V2:Performance of the solid deuterium ultra-cold neutron source at the pulsed reactor TRIGA Mainz

TL;DR

This paper reports on the performance of a solid deuterium ultra-cold neutron source at TRIGA Mainz, highlighting its neutron yield, density, and efficiency, and comparing results with Monte Carlo simulations for future upgrades.

Contribution

It provides detailed performance metrics of a solid deuterium UCN source and validates simulation models for optimizing future neutron source upgrades.

Findings

Up to 550,000 UCN per pulse produced

UCN densities of ~10/cm3 achieved in storage bottles

Measured yields agree with Monte Carlo predictions

Abstract

The performance of the solid deuterium ultra-cold neutron source at the pulsed reactor TRIGA Mainz with a maximum peak energy of 10 MJ is described. The solid deuterium converter with a volume of V=160 cm3 (8 mol), which is exposed to a thermal neutron fluence of 4.5x10^13 n/cm2, delivers up to 550 000 UCN per pulse outside of the biological shield at the experimental area. UCN densities of ~ 10/cm3 are obtained in stainless steel bottles of V ~ 10 L resulting in a storage efficiency of ~20%. The measured UCN yields compare well with the predictions from a Monte Carlo simulation developed to model the source and to optimize its performance for the upcoming upgrade of the TRIGA Mainz into a user facility for UCN physics.