This prototype delivers a signal proportional to the dose rate of the tube without disturbing its operation. Some prototypes of smart-windows have been integrated in an experimental X-Ray tube. Several experimental set-ups have been developed to test the detection properties in a tube-like design. Finally the mechanical resistance and the transparency of the devices have been characterized. A new tools has also been developed to monitor in real time and in situ the growth rate and the morphology of the films. Hence the experimental conditions have been optimized to increase the growth rate of the film. In order to integrate those windows experimentally, a small series must be realized. Two devices made either of polycrystalline or single crystal diamond were designed. The thermal, mechanical and sensing properties of such windows have been modeled by using a multi-domain approach.
The transmission windows fabricated in the context of this work are called “smart-windows”. The semi-conducting properties of diamond are used to integrate a built-in flow sensor and to monitor in-line the dose rate of the tube. It aims at studying, designing and synthesizing innovative diamond for X-Ray tubes. This thesis results from a collaboration between Thales and the french Atomic and Alternative Energies Commission (CEA). The beryllium used in those windows does not provide an efficient spreading of the heat generated in the target. In the race towards high resolution X-ray imaging, the current X-ray windows have shown thermal limitations.
We illustrate these advances for prototype chemical applications, including (i) stable near-equilibrium species, where resonance mixing typically provides only small corrections to a dominant Lewis-structural picture, (ii) reactive transition-state species, where strong resonance mixing of reactant and product bonding patterns is inherent, (iii) coordinative and related supramolecular interactions of the inorganic domain, where sub-integer resonance bond orders are the essential origin of intermolecular attraction, and (iv) exotic long-bonding and metallic delocalization phenomena, where no single “parent” Lewis-structural pattern gains preeminent weighting in the overall resonance hybrid. Such convexity-based algorithms now allow a full “reboot” of NRT methodology for tackling a broad range of chemical applications, including the many familiar resonance phenomena of organic and biochemistry as well as the still broader range of resonance attraction effects in the inorganic domain. Although earlier numerical applications were often frustrated by ineptness of then-available numerical solvers, the NRT variational problem was recently shown to be amenable to highly efficient convex programming methods that yield provably optimal resonance weightings at a small fraction of previous computational costs. We then outline the alternative “natural” pathway to localized Lewis- and resonance-structural conceptions that was initiated in the 1950s, given semi-empirical formulation in the 1970s, recast in ab initio form in the 1980s, and successfully generalized to multi-structural “natural resonance theory” (NRT) form in the 1990s. We first sketch the early roots of resonance theory, its heritage of diverse physics and chemistry conceptions, and its subsequent rise to reigning chemical bonding paradigm of the mid-20th-century. What is now called “resonance theory” has a long and conflicted history.
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