Monitoring the Condition of Played Historical Brass Instruments by Means of Neutron Imaging

Neutron imaging is a non-destructive testing method that functions according to principles similar to X-ray imaging. In contrast to X-rays, neutrons can generally penetrate metals rather well, but at the same time they have a high sensitivity for hydrogen. This makes neutron imaging – which includes radiography (investigations in 2D) as well as tomography (3D) – an ideal method for studying the impact of playing historical brass instruments. Playing a brass instrument creates an accumulation of moisture inside the instrument, which can eventually lead to the generation and expansion of corroded areas inside it. This moisture, along with many other products of corrosion, contains hydrogen, which provides a high degree of contrast for neutron imaging. This article explains how neutron imaging was used to monitor the condition of historical brass instruments, i.e. the changes in the internal corroded areas, by comparing 3D CT-data sets acquired before and after the instruments had been played on a regular basis over the period of fourteen months.