Studies in useful hard x-ray induced chemistry

The observed rapid decomposition of potassium chlorate (via 2KClO$_{3}+$ h$\nu \to $ 2KCl $+$3O$_{2})$ via synchrotron hard x-ray irradiation (\textgreater 10 keV) has enabled experiments that are developing novel and useful hard x-ray chemistry. We have observed a number of radiation-induced \textit{in situ} decomposition reactions in various substances which release O$_{2}$, H$_{2}$, N$_{2}$, NH$_{3}$, and H$_{2}$O in a diamond anvil cell (DAC) at ambient and high pressures. These novel acatalytic and isothermal reactions represent a highly controllable, penetrating, and focused method to initiate chemistry (including x-ray induced combustion) in sealed and/or isolated chambers which maintain matter under extreme conditions. During our studies, we have typically observed a slowing of decomposition with pressure including phase dependent decomposition of KClO$_{3}$. Energy dependent studies have observed an apparent resonance near 15 keV at which the decomposition rate is maximized. This may enable use of much lower flux and portable x-ray sources (e.g. x-ray tubes) in larger scale experiments . These developments support novel means to load DACs and control chemical reactions providing novel routes of synthesis of novel materials under extreme conditions.