Czeching Out Progress in Glasses – (Theme II: Glasses and Glass-Ceramics)

 

Last September, I attended the “13th International Symposium on Non-Oxide and Novel Optical Glasses” which was held in Pardubice in the Czech Republic. The conference name is quite a mouthful so it is usually abbreviated to IS(NOG)^2. The intention in the lengthy name is to distinguish the the work presented at this conference, which is concerned with high-tech, telecommunications type glasses from that on more mundane window, drinking and spectacle-type glasses.

The fact that it was the 13th such conference in the series might have been tempting fate, because a few weeks before the conference a substantial section of down-town Prague and several other European cities on the same river system were inundated in the great floods of 2002. The conference had a few cancellations, even though Pardubice is 100km east of Prague and on a different river system.

However, there were still about 200 attendees present, and a wide range of talks were presented, from numerical simulations of amorphous solids to glass-ceramic lenses for infra-red satellite sensing. Grant Williams (IRL) and I presented our latest results on glass-ceramic X-ray storage phosphors (see the insets). Often at conferences, the benefits are not just the presentations, but also the people that you meet. In this case it turned out that one of the audience had been involved in the development of the competing amorphous selenium X-ray imaging technology, so it was very useful to be able to talk to him about the background to that work and the developments in it. Whilst in Europe, I also visited Utrecht and Delft Universities in Holland, who have interests in spectroscopy, radiation imaging and detection, which parallel ours, and reinforced some useful contacts. Delft have a research reactor which may be useful when we come to measure the response of glasses designed for thermal neutron imaging.

Closer to home, I also attended the Non-Destructive Testing Association’s annual conference in October, held in Hamilton, and gave a review paper from Grant and myself on X-ray imaging in general, and storage phosphors in particular. Some of our funding comes from NERF (New Economy Research Fund), and so we are asked to stay in close contact with potential users of the technology that we are supporting and developing. We have already had discussions with hospital physicists regarding medical radiography applications, but at this conference we had the opportunity to talk to the people involved in another main area of application: industrial radiography. Examples of applications in this area include crack detection in pipelines and in aircraft structures (quite important for the traveling public!). There were several offers of access to the rather powerful gamma and X-ray sources which they use, which will be quite helpful when we extend our work to gamma ray imaging. One paper at the conference, by Christine Thompson of Agfa, discussed the rather novel application of X-ray storage phosphors to art history – the technology is sufficiently sensitive to reveal early “drafts” of paintings buried underneath the final version – with the “non-destructive” tag being quite important when it comes to a Ruebens for example!

A final application – security X-rays for freight containers – we haven’t found a conference for, and anyway have some doubt that we can fabricate a prototype glass imaging plate of the correct size!

Dr Andy Edgar is at the School of Chemical and Physical Sciences, Victoria University of Wellington – andy.edgar@vuw.ac.nz

An X-ray image of internal transistor structure recorded using a section of glass-ceramic imaging plate.  the image is recorded as a blue light emission after teh X-irradiated plate is bathed in red light – the process of “photo-stimulated luminescence.”

 

 

 

 

 

 

The same transistor photographed above the section of imaging plate.