| A large imaging gas scintillation proportional counter (LIGSPC) has been built and calibrated at the Columbia Astrophysics Laboratory (CAL). This instrument combines the good energy resolution of a gas scintillation proportional counter (GSPC) with the good spatial resolution of a multiwire proportional counter (MWPC). We present experimental results obtained with this detector and interpret them in terms of the physical processes underlying its operation.;Placed at the focal plane of a grazing incidence mirror and a coded aperture mask, the LIGSPC forms the basis of a broad band X-ray imaging spectrophotometer (BBXRIS) for the study of cosmic X-ray sources. We discuss the principles involved in the design of an experiment based on the BBXRIS concept and look at two specific examples, preparations for which are now underway.;A coded aperture mask whose pattern is based on a pseudorandom sequence has been tested with the LIGSPC. We discuss the effects that several physical design limitations have on the image deconvolution and compare analytical, simulated, and experimental results. |
