Design of doubly focusing, tunable (5–30 keV), wide bandpass optics made from layered synthetic microstructures

Abstract

Layered Synthetic Microstructures (LSMs) show great promise as focusing, high-throughput, hard X-ray monochromators. Experimental reflectivity vs. energy curves have been obtained on carbon-tungsten and carbon-molybdenum LSMs of up to 260 layers in thickness. Reflectivities for three flat LSMs with different bandppasses were 70% with ΔE E = 5.4%, 66% with ΔE E = 1.4%, and 19% with ΔE E = 0.6% . A new generation of variable bandwidth optics using two successive LSMs is proposed. The first element will be an LSM deposited on a substrate that can be water cooled as it intercepts direct radiation from a storage ring. It can be bent for vertical focusing. The bandpass can be adjusted by choosing interchangeable first elements from an assortment of LSMs with different bandpasses (for example, ΔE E = 0.005, 0.01, 0.02, 0.05, 0.1 ). The second LSM will consist of a multilayered structure with a 10% bandpass built onto a flexible substrate that can be bent for sagittal focusing. The result will be double focusing optics with an adjustable energy bandpass that are tunable from 5 to 30 keV.