Excerpts on the physics...
Any grouping of electrically charged particles can radiate electromagnetic waves. Antennas emit radio waves, waveguide structures emit microwaves, electrons oscillating against the positive nuclei in atoms emit light and x rays, and protons and neutrons moving in the nuclei emit gamma rays. Once emitted, gamma rays are no different than x rays which often have the same energies. Since the oscillating charges in the nucleus emit their energy as short wavelength electromagnetic waves, this process is not a nuclear reaction. None of the interior particles of the nucleus escape to cause a nuclear reaction and the atom finishes as the stable (non-radioactive) ground state of the same isotope of the same element.

The nucleus is the smallest part of an atom which in turn is the smallest structural unit of physical matter. Thus, quantum mechanics teaches that the motions of the charged particles found within the nucleus will represent the highest velocities of circulation possible in a sample of any material. This is a fundamental precept that means that the very highest density of (non-nuclear) energy storage will be found in the motions of those charges in nuclei because they are confined in the smallest place known. Just as in the case of atoms, in a nucleus the movement of charges can absorb photons of electromagnetic waves, which in this case are x rays, and make a transition to an excited state of higher energy. ... in rare cases selection rules forbid the coupling of the particle motion to the electromagnetic field and then the high energies are stored for tens and even thousands of years in those special nuclei.

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Basically, these rare atoms store energy not in their electron energy states as is the principal used in getting materials to lase in lasers, but in the much denser, higher energy state of the nucleus. Amazing. I see this as a GREAT power source for deep space missions. Safer and far more powerful than RTGs.

-p (wants one for his home)