{alpha}-decay half-life of {sup 253}Es in metallic Fe at temperatures between 4 K and 50 mK

It has been claimed recently that half-lives of radioactive nuclei embedded in metals would be significantly affected by electron screening provided by the metal. The effect would further be strengthened at low temperatures. We have determined the half-life-of {sup 253}Es nuclei embedded in iron at temperatures between 4 K and 50 mK. Our results agree with the room temperature literature value within about 2% and show no dependence on temperature over a range of almost two orders of magnitude.