Author(s): Farinha, Ricardo de Araújo
Date: 2016
Persistent ID: http://hdl.handle.net/10362/20675
Origin: Repositório Institucional da UNL
Subject(s): GUSTO; THz; HEB; Optic Design; Lens Design; PILRAP; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais
The radiation at terahertz (THz) frequency range (1 THz = 300 μm in wavelength) provides us a powerful window into cosmic evolution, from the birth and explosion of stars to the evolution of galaxies and the universe itself. The THz is a largely unexplored region in the electro-magnetic spectrum, partly owing to technological constraints and partly due to atmospheric absorption on the Earth. Consequently, THz astronomy observations are best performed from space-based or balloon-borne telescopes, like the proposed NASA balloon GUSTO mission. The observations will be complementary to other space missions like Hershel’s HIFI instrument. In this work, a model of GUSTO’s optical system was proposed and analysed in order to improve its efficiency in detecting three of the most important terahertz lines, [NII], [CII] and [OI], with multi-pixel heterodyne cameras. Moreover, simulations were performed with PILRAP, a antenna simulation software, to study the parameters that affect the optical f# number and radiation pattern of a 5 mm diameter lens system, and to explain the heterodyne sensitivity differences between a 10 mm lens and 3.1 mm lenses. Outcome of my thesis work concludes the feasibility to use smaller lens for GUSTO’s heterodyne arrays.
