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Next: Future work Up: ACIS/HRMA Performance Prediction Previous: Pileup for PSF concentrated

On-orbit performance prediction

The data collected at the XRCF cannot be directly applied to prediction of in-orbit performance because several significant affects influence the ground data which will be different in orbit. The source at XRCF is not located at an infinite distance from the ACIS, the gravitational effects of loading on the HRMA structure cannot be perfectly removed by the HRMA mounting fixture, and the ACIS operating temperature differs slightly from the expected in-orbit values. Thus we must use the data collected at XRCF and the sub-assembly results to refine and validate a model of the HRMA/ACIS response.

The preceeding sections describe the status of the testing and validation of the model. Then, given raytrace models of the HRMA which are appropriate to zero-gravity and infinite source distance, we apply our ACIS models to obtain predictions of the in-orbit performance.

For this preliminary report we have only recently received the ray-trace results for the XRCF tests. We will in future reports obtain the in-orbit ray-traces and produce user-friendly summaries of the expected HRMA/ACIS performance.

Mark Bautz