X-ray imaging device and X-ray radiographic apparatus

An X-ray radiographic apparatus, comprising:

• an X-ray imaging device;
• a moving section for spatially moving the X-ray imaging device;
• and
• an X-ray irradiation section placed on an opposite side of the X-ray imaging device with respect to a photographing target for irradiating the photographing target with a transmitted X-ray and making the transmitted X-ray enter into the X-ray imaging device,
• wherein the X-ray imaging device comprises:
• an X-ray detection section including (i) an X-ray conversion layer having a first surface into which the X-ray enters and a second surface opposite to the first surface and made of an X-ray converter material for generating electric charges upon an incidence of the X-ray, (ii) a first charge injection blocking layer formed on the first surface of the X-ray conversion layer, and (iii) a second charge injection blocking layer formed on the second surface of the X-ray conversion layer;
• a cold electron source having a plurality of electron emission sections arranged in a matrix form, each of the electronic emission sections being capable of emitting electrons toward the second charge injection blocking layer of the X-ray detection section;
• a light-shielding section for shielding visible light from entering into the X-ray detection section;
• a voltage application section for applying a voltage to the X-ray conversion layer of the X-ray detection section to generate an electric field which induces avalanche multiplication;
• an electron source drive section for driving the plurality of electron emission sections of the cold electron source in sequence so that the electrons are emitted;
• and
• a read section for electronically detecting the electric charges generated by the incidence of the X-ray into the X-ray conversion layer and then neutralized by the electrons emitted from the plurality electron emission sections, and
• wherein the voltage application section generates an average electric field of between 0.1×108V/m and 0.6×108V/m in the X-ray conversion layer of the X-ray detection section.