Light-sheet imaging for the recording of transverse absolute density distributions of gas-phase particle-beams from nanoparticle injectors

TL;DR

This paper introduces a non-destructive light-sheet imaging technique for measuring the transverse density distribution of gas-phase nanoparticle beams, aiding in the optimization of biological molecule delivery.

Contribution

It presents a simple, effective method for characterizing particle beam profiles in parallel with diffraction experiments, using laser light sheets and Mie-scattering calibration.

Findings

Successfully demonstrated for 220 nm polystyrene beads

Enabled determination of particle flux and velocity distribution

Provides a new tool for optimizing nanoparticle beam delivery

Abstract

Imaging biological molecules in the gas-phase requires novel sample delivery methods, which generally have to be characterized and optimized to produce high-density particle beams. A non-destructive characterization method of the transverse particle beam profile is presented. It enables the characterization of the particle beam in parallel to the collection of, for instance, x-ray-diffraction patterns. As a rather simple experimental method, it requires the generation of a small laser-light sheet using a cylindrical telescope and a microscope. The working principle of this technique was demonstrated for the characterization of the fluid-dynamic-focusing behavior of 220 nm polystyrene beads as prototypical nanoparticles. The particle flux was determined and the velocity distribution was calibrated using Mie-scattering calculations.