Low Z(sub 1)/low Z(sub 2) multilayer x-ray optical thin films.

摘要

The authors have deposited, via magnetron sputter deposition, multilayer structures comprised of alternating layers of low atomic number materials such as: (1) carbon and boron carbide, (2) silicon and boron carbide, (3) silicon and carbon and (4) aluminum and boron carbide. Layer periods for these materials combinations range from 63.5 to 75(angstrom). These low atomic number multilayers exhibit significant first order Bragg diffraction of Cu k-alpha radiation. Calculations of the reflectivity performance for multilayers of this composition have been made using a computer code based on the Modified Darwin-Prinz theory. Experimental measurements and code predictions are in close agreement. Multilayers of this type may find application in devices requiring ultra-low dispersion focusing x-ray optics, such as long focal length focussed beam lines, x-ray microscopes and x-ray telescopes. Diagnostics for plasma characterization in fusion experiments that are free from Ledge absorption, high transmittance/high resolution beam splitting x-ray optics, and output couplers soft x-ray laser cavities are other possible applications for low-Z(sub 1)/low-Z(sub 2) multilayers.