Dispersive refraction of different light-to-heavy materials at MeV $\gamma$-ray energies

TL;DR

This study investigates how different materials refract gamma rays at energies up to 2 MeV, revealing that high-Z materials could be advantageous for gamma-ray optics development beyond current X-ray technologies.

Contribution

It provides the first combined experimental and theoretical analysis of gamma-ray refraction across a range of materials with varying atomic numbers.

Findings

Good agreement between experiment and theory.

High-Z materials are promising for gamma-ray refractive optics.

Potential for developing gamma-ray lenses using high-Z materials.

Abstract

The dispersive behavior of materials with atomic charge numbers varing from $Z = 4$ (beryllium, Be) to $Z = 82$ (lead, Pb) was investigated experimentally and theoretically at $\gamma$-ray energies up to 2 MeV. The experiment was performed at the double-crystal gamma spectrometer GAMS6 of the ILL in Grenoble. The experimental results were compared with theoretical calculations which account for all major elastic processes involved. Overall, we found a good agreement between theory and experiment. We find that for the development of refractive optics at $\gamma$-ray energies beyond those currently in use high-Z materials become increasingly attractive compared to the beryllium lens-stacks used at X-ray energies.