Neutron Radiography and Tomography

Abstract

This entry gives an introductory overview of the application of the modern well‐established neutron and X‐ray imaging methods to museum objects and related materials. Since both kinds of radiation complement each other often in their interaction with matter, a combination of the image data can provide the perfect noninvasive picture of inner contents and structures. In the framework of this entry, we can only show some principles and examples from studies, while details are referenced and given in the literature. More advanced techniques are under development and will be implemented into the routine work on demand. We mention them here for completeness.

Restoration of Radiographic Neutron Image Using Single-Channel Blind Deconvolution

“…Using the standard blind deconvolution MAPestimation model in (2), a new image prior P(L) is proposed. The aim is to enforce sparsity of image prior, which helps accelerate the recovery of the intermediate latent image L during the iteration process of PSF estimation.…”

“…This imaging technique excels in materials characterization, defect detection, and analysis of various opaque objects particularly useful for imaging materials that are difficult to penetrate with X-rays, such as metals or materials with high atomic numbers. Neutrons have high penetration capabilities into all types of materials, including heavy metals, and are sensitive to many light elements, especially hydrogen [1][2][3] Although powerful and unique, neutron images from low-power research reactors are usually degraded. Even though there are several factors responsible for this degradation, the problem is mainly due to the beam collimation ratio which is not sufficiently large in order to make a parallel beam a valid assumption for NR projection.…”