Development of a planar magnetic field source for the Geonium Chip Penning Trap

Lacy, John Henry (2019) Development of a planar magnetic field source for the Geonium Chip Penning Trap. Doctoral thesis (PhD), University of Sussex.

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This thesis presents the theoretical foundation and design of a planar magnetic field source for the Geonium Chip Penning trap. Conventional Penning traps are limited in their scalability by the size of their magnetic field sources, which often take the shape of large and expensive superconducting solenoids. For many practical applications, such as portable mass spectrometry and quantum radar, these conventional Penning trap systems would be unsuitable, due to their large size and need for very high currents (of the order of a few hundred amperes). The Geonium Chip Penning trap aims to overcome this problem by proposing a novel planar magnetic field source comprising several superconducting coils confined to a plane. The electrode surfaces of the trap sit less than a millimetre above the magnetic field source such that the trapping magnetic field is oriented parallel to the electrode surfaces.

In this thesis, I explore many of the fundamental design issues concerned with developing such a planar magnetic field source. In particular, I devise an entirely new scheme of remotely magnetising a plurality of closed superconducting loops to carry currents in persistent mode, and show how persistent supercurrents of hundreds of amperes can be remotely induced with input currents of the order of a few (one to two) amperes. I introduce, and experimentally verify, a theoretical framework that allows for a high degree of control over the magnetic field distribution. From this framework, I present an optimised design of a planar persistent current-mode magnetic field source theoretically capable of achieving a 0.1 T field homogeneous up to fourth order in the Taylor expansion about the trapping position. This magnetic field source is due to be constructed and tested in the coming months.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QC Physics > QC0501 Electricity and magnetism > QC0750 Magnetism
Depositing User: Library Cataloguing
Date Deposited: 12 Jul 2019 09:10
Last Modified: 20 Aug 2020 19:09

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