Gamma Radiation from the Nickel Nanopowder

For gamma energy in the order of 6 MeV, the wavelength is about 0.2 pm. This wavelength is a few orders smaller than the gaps between the nanopowder particles. The gas occupying the gaps has a refractive index close to one, while the refractive index of the nanoparticle material for the wavelength of 0.2 pm is much higher. Then the emitted gamma rays from the nickel nanopowder in the bulk will undergo multiple reflections, refractions and absorption, so the energy they loose will be converted to heat. Some proper attenuated gamma rays will produce Rydberg hydrogen that is useful for the cold fusion. Only not absorbed attenuated gamma rays may escape the fuel powder, so they must be shielded.
Tungsten alloy material is suitable for gamma radiation protection, for more details, you could visit http://www.tungsten-alloy.com/tungsten-alloy-radiation-shielding.html.