New-Conception-Multilayer Hard X-Ray Telescope For X-Ray Astronomy

Several reflection techniques of hard X-rays (>10 keV) are currently under study. Among these, the reflection from two material multilayer coatings with graded d-spacing appears very promising to focus hard X-rays of energy up to about 80 keV. Taking account of the present technology to fabricate multilayers, Kirkpatrick-Baez configurations appears already feasible. We propose here new techniques to fabricate multilayers that can permit to build a Wolter I hard X-ray concentrator with great advantages in imaging performance and sensitivity. The new techniques are an extension of the replication technology by electroforming that are successfully employed for the SAX and JETX missions. A concentrator configuration based on these techniques is proposed.