I have found an x-ray laser device to be an interesting subject. In the Free-electron laser system a relativistic velocity electron stream interacts with a magnetic structure that contains fixed magnets to produce x-ray frequency radiation. It does not take too much imagination to visualize how the incredibly intense fields that we suspect exit in close proximity to the nuclei would be able to encourage the emission of similar radiation.
The frequency of emissions depends upon a multitude of variables such as the strength of the magnetic field. Spin coupling as some have suggested would likely be another important parameter. In the Free-electron laser, an example of how a positive feedback mechanism leads to interaction among the energetic moving charges is made apparent. Of course the atoms involved in the LENR reaction would not utilize the same process, but I suspect another equally interesting interaction will be uncovered. See: http://en.wikipedia.org/wiki/Free_electron_laser Dave
