First Demonstration of X-ray Mirrors Using Focused Ion Beam

We report on novel X-ray mirrors fabricated with a focused ion beam for future astronomical missions. We fabricated a test sample from a silicon wafer by forming six slits whose sidewalls were used as X-ray reflection surfaces. The six slits were designed with a size of 25 x 300 x 170 mu m(3) and with different inclination angles of 0 and +/- 1 degrees. We examined X-ray reflection using three slits with different inclination angles at Al K alpha 1.49 keV. Consequently, we demonstrated X-ray reflection from all the three slits. All the sidewalls have multiangular components with a microroughness of similar to 1 nm rms. similar to 30-45% of the total surface area is effective for X-ray reflection. We confirmed that the inclination angles are consistent with the designed values. (C) 2016 The Japan Society of Applied Physics