Dosimetry of Ultra-High Dose-Rate Electron Beams at Solid-Water Interfaces in Electron Microscopy: A Key Advance in Hydrated Samples Research

Introduction

Electron microscopy (EM) has played a key role in the discovery of many new materials, as well as the elucidation of the role of defect structures and interfaces on material properties and behaviour. Current electron microscopes are capable of maintaining the relevant hydrated state of samples by means of cryofixation techniques or by using dedicated liquid cells.

Importance of Aqueous Systems

This opens up the possibility of investigating crucial interfaces, such as those in complex aqueous systems that, despite their significance, remain poorly understood. The study of water-solid interfaces in the EM is currently limited by the sensitivity of aqueous samples and interfaces to the action of the electron beam.

Need for Fundamental Knowledge

Knowledge of the fundamental chemical processes induced by interaction with the electron beam is needed for the interpretation of results, prediction and design of experiments, and to potentially mitigate electron-beam effects.

Proposed Development

Here, I propose to develop novel instrumentation and approaches to allow for the direct determination of the yields of radicals and molecules produced, as well as reaction kinetics in the EM and at the interface between materials and aqueous solutions.

Objectives and Methodology

This new concept will permit us to precisely assess the effect of important factors in the radiolysis of aqueous solutions inside the EM, such as:

1. The very high electron dose rates
2. The supports
3. Liquid volume
4. Temperature
5. The effect of nanomaterials interfaces

This newly accessible knowledge will lead to the interpretation of numerous EM experiments and will be used to develop novel data-informed adaptive scanning approaches specifically designed for in situ dynamic acquisition with minimal chemical effects in the samples.

Future Goals

An important goal of this project is to conceive new predictive models for the radiolytic chemistry produced during EM experiments, which will open the door to the future design of mitigation procedures for radiolysis damage in EM.