hv2-concept breaks the photon-count limit of RIXS instrumentation

TL;DR

The hv2-concept in RIXS instrumentation allows for using the entire core-hole lifetime window of incident synchrotron radiation, overcoming traditional photon-count limits while maintaining energy-loss resolution.

Contribution

This paper introduces the hv2-concept, a novel RIXS approach that breaks the photon-count limit by leveraging the invariance of spectra over incident energies within the core-hole lifetime.

Findings

RIXS spectra are invariant to incident energy integration within the core-hole lifetime.

The hv2-concept enables full utilization of the incident radiation without resolution loss.

Photon-count limits in RIXS are effectively surpassed.

Abstract

Upon progressive refinement of energy resolution, the conventional RIXS instrumentation reaches the limit where the bandwidth of incident photons becomes insufficient to deliver an acceptable photon-count rate. We show that the RIXS spectra as a function of energy loss are essentially invariant to their integration over incident energies within the core-hole lifetime. This fact permits the RIXS instrumentation based on the hv2-concept to utilize incident synchrotron radiation over the whole core-hole lifetime window without any compromise on the energy-loss resolution, thereby breaking the photon-count limit.