High-throughput optics for X-ray astronomy (*)(**)

High-throughput X-ray optics are required for future X-ray astronomy missions. These optics are composed of a large number of nested confocal mirrors with very thin thickness in order to reduce the losses due to the obstruction of the mirrors wall and to keep the weight within acceptable values. The replica technique by electroforming the mirrors from mandrels provides a cost-effective solution for the manufacture of these X-ray optical systems. In the paper is reported the application of the electroforming process for the fabrication of the X-ray imaging concentrators for the SAX project and for the JET-X X-ray telescope. Moreover some considerations are given concerning a possible use of more elaborated electroforming processes for manufacturing light-weight large-aperture X-ray optics.