# A Numerical Approach to Designing a Versatile Pepper-pot Mask for Emittance Measurement

## TL;DR

This paper presents a numerical approach to designing a versatile pepper-pot mask for emittance measurement, focusing on beam dynamics in space charge regimes and optimizing mask geometries through simulations.

## Contribution

It introduces a tracking code for testing pepper-pot setups and provides analytical criteria for mask design tailored to high-intensity, low-energy beams.

## Key findings

- Optimized mask geometries improve emittance measurement accuracy.
- Simulation results validate the analytical design criteria.
- Beam dynamics insights enhance pepper-pot method effectiveness.

## Abstract

The pepper-pot method is a popular emittance measurement technique for high intensity beams at low energy such as those generated by photo-injectors. In this paper, the beam dynamics in the space charge dominated regime and analytical design criteria for a mask-based emittance measurement (pepper-pot method) are revisited. A tracking code developed to test the performance of a pepper-pot setup is introduced. Examples of such testing are presented with particle distributions that were generated using PARMELA under different focusing conditions. These distributions were numerically tested against a series of mask geometries suggested by analytical criteria. The resulting fine-tuned geometries and beam dynamics features observed are presented.