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Development of the 200-[u]m photometer for ground-based astronomy.

Walker, Richard J. 2004. Development of the 200-[u]m photometer for ground-based astronomy. PhD Thesis, Cardiff University.

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The thesis presented here describes the design and construction of a 200-um photometer, THUMPER, a seven-element array of stressed Ge:Ga photoconductors. The photometer has been designed to observe at the James Clerk Maxwell Telescope (JCMT) in conjunction with SCUBA, with an angular resolution of 14". A model for the expected atmospheric transmission at high-altitude, ground-based sites is developed. The model is validated through comparison with site-testing measurements of the atmosphere near to the 200-um window. It has been found that THUMPER will be able to undertake useful observations with levels of precipitable water vapour less than around 0.5 mm, occurring under the most favourable of weather conditions. The opportunities for THUMPER provided by the sites at Mauna Kea, Atacama and Antarctica are reviewed. Details concerning the manufacture and testing of stressed Ge:Ga photoconductors are presented. This includes work carried out on prototypes, followed by a description of the detectors used in the THUMPER arrays. The THUMPER detectors were tested individually and found to have values of detective quantum efficiency ranging from 6 to 12%. The basic design parameters for THUMPER are presented along with considerations for the commissioning of our instrument. In addition to plans for the integration of THUMPER at the JCMT, flux calculations have been presented indicating both Mars and Jupiter will provide sufficient fluxes for initial calibration.

Item Type: Thesis (PhD)
Status: Unpublished
Schools: Physics and Astronomy
Subjects: Q Science > QB Astronomy
ISBN: 9781303200991
Funders: PPARC
Date of First Compliant Deposit: 30 March 2016
Last Modified: 10 Oct 2017 15:24

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