Evaluation of a virtual phase charged-coupled device as an imaging x-ray spectrometer

The x-ray response of an 800×800 Texas Instruments virtual phase charge-coupled device (CCD) has been measured in the range 1–8 keV. In the single-photon counting mode, we find excellent energy resolution (∼250 eV FWHM) for single-pixel Fe55 x-ray events at a spatial resolution of 15 μm. The detector quantum efficiency for all events is 65% at 2.3 keV (S K line) and ∼34% at 5.9 keV (Mn K line from Fe55). The CCD response is linear in energy to a few percent over the 1–8 keV energy range. These results demonstrate that virtual phase CCDs are superior imaging x-ray spectrometers with applications for x-ray astronomy and laboratory plasma research.