Fluorescent screen, x-ray detector, and x-ray inspection apparatus

1. A fluorescent screen configured to convert an X-ray into visible light, comprising

a gadolinium oxysulfide phosphor activated with praseodymium and cerium,

wherein the phosphor contains praseodymium having a concentration of 0.01 mass % or more and 0.3 mass % or less and cerium having a concentration of 5 ppm or more and 30 ppm or less,

wherein an average particle diameter of the phosphor is 10 μm or more and 20 μm or less, and

wherein a weight per unit area of the phosphor is 300 mg/cm 2 or more and 380 mg/cm 2 or less.

2. The screen according to claim 1 , wherein the concentration of the praseodymium is 0.03 mass % or more and 0.2 mass % or less.

3. The screen according to claim 1 , wherein the concentration of the cerium is 10 ppm or more and 25 ppm or less.

4. The screen according to claim 1 , wherein the weight is 300 mg/cm 2 or more and 350 mg/cm 2 or less.

5. The screen according to claim 1 , wherein the average particle diameter is 13 μm or more and 18 μm or less.

6. The screen according to claim 1 , wherein a Wadell's sphericity of the phosphor is 0.8 or more and 0.96 or less.

7. An X-ray detector configured to detect a transmitted X-ray from a target, comprising the screen according to claim 1 .

8. The detector according to claim 7 , further comprising

a photodiode configured to convert the visible light into an electrical signal.

9. An X-ray inspection apparatus, comprising:

an X-ray irradiator configured to irradiate an X-ray to a target;

an X-ray detector configured to detect a transmitted X-ray through the target; and

a display configured to display an image of the inside of the target in accordance with an intensity of the transmitted X-ray detected by the X-ray detector,

wherein the detector includes the detector according to claim 7 .