Author/Authors :
Umehara، نويسنده , , S and Fushimi، نويسنده , , K and Koori، نويسنده , , N and Kudomi، نويسنده , , N and Kume، نويسنده , , K and Kuramoto، نويسنده , , H and Nakayama، نويسنده , , S and Shimojo، نويسنده , , T and Takahisa، نويسنده , , K and Tsubakida، نويسنده , , R and Tsujimoto، نويسنده , , Y and Yoshida، نويسنده , , S، نويسنده ,
Abstract :
We have accurately determined U-chain concentration in a detector by means of the β–α delayed coincidence method. This method can measure the radioactivity of the order of 10−7 Bq/kg. It corresponds to the concentration of the order of 0.01 ppt under the assumption that the U-chain is in the secular radioactive equilibrium, by a signal-to-noise ratio of one to one.
