Replicated Nickel Optics for the Hard-X-Ray Region

Replicated nickel optics has been used extensively in x-ray astronomy, most notably for the XMM/Newton mission. The combination of relative ease of fabrication and the inherent stability of full-shell optics, make them an attractive approach for medium-resolution, high-throughput applications. MSFC has been developing these optics for use in the hard-x-ray region. Efforts at improving their angular resolution, particularly for the very-thin-wall shells required to meet the weight budgets of future missions, are described together with the prospects for future significant improvements.