Single shot emittance measurement using Optical Transition Radiation

TL;DR

This paper presents a novel single-shot method for measuring electron beam emittance using four Optical Transition Radiation screens near a beam waist, enabling rapid and accurate characterization of high-energy beams.

Contribution

The paper introduces a new setup employing four OTR screens and a fitting procedure to reconstruct beam emittance in a single shot, validated through simulations.

Findings

The method accurately reconstructs emittance in simulations.

Sensitivity analysis shows robustness to measurement errors.

Inclusion of scattering effects in simulations enhances reliability.

Abstract

We describe a method that uses Optical Transition Radiation (OTR) screens to measure in a single shot the emittance of an electron beam with an energy greater than 100 MeV. Our setup consists of 4 OTR screens located near a beam waist. A fit of the 4 profiles allows the reconstruction of the Twiss parameters and hence a calculation of the beam emittance. This layout has been simulated using Mathematica to study its sensitivity to errors and using Geant4 to include effects due to the scattering of the electrons in the screens. Some assumptions made in this document are conservative to allow for unexpected experimental issues.