Foil Mirrors and Multilayer Developments at Goddard

This paper summarizes progress at Goddard toward incorporating refinements into the foil mirror technology that extend its utilization in astronomical research well into the future. The Japan/US collaborative mission ASCA has demonstrated both the strengths of first generation foil mirrors but also the areas where improvements will be needed. A radical change in the way we smooth the foil surface has already been implemented and represents an important first step that has considerably improved the imaging capability of our second generation mirrors. Additional breakthroughs are still needed, however, if foil mirrors are to play a major role in the Next Generation X ray Observatory era. Foil mirrors offer, additionally, a number of attractive attributes as regards the use of multilayers to extend imaging spectroscopy to tens of keV. Preliminary results of multilayers deposited on our new foil reflectors are very encouraging.