Introducing DIANA: dual-mode imaging analysis open-source simulation software.

The use of the complementarity of the contrast between X-rays and neutrons for computed tomography is a well-established technique. X-rays are strongly attenuated by dense, high-atomic-number materials, while neutrons are particularly sensitive to light elements, such as hydrogen or lithium. Combining the information of both modalities into a two-dimensional histogram allows for the discrimination of material phases that would otherwise not be distinguishable with a single technique alone. Here we present DIANA (Dual-mode Imaging Analysis), an open-source Python package that implements a complete dual-modality CT simulation pipeline. The current version of the software builds a voxelised phantom, creates the radiographic projections for polychromatic X-rays and monochromatic neutrons, performs controlled artifact injection and reconstruction, and finally handles the visualisation of the 2D histogram and its analysis with both shape and quality metrics. To show the capabilities of DIANA, we demonstrate the application on a simple composite phantom and a clean, high resolution study of a realistic lithium-ion cell. The architecture of the package is extensible toward other modalities, such as polarised neutrons, phase-contrast X-rays or energy-resolved neutrons, among others. The package is hosted on Github under an MIT licence.