Use this URL to cite or link to this record in EThOS:
Title: An inductive superconducting transition-edge nano-detector for nano-dosimetry applications
Author: Li, Bo
ORCID:   6284-125--
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Access from Institution:
In this thesis I have demonstrated the feasibility of using Inductive Superconducting Transition-Edge Sensor (ISTED) as an excellent nanodosimeter for nano-dosimetry applications. This thesis can be divided broadly into two parts. In the first part, I begin by addressing how the study of low energetic ionising particles in liquid water using concepts from classical mechanics is a valid approach, despite being inside the quantum-classical boundary regime. Based on the circumstantial validity condition, I showed that the percentage uncertainties in nanodosimetric quantities due to Heisenberg's uncertainty principle for sub- 1 keV electrons in liquid water as calculated by GEANT4-DNA is not significant enough to cause changes to their distributions. Important nanodosimetric quantities studied in details are ionisation cluster-size distribution, second order of moment for cluster-size distribution (M₂) and the cumulative frequency of ionisation cluster-size distribution from cluster-size two (F₂). In the second part of my thesis, I have focussed on the design, optimisation, fabrication, characterisation of the superconducting devices. An ISTED is made from three components: a) a Superconducting Quantum Interference Device (SQUID), b) a superconducting thin-film and c) a top layer of thin-film Carbon absorber. I have measured the magnetic flux noise of a nanoSQUID of loop dimension 350 nm and nano- Josephson junctions of dimensions 65 nm x 65 nm as 3 x 10⁻¹⁴ Φ₀² in the white noise region. It is shown that the measured nanoSQUID is more than capable of sub- 10 eV energy detection.
Supervisor: Nisbet, Andrew ; Cox, David ; Hao, Ling ; Palmans, Hugo Sponsor: Engineering and Physical Sciences Research Council (EPSRC)
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral