"In the first step of the process, the ion energy from radioisotopes is transported to an intermediate photon generator called a fluorescer and produces photons, which are the basic units of light."
"In the second step of the process, the photons are transported out of the fluorescer to photovoltaic cells, which efficiently convert the photon energy into electricity."
"A method which eliminates the radiation damage problem is a Two-Step Photon Intermediate Direct Energy Conversion (PIDEC) method that uses the efficient generation of photons from the interaction of particulate radiation with fluorescer media."