPIK.
date: 2025
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserver/36946/1/Dissertation_Bezrodnova.pdf
identifier: DOI:10.11588/heidok.00036946
identifier: urn:nbn:de:bsz:16-heidok-369468
identifier:   Bezrodnova, Olesia  (2025) High-precision Penning-trap Measurement of the Helium-3 Atomic Mass.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/36946/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng