Beamline Simulation for the NNBAR Experiment at the European Spallation Source

TL;DR

This paper introduces a new sampling method for simulating the NNBAR beamline at the European Spallation Source, enabling high-statistics, correlated neutron track simulations for fundamental physics experiments.

Contribution

A novel sampling technique based on probability density evaluation and duct source biasing for efficient, high-fidelity beamline simulations.

Findings

Enables comprehensive simulation of the entire NNBAR beamline

Preserves correlations of neutron tracks in simulations

Achieves high statistics in beamline modeling

Abstract

The HIBEAM and NNBAR experiments are a proposed fundamental science experiments at the European Spallation Source, performing high precision searches for neutron conversions in several baryon number violating (BNV) channels. For simulations of the NNBAR beamline, a new sampling method has been developed. The method is based on probability density evaluation and duct source biasing and enables the simulations of the entire NNBAR beamline with high statistics while also preserving correlations of the neutron tracks.