Measurement of neutron total cross sections at the VESUVIO spectrometer

Abstract

In this article we examine the procedures to determine total cross sections from neutron transmission experiments performed at the time-of-flight spectrometer VESUVIO (ISIS Pulsed Neutron and Muon Source, at the Rutherford Appleton Laboratory, UK). On the one hand we present a newly developed Python-based algorithm, running within the Mantid analysis environment, to obtain neutron total cross sections as a function of the incident neutron energy, employing the information recorded by the transmission monitor. We describe its basic operating principles and parameters, as well as its user interface, which is applied to a specific example of data processing on a set of graphite samples of different manufacturing processes. On the other hand, we discuss a series of features and recent upgrades that make VESUVIO the instrument of choice for accurate and broad-band thermal neutron cross section measurements.