APD-based x-ray imaging telescope using Fresnel zone plates for extremely high spatial resolution

Avalanche photodiode arrays for a high-angular resolution X-ray and gamma-ray imaging telescopes

“…Each image was analyzed as the telescope was moved in 0.071 steps off-axis. The fringe pattern was readily noticeable, resulting in an achievable resolution of $30 arcsec [6]. Because of the symmetry of the system, sources located at positive and negative position relative to normal result in identical patterns.…”

“…Following smoothing and subtraction of the dc frequency [6], the Fourier transform can be calculated to depict the true positions of the sources. The distance r would be determined by the known FZP separation.…”

“…RMD has extended FZP shadow masking to an active detector array of APDs [6]. The FZP masks cast a Moireṕ attern formed from the shadows of an X-ray or gammaray source onto either a segmented or position-sensitive nuclear detector.…”