Development of an ultra-high precision x-ray optics

We are developing an ultra high precision Soft X-ray telescope. The design of the telescope is a normal incident one for 13.5nm band using Mo/Si multilayers. Two ideas are introduced. One is the optical measurement system in order to monitor the precision of the optics system. The other is the adaptive optics system with a deformable mirror. Using an X ray-optical separation filter, we can always monitor the deformation of the optics by optical light. With this information, we can control the deformable mirror to compensate the system distortion as a closed loop system. We confirmed that the absolute precision of the wave front sensor was less than 3 nm rms. This is also confirmed that the determination of the image center of each micro lens can be similar to1/100 of the pixel size. The precision of the deformable mirror was roughly 5 nm rms. Using the closed loop control the accuracy of the repeatability of the shape of the deformable mirror is less than 2 nm rms. The shape of the primary mirror was an off-axis paraboloide with an effective diameter of 80 mm. This primary mirror was coated by Mo/Si multilayers. The reflectivity of the primary mirror at 13.5nm was ranging from 30 to 50%. The X ray-optical separation filter was made from Zr with a thickness of similar to170 nm. The transmission of the filter for low energy X-ray was measured and was roughly 50% at 13.5nm.