Preventive ion beam inspection of glass treasures

Art objects made of glass may undergo deterioration when exposed to environmental stress. Even in air conditioned museums, susceptible glass surfaces may decompose. Thus, their transparency is reduced and initial tiny surface cracks may result in irreplaceable loss of glass. Degradation takes place via ion exchange reactions between the silicate network and the humidity of the ambient atmosphere. Endangered glass objects in important collections should be studied using non-destructive analytical methods. In this regard, the advantage of ion beam analysis by simultaneous Particle Induced Gamma-ray Emission (PIGE), Particle Induced X-ray Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS) in a non-vacuum facility is demonstrated. This paper is concerned with both the current condition of the glass surface and the composition of the bulk of the glass. The result of such ion beam examination enables the scientist to recommend suitable storage conditions. In addition, the non-destructive study provides scientists studying art objects with means of objective material identification, enabling them to reach conclusions with respect to particular glass technologies or proveniences.