The development of a 10 micron imaging system.

This thesis presents a description of the design, development and construction of an Infrared photometer for astronomical use. The primary waveband for the intended system is 8 to 14 microns. The photometer is intended to produce images of extended sources, with a maximum resolution of 16 x 64 pixels (8 x 30 mm), equivalent on a 1.5m, fl3 telescope to an angular resolution of ~ 4 x 1 arc minutes. The method of observation is via the use of a linear strip array of discrete semiconductor detectors. The image field is scanned over the array in order to produce a two dimensional map. A focal plane scanning system has been incorporated into the photometer for this very purpose, making the unit almost totally independent of any specific telescope. Much of the research was centered around the fabrication of the detector array, using Copper Doped Germanium as the basic material, although experiments were carried out with Arsenic Doped Silicon and Lead Tin Telluride. The thesis not only discusses the problems involved in handling these materials, but also includes a section upon the housing of the detectors within a Liquid Helium cooled cryostat. The control system for the Photometer is treated in some depth in order that it may represent a working manual to the operation of the equipment, and therefore includes details of most of the electronic systems relevant to the project. Finally, a brief operational test, carried out on the 1.5m IRFC at Tenerife, is analysed and the results presented. The resultant instrument functioned with an image resolution of 12 working detectors x 64 pixels. The approximate NEP for these detectors was 5 x 10-13 Watts, leading to a Specific Detectivity of ~ 1.0 x 1011 cm (Hz)1/2 W-1 on the Tenerife telescope.