Bracken, Colm
(2015)
Electromagnetic Techniques for Analysis
and Design of Ultra Sensitive Receivers
for Far-Infrared Astronomy.
PhD thesis, National University of Ireland Maynooth.
Abstract
This thesis focuses on EM (electromagnetic) modelling methods for simulating the
behaviour of receivers and detectors for far-IR (far-infrared) astronomy and CMB
(cosmic microwave background) applications, toward an optimum design for SAFARI
(the Spica Far-Infrared Instrument) on the proposed space based telescope
SPICA (Space Infrared Telescope for Cosmology and Astrophysics). The computational
methods required for modelling SAFARI-like receivers are described, and
sophisticated conical waveguide mode matching theory is derived. Generic far-IR
systems are investigated, including analysis of SAFARI-like multi-mode feed horns,
and the absorber coupled superconducting TES (transition edge sensor) bolometers
that are typically used in far-IR receivers. Special attention is given to the integrating
cavity backshorts that serve to increase pixel efficiency, and new designs
for improved cavity geometries, which provide high coupling between the detector
and the incoming signal while reducing cavity losses and crosstalk, are presented.
Where more than one simulation approach is employed for a particular problem, the
agreement between the results served to mutually validate the approaches. Where
necessary, experimental measurements were carried out for verification of the simulations,
and the corresponding results are presented. The results of a measurement
campaign carried out at SRON (Netherlands Institute for Space Research) during
an extended visit during the summer of 2013 are presented, where a SAFARI-like
horn antenna was characterised in terms of its frequency dependent throughput at
THz (terahertz) frequencies. A series of cavity mounted absorber measurements are
also described, where the detector components are appropriately scaled up in size to
suit the frequency range of the in-house VNA (vector network analyser) system at
NUIM (National University of Ireland, Maynooth). The main drivers for the work
presented in this thesis were two Technology Research Programmes, both commissioned
by ESA (European Space Agency).
Item Type: |
Thesis
(PhD)
|
Keywords: |
Electromagnetic Techniques; Analysis;
Design; Ultra Sensitive Receivers;
Far-Infrared Astronomy; |
Academic Unit: |
Faculty of Science and Engineering > Experimental Physics |
Item ID: |
6038 |
Depositing User: |
IR eTheses
|
Date Deposited: |
17 Apr 2015 10:24 |
URI: |
|
Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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