Stroboscopic detection of nuclear resonance in an arbitrary scattering channel

TL;DR

This paper develops a general theory for heterodyne/stroboscopic detection of nuclear resonance scattering across any scattering channel, including complex line shapes due to interference effects, and validates it with experimental data.

Contribution

It introduces a comprehensive theoretical framework for stroboscopic nuclear resonance detection applicable to all scattering channels, extending beyond the forward channel.

Findings

Complex resonance line shapes observed in non-forward channels due to interference.

The theory accurately fits experimental grazing incidence reflection data.

Electronic scattering causes energy-independent intensity reduction in the forward channel.

Abstract

The theory of heterodyne/stroboscopic detection of nuclear resonance scattering is developed, starting from the total scattering matrix as a product of the matrix of the reference sample and the sample under study. This general approach holds for any dynamical scattering channel. The forward channel, which is discussed in detail in the literature, reveals the speciality that electronic scattering causes only an energy independent diminution of the intensity. For all other channels, complex resonance line shapes in the heterodyne/stroboscopic spectra - as a result of interference of electronic and nuclear scattering - is encountered. The grazing incidence case is evaluated and described in detail. Experimetal data of classical grazing incidence reflection and their stroboscopic detection on [natFe/57Fe]10 and antiferromagnetic [57Fe/Cr]20 multilayers are fitted simultaneously.