Patent ID: 8000443

Claim:
A high precision posture control method of an X-ray mirror for collecting X-rays, from hard X-rays to soft X-rays, at a high spatial resolution with a light collection spot of 100 nm or less, said method comprising steps of: providing a longitudinal light collection mirror and a lateral light collection mirror, which include light collection surface zones formed of ellipsoidal reflective surfaces with focal points at a light source and a light collection surface; said mirrors being oriented orthogonal to each other in a K-B mirror arrangement; providing a pair of planar reflective surfaces constituting a Fresnel mirror in the vicinities of an incident-side end and an outgoing-side end of the light collection surface zone in each of the light collection mirrors; separately monitoring interference fringes resulting from the Fresnel mirrors in the light collection mirrors at positions which are not influenced by beams collected at the light collection surface zones; electrically detecting changes in the interference fringes; and using detection signals as feedback signals for posture control of the light collection mirrors.