The ROSAT spacecraft is due for launch in June 1990. On board will be an X-Ray Telescope (XRT) and an XUV Wide Field Camera (WFC). The XRT will perform the first ever imaging all sky survey in the 0.1 keV- 2.0 keV wave-band. This will be complemented by the first all sky survey in the 0.062 keV - 0.21 keV wave-band using the WFC. A scientific simulator has been developed to assist the WFC mission in the following areas: 1. Production of representative telemetry to develop and test the ROSAT WFC ground system software. 2. Determination of optimum parameters for several WFC firmware and hardware features. 3. Evaluation of background radiation effects on operational and astrophysical aspects of the WFC mission. The modelling and simulation of the performance aspects of the WFC telescope and its interaction with the predicted environment is described here. The complete model has been implemented as a user orientated software package and can be run to produce scientific telemetry and other simulated output that interface with the ROSAT WFC ground system software. The results of the simulator provide essential foresight into the following: The efficacy of image analysis software. The efficiency of in-orbit WFC low energy (50 keV) electron rejection. Prediction of all sky exposure coverage, the background environment, and minimum source sensitivity.

published_or_final_version / abstract / toc / Physics / Master / Master of Philosophy

published_or_final_version / Physics / Master / Master of Philosophy

No description available.

No description available.

The outcome of several studies into future X-ray astronomy satellite missions has favoured the approach of using grazing incidence optics in conjunction with Charged Coupled Devices (CCD's) as focal plane detectors. This approach allows astrophysical investigation of unprecedented sensitivity by maximising source detectability and by resolving the source spectra. This thesis covers work performed in the development and evaluation of EEV CCD's for use as focal plane X-ray detectors. Due to the nature of the space environment, the interactions of radiation with CCD's also form a major part of this thesis. The subject of X-ray astronomy is introduced and the considerations affecting the operation of CCD's in space are discussed. The construction and operation of the CCD is thoroughly reviewed. The equipment and techniques used to evaluate the performance CCD's to X-rays are presented. A model is developed to simulate the interaction of X-rays with CCD's and this is followed by detailed measurements of X-ray performance. Further improvements to the design of CCDs to optimise their use as X-ray detectors are also discussed. These improvements include increased high and low energy quantum efficiency, larger area, low noise, reduced dark current and increased tolerance to radiation damage. Sources of background signal are investigated which lead to background rejection schemes for different CCD designs. Modelling is also performed to simulate an application of CCD's in space. Measurements of the radiation damage suffered by the CCD's are given and the damage mechanisms which will ultimately lead to device failure in space are discussed. The radiation damage covers irradiation using Co60 and heavy ions, but focuses on the effects of protons of doses below 5 krads. The impact of such a fluence on the scientific performance of an X-ray satellite is evaluated.

vii, 170 leaves : ill. ; 25 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics, 1972

Thesis (Ph.D.) -- University of Adelaide, Dept. of Physics, 1972.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 131-143) Also available in print.

Thesis (M. Phil.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves [76]-81).