PURPOSE: To improve the crystalline condition and the reproductivity by using a hardened palladium made by applying a cold process of a reduction in area in a specific rate or higher to a palladium material as a heavy hydrogen storage substance used for a normal temperature fusion reaction.

CONSTITUTION: A palladium metal of 6.5kg with the purity 99.95% is melted in the atmosphere by a high-frequency wave to cast an ingot of the diameter 43mm and the length 370mm, which is soaked in a liquid nitrogen, and after a boiling phenomenon is calmed down, it is picked up from the liquid nitrogen, processed into a body of the diameter 10mm by a swaging process, the metal is soaked again in the liquid nitrogen, and after a boiling phenomenon is calmed down, it is picked up from the liquid nitrogen, a die wire drawing process is applied, and such a process is repeated to process up to the diameter 2.0mm. And by using a hardened palladium material to which a cold process of a reduction in area of 70% or more has been applied, a normal temperature nuclear fusion reaction experiment is carried out. As a result, the diffusion coefficient is increased, the diffusion speed, the absorption speed, and the transmission speed of the heavy hydrogen are increased, and the reproductivity can be improved.