  Ghost tomography using single-pixel detection extends the emerging field of
ghost imaging to three dimensions, with the use of penetrating radiation. In
this work, a series of spatially random x-ray intensity patterns is used to
illuminate a specimen in various tomographic angular orientations with only the
total transmitted intensity being recorded by a single-pixel camera (or bucket
detector). The set of zero-dimensional intensity readings, combined with
knowledge of the corresponding two-dimensional illuminating patterns and
specimen orientations, is sufficient for three-dimensional reconstruction of
the specimen. The experimental demonstration of ghost tomography is presented
here using synchrotron hard x-rays. This result expands the scope of ghost
imaging to encompass volumetric imaging (i.e., tomography), of optically opaque
objects using penetrating radiation. For hard x-rays, ghost tomography has the
potential to decouple image quality from dose rate as well as image resolution
from detector performance.
