# A Versatile Velocity Map Ion-Electron Covariance Imaging Spectrometer for High-Intensity XUV Experiments

## TL;DR

This paper introduces a versatile VMI spectrometer designed for high-intensity XUV experiments, enabling covariance detection of photo-electrons and ions to obtain detailed molecular information.

## Contribution

The paper presents a novel VMI spectrometer capable of multiple detection modes for covariance analysis in high-intensity XUV experiments, including initial experimental results.

## Key findings

- Successful covariance detection with high-order harmonic generation source
- Enhanced capability for molecular frame or reaction-specific analysis
- Flexible detection modes for high-intensity XUV experiments

## Abstract

We report on the design and performance of a velocity map imaging (VMI) spectrometer optimized for experiments using high-intensity extreme ultraviolet (XUV) sources such as laser-driven high-order harmonic generation (HHG) sources and free-electron lasers (FELs). Typically exhibiting low repetition rates and high single-shot count rates, such~experiments do not easily lend themselves to coincident detection of photo-electrons and -ions. In order to obtain molecular frame or reaction channel-specific information, one has to rely on other correlation techniques, such as covariant detection schemes. Our device allows for combining different photo-electron and -ion detection modes for covariance analysis. We present the expected performance in the different detection modes and present the first results using an intense high-order harmonic generation (HHG) source.