Virtual-Diagnostic-Based Time Stamping for Ultrafast Electron Diffraction

TL;DR

This paper introduces a virtual diagnostic method for non-invasively measuring electron beam timing and energy in ultrafast electron diffraction, aiming to enhance temporal resolution and stability in experiments.

Contribution

It presents a linear regression model for predicting beam timing and energy using virtual diagnostics, with potential for further improvements via machine learning techniques.

Findings

Accurately predicts beam time of arrival and energy.

Separates shot-to-shot jitter from long-term drift.

Enhances temporal resolution in ultrafast electron diffraction.

Abstract

In this work, non-destructive virtual diagnostics are applied to retrieve the electron beam time of arrival and energy in a relativistic ultrafast electron diffraction (UED) beamline using independently-measured machine parameters. This technique has the potential to improve temporal resolution of pump and probe UED scans. Fluctuations in time of arrival have multiple components, including a shot-to-shot jitter and a long-term drift which can be separately addressed by closed loop feedback systems. A linear-regression-based model is used to fit the beam energy and time of arrival and is shown to be able to predict accurately behavior for both on long and short time scales. More advanced time-series analysis based on machine learning techniques can be applied to improve this prediction further.