Hussain, Hamzah;
(2023)
Studying the effects of alternative magnetic field configurations on the sensitivity of the SuperNEMO demonstrator to the 0νββ decay of ⁸²Se.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Thesis_Final.pdf - Other Download (11MB) | Preview |
Abstract
SuperNEMO is a neutrinoless double beta decay (0νββ) experiment with an expected half-life sensitivity in excess of 1026 years for the isotope 82Se. This corresponds to an effective Majorana neutrino mass of 40 - 100 meV. The unique tracker-calorimeter technique used in the SuperNEMO experiment provides the ability to reconstruct the full event topology of almost any double beta decaying isotope, producing “smoking gun” evidence for the 0νββ process and potentially allowing the underlying physical mechanism behind neutrinoless double beta decay to be disentangled. Currently the SuperNEMO demonstrator module is being commissioned and is expected to achieve a half-life sensitivity of 6.5 × 1024 years for the 0νββ of 82Se. A key feature of the SuperNEMO design is the magnetic field that can be used to reject backgrounds originating from sources outside of the detector tracking volume. However, the application of a magnetic field reduces the efficiency of detecting the ββ signal. This thesis presents the development and implementation of a comparative analysis of the detector sensitivity to neutrinoless double beta decay, in the presence of different magnetic field configurations. The magnetic coil for the SuperNEMO demonstrator module has been recently installed and is expected to be activated in due course. The performance of the detector, using three alternative magnetic field configurations, has been considered in this work, including; a uniform field with a constant field strength of 25 G, no field with zero magnetic flux and a realistic field which is a representation of the expected magnetic field taking into account the design of the detector. The neutrinoless double beta decay half-life sensitivity for 82Se has been estimated for three alternative magnetic field configurations using an analysis based on event counting in an optimised energy window. The signal (0νββ) detection efficiency and total background contributions from internal, radon and external sources were considered. A maximum half-life sensitivity limit of 1.4 × 1024 years at 90% CL was achieved for the no field scenario with a region of interest between 2.75 and 2.95 MeV. The performance of the no field scenario was only marginally greater than the uniform and realistic fields (1.2 and 1.0 × 1024 years respectively) under the same conditions. Implications of these findings on the SuperNEMO demonstrator physics run plans commencing 2022 are discussed.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Studying the effects of alternative magnetic field configurations on the sensitivity of the SuperNEMO demonstrator to the 0νββ decay of ⁸²Se |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2023. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10180017 |
Archive Staff Only
 |
View Item |
