# Set-up for multi coincidence experiments of EUV to VIS photons and charged particles -- the solid angle maximization approach

## TL;DR

This paper introduces optical assemblies that significantly increase the solid angle for EUV to VIS photon detection, improving coincidence detection efficiency in experiments involving neutral particles or photons.

## Contribution

The paper presents novel optical assemblies that enhance solid angle coverage for photon detection in coincidence experiments, enabling better detection of neutral particles and photons.

## Key findings

- Enhanced solid angle for EUV to VIS photons
- Improved electron-photon coincidence detection efficiency
- Demonstrated versatility with synchrotron radiation experiments

## Abstract

The coincident detection of particles is a powerful method in experimental physics, enabling the investigation of a variety of projectile-target interactions. The vast majority of coincidence experiments is performed with charged particles, as they can be guided by electric or magnetic fields to yield large detection probabilities. When a neutral species or a photon is one of the particles recorded in coincidence, its detection probability typically suffers from small solid angles. Here, we present two optical assemblies considerably enhancing the solid angle for EUV to VIS photon detection. The efficiency and versatility of these assemblies is demonstrated for electron-photon coincidence detection, where electrons and photons emerge from fundamental processes after photoexcitation of gaseous samples by synchrotron radiation.