Evaluating laser-driven Bremsstrahlung radiation sources for imaging and analysis of nuclear waste packages

A small scale sample nuclear waste package, consisting of a 28 mm diameter uranium penny encased in grout, was imaged by absorption contrast radiography using a single pulse exposure from an X-ray source driven by a high-power laser. The Vulcan laser was used to deliver a focused pulse of photons to a tantalum foil, in order to generate a bright burst of highly penetrating X-rays (with energy >500 keV), with a source size of <0.5 mm. BAS-TR and BAS-SR image plates were used for image capture, alongside a newly developed Thalium doped Caesium Iodide scintillator-based detector coupled to CCD chips. The uranium penny was clearly resolved to sub-mm accuracy over a 30 cm2 scan area from a single shot acquisition. In addition, neutron generation was demonstrated in situ with the X-ray beam, with a single shot, thus demonstrating the potential for multi-modal criticality testing of waste materials. This feasibility study successfully demonstrated non-destructive radiography of encapsulated, high density, nuclear material. With recent developments of high-power laser systems, to 10 Hz operation, a laser-driven multi-modal beamline for waste monitoring applications is envisioned

Advanced laser micro-structuring of super-large-area optical films

A novel laser micro-machining technique to produce high density micro-structures called Synchronized Image Scanning (SIS) was introduced a couple of years ago. Over this period of time, the technique was refined in a major effort to meet the needs of various industries. There is an increasing demand for micro-structuring of large and super large area optical films, e.g. for Rear Projection TV, anti counterfeit packaging material and 3D displays. Especially in the display industry, where the screens are ever increasing in size, established micro-structuring methods like e-beam milling, diamond turning or the reflow technique struggle to keep up with the development. This paper explains how it is possible to direct laser etch hundreds of millions of lenses into a 2 m x 1.5 m substrate. It looks at the advances made in SIS in recent years regarding seam reduction, overall accuracy and precision when structuring super large area optical films, and it presents the tools and subsystems needed to generate the features in those films. Furthermore, the potential of this exciting laser micro-machining technique for rapid prototyping for all sorts of optical and non-optical structures is mapped out

New techniques for laser micromachining MEMS devices

Two new laser mask projection techniques Synchronized Image Scanning (SIS) and Bow Tie Scanning (BTS) have been developed for the efficient fabrication of dense arrays of repeating 3D microstructures on large area substrates. Details of these techniques are given and examples of key industrial applications are shown