# Study and perspective on neutron beam divergence improvement achievable by the combination of two or more neutron collimating systems

## TL;DR

This paper investigates how combining multiple neutron collimating systems can improve beam divergence, supported by experimental results and a new theoretical model, with implications for broader neutron beam applications.

## Contribution

It introduces a new theoretical approach to quantify neutron beam divergence improvements from combined collimators, validated by experimental data at PSI BOA.

## Key findings

- Combining collimators reduces neutron beam divergence.
- Experimental results confirm theoretical predictions.
- The approach has broader applicability beyond PSI BOA.

## Abstract

This communication presents the results obtained at an experimental campaign at PSI BOA beamline using the combination of the ANET Compact Neutron Collimator (CNC) with the actual BOA pin-hole system. Through extensive resolution campaigns, it has been possible to quantify and understand the effects of improvement on the beam divergence when combining the two collimating systems. A new theoretical approach to this problem is described and discussed. The effect is expected not to be limited to the specific case that has been studied at PSI BOA but to have a more general validity for neutron collimation systems.