PURPOSE: To improve the accuracy of a system by using a maximum intensity point on the luminous intensity distribution of a fluorescent material on target surface upon exposure to X-ray irradiation, and setting an optical system by use of a line perpendicular to the target surface across the focal point position as an optical axis.
CONSTITUTION: The target surface of an X-ray source 1 is covered with a fluorescent material. A laser beam emitted from a laser 2 is made to pass a half mirror 3 and the half of the beam is thereby irradiated to the target surface of the source 1. In this case, when a mirror 6 is inserted, the laser beam is reflected and returns to a laser irradiation port via the half mirror 3. This laser spot, when superposed on the irradiation port, means that the laser beam is perpendicularly irradiated to the target surface. When the spot is not superposed on the port, a mirror 5 is adjusted for an incident angle and a laser beam perpendicular to the target surface is obtained. Then, the mirror 6 is detached and the target surface is observed with a camera 7. In this case, the fluorescent material, when exposed to an X-ray, is luminous and a maximum intensity point on a luminous distribution becomes an X-ray focal point position on the target surface. Thereafter, an optical table is moved for superposing the X-ray focal point position on the laser spot. Then, the mirror 6 is again inserted and a laser beam emitted from the X-ray focal point position and perpendicular to the target surface is obtained. This beam is used as an optical axis to set an optical system.
IWATA SATOSHI
NISHIYAMA YOJI
