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Full-Text Articles in Physical Sciences and Mathematics
An Introduction To The Quasi-Optical Design Of The Hifi Instrument For The Herschel Space Observatory, Gareth S. Curran, J. Anthony Murphy
An Introduction To The Quasi-Optical Design Of The Hifi Instrument For The Herschel Space Observatory, Gareth S. Curran, J. Anthony Murphy
The ITB Journal
This paper is concerned with the quasi-optical design and analysis of the Heterodyne Instrument for the Far Infrared (HIFI) on board the European Space Agency’s Herschel Space Observatory, which is due for launch in 2007. The paper begins with an introduction to astronomy at submillimetre wavelengths followed by the science that will be carried out by HIFI. The optical layout of HIFI is presented and the quasi-optical techniques used in the analysis of band 5 of the instrument are discussed, in particular, issues associated with the design and performance of the integrated lens antenna for this band. A power coupling …
Cosmic Radiation, Anthony Keane
Cosmic Radiation, Anthony Keane
The ITB Journal
The planet Earth orbits the Sun in what is often considered to be empty space but is in fact full of very small charged particles speeding in all directions. The situation can be compared to the Earth having to constantly travel in a light shower of rain and with the atmosphere acting like an umbrella. The 'rain' is made up of charged particles called 'Cosmic Rays'. The name cosmic ray was given long ago to invisible ionising radiation that could mysteriously discharge an electroscope even when the electroscope was heavy insulated. Early scientists quickly established a relationship between the rate …