Penumbral imaging of laser-imploded targets and its blind reconstruction

We describe a use of the penumbral imaging technique for hard X-ray imaging of laser-imploded targets. The technique uses the fact that spatial information can be recovered from the shadow or penumbra that an unknown source casts through a simple large circular aperture. The imaging system consists of a large circular aperture (penumbral aperture), filters, and a sensitive X-ray CCD camera as a detector. The X-ray images with photon energies of 5 keV and 10 keV to 30 keV were obtained. We also propose a new reconstruction method based on power cepstrum of the penumbral image, which does not require exact information about the aperture function.