Post-sample aperture for low background diffraction experiments at X-ray free-electron lasers.

Max O Wiedorn,Niko Eckerskorn,Anton Barty,Richard Bean,Nils Roth,Henry N Chapman,Saša Bajt,Richard A Kirian,Daniel A Horke,Valerio Mariani,Leonard M G Chavas,Andrew J Morgan,Salah Awel,Jochen Küpper,Oleksandr Yefanov,Kenneth R Beyerlein,Dominik Oberthür,Andrei Rode ,Michaël Heymann ,Miriam Barthelmeß ,J Knoška ,H Fleckenstein

doi:10.1107/s1600577517011961

Abstract

The success of diffraction experiments from weakly scattering samples strongly depends on achieving an optimal signal-to-noise ratio. This is particularly important in single-particle imaging experiments where diffraction signals are typically very weak and the experiments are often accompanied by significant background scattering. A simple way to tremendously reduce background scattering by placing an aperture downstream of the sample has been developed and its application in a single-particle X-ray imaging experiment at FLASH is demonstrated. Using the concept of a post-sample aperture it was possible to reduce the background scattering levels by two orders of magnitude.

Highlights

The success of diffraction experiments from weakly scattering samples strongly depends on achieving an optimal signal-to-noise ratio
This is important in single-particle imaging experiments where diffraction signals are typically very weak and the experiments are often accompanied by significant background scattering
A simple way to tremendously reduce background scattering by placing an aperture downstream of the sample has been developed and its application in a single-particle X-ray imaging experiment at FLASH is demonstrated

Summary

Introduction

The success of diffraction experiments from weakly scattering samples strongly depends on achieving an optimal signal-to-noise ratio. This is important in single-particle imaging experiments where diffraction signals are typically very weak and the experiments are often accompanied by significant background scattering.

Results

Conclusion