Monochromatic X-ray source based on scattering from a magnetic nanoundulator

TL;DR

This paper introduces a compact, passive X-ray and ultraviolet light source using magnetic nanogratings to generate tunable, monochromatic radiation from low-energy electrons, potentially revolutionizing tabletop X-ray generation.

Contribution

It presents a novel nanostructure-based design for a lightweight, tunable X-ray source that eliminates the need for large-scale accelerators or lasers.

Findings

High directional, tunable, monochromatic radiation achievable

Effective for electron energies from 1 keV to 5 MeV

Reduces size, cost, and complexity of X-ray sources

Abstract

We present a novel design for an ultra-compact, passive light source capable of generating ultraviolet and X-ray radiation, based on the interaction of free electrons with the magnetic near-field of a ferromagnet. Our design is motivated by recent advances in the fabrication of nanostructures, which allow the confinement of large magnetic fields at the surface of ferromagnetic nanogratings. Using ab initio simulations and a complementary analytical theory, we show that highly directional, tunable, monochromatic radiation at high frequencies could be produced from relatively low-energy electrons within a tabletop design. The output frequency is tunable in the extreme ultraviolet to hard X-ray range via electron kinetic energies from 1 keV-5 MeV and nanograting periods from 1 {\mu}m-5 nm. Our design reduces the scale, cost, and complexity of current free-electron-driven light schemes, bypassing the need for lengthy acceleration stages in conventional synchrotrons and free-electron lasers and driving lasers in other compact designs. Our design could help realize the next generation of tabletop or on-chip X-ray sources.