| 摘要 |
<p>A controller (CT) irradiates, with laser light, a diffraction-light receiver (28) on which a diffraction ring is recorded by X-rays diffracted by an object to be measured, and measures the diffraction ring. The controller (CT) calculates the laser-light intensity using a radius value of a position irradiated with the laser light, such that the change in the attenuation amount of diffracted X-rays which increases in accordance with an increase in the radius value is corrected, and irradiates the diffraction-light receiver (28) with laser light having the calculated laser-light intensity. Furthermore, the controller (CT) calculates a focus-control value using the radius value, such that the change in the area which receives the diffracted X-rays when the object to be measured is irradiated with the X-rays, and which increases in accordance with an increase in the radius value, is corrected, uses an object lens (30) to control a focus position in accordance with the calculated focus-control value, and controls the diameter of a laser-light spot formed on the diffraction-light receiver (28).</p> |
