Standardization of 177 Lu by means of 4π(LS)β-γ coincidence and anti-coincidence counting

The activity concentration of a 177 Lu solution was measured by the Laboratory of Radioactivity Standards in the Radioisotope Centre POLATOM. The solution was measured by means of 4 πβ (LS)- γ coincidence and anticoincidence counting. Both methods gave consistent results of the activity concentration, a relative standard uncertainty of 0.24% was obtained, which is much smaller than the uncertainty of previous measurement performed within the scope of the international comparison CCRI(II)-K2.Lu-177 in 2009. To establish a more precise calibration factor of a 4π ionization chamber for this isotope, the obtained result of activity concentration was used.