Development of Achromatic Paraboloidal Mirror Lenses with 100nm Focus

Synchrotron x-ray radiation has become an integral tool relied by scientists across a diverse range of academic and industrial disciplines, ranging from the development of new drugs and environmental or agricultural studies, to cutting-edge research on semiconductor and advanced materials. Recent advances across multiple fields toward nanometer-scale studies has resulted in tremendous demand among the burgeoning synchrotron community for increased access to smaller microbeams down to 100 nanometer or even 10 nanometers. This proposal aims to address the major concerns highlighted at a recent Department of Energy sponsored workshop, in which leaders of the synchrotron community identified manufacturing and technological limitations of current approaches to synchrotron x-ray optics as bottlenecks to advancing research performed at the synchrotron. This Fast Track proposal will develop an innovative approach to developing a single-bounce, axially symmetric and achromatic x-ray mirror lens with paraboloidal inner profiles capable of focusing x-rays down to 100 nm. These paraboloidal mirror lenses will have 2X larger numerical aperture than Kirkpatrick-Baez x-ray mirrors (thereby providing 4X more x-ray flux and flux density), >80% focusing efficiency, and a working distance that can be customized to specified need, which will enable upgrades of older, less used beamlines that may otherwise be retired or the cost-effective building of new, shorter beamlines. Proposed deliverables in Phase I include the development of: an optical shaping system, a measurement (metrology) system to determine the quality of the optic and provide rapid feedback on fabrication parameters, and one paraboloidal mirror lens designed for 10 keV x-rays. This lens will be used to demonstrate a 700 nm focus at 8 keV during Phase I. Deliverables in Phase II will build upon the developmental work of Phase I through planned iterative improvements to the stability and capabilities of the optical shaping system and upgrades to the metrology system for greater precision and accuracy. Ultimate deliverables of Phase II are the fabrication of four paraboloidal mirror lenses capable of achieving 100 nanometers, and with each designed for a different x-ray energy (5, 10, 15, and 20 keV). The paraboloidal mirrors will accelerate and empower the scientific work performed with x-ray microbeam techniques that impact our knowledge and life quality, by providing substantially higher flux over current optics approaches and thus reducing data acquisition times for more efficient use of limited synchrotron beam time. It will furthermore enable cost-effective developments of and upgrades to beamlines, thereby facilitating widespread access of high resolution x-ray microbeam techniques to a broader base of researchers. In addition, the technology and process developed in this fast-track proposal can be leveraged for developing high performance and high resolution laboratory x-ray equipment. Synchrotrons are extremely powerful sources of x-rays that are used by scientists in cutting-edge research in fields spanning from semiconductors to pharmaceuticals and agriculture. This proposal aims to develop innovative x-ray optics for efficient focusing of synchrotron x-rays to address major scientific questions at the nanometer and subcellular scales.