We have developed a direct X-ray detection system using a charge-coupled device (CCD) to work in a photon counting mode. It can obtain an X-ray spectrum at low X-ray intensity level while it can obtain an X-ray energy flux for each pixel at high X-ray intensity level. Its energy resolution is as good as that of the solid-state detector while its position resolution is as good as that of the micro-channel plate. Using an appropriate X-ray focusing system, we can simultaneously obtain X-ray images at various X-ray energies. Therefore, we can get material distributions in the image with picking-up characteristic X-rays.
A former X-ray non-destructive inspection equipment has been using X-ray that has over 20KeV energy (hard X-ray) and is suitable to take and image of material that's main component is heavy element, but it has a defect that it is impossible to get high contrast as imaging light element material. So it is required to use very low energy X-ray in order to take a high contrast image in that case. An overall excellent detector that is possible to take an image under 20KeV with TV system has not been produced yet. So, we have developed an X-ray non-destructive inspection equipment to aim using more than 4KeV X-ray in order that we can inspect easily light element material in high quality image.
A one inch X-ray vidicon (imaging camera tube) with photoconductive target consisting of CdS/CdTe heterojunction has been developed. The X-ray vidicon having a 1-μm-thick CdS layer and 10.5-μm-thick CdTe layer shows that the X-ray signal current is about 200 nA/cm^2 for 10 R/min, is higher than 45 nA/cm^2 of conventional PdO X-ray vidicon, and the dark current is about 5 nA/cm^2 at 35 V of target voltage at room temperature.
We developed a novel progressive scan CCD featured by the Multiple Frame-Interline-Transfer (M-FIT) structure. The 2/3-inch 520k (948x486) pixels M-FIT CCD has been implemented on the basis of the 2poly-Si conventional manufacturing process , exhibiting the characteristics of wide aspect ratio of 16:9 (switchable to 4:3), dynamic range of 80dB, and sensitivity of 25nA/lx.