In this work

the self-shielding effect of

125

I seed source was investigated.Adopting the direct and indirect methods

the self-shielding coefficients of

125

I seed source core

which were prepared under technical conditions of self-established palladium method

were measured.The results show that with certain surface areas of the adsorbing basal materials

the initial activities of adsorbing solution do not affect adsorbing rates of the basal materials

and the self-shielding coefficients of

125

I seed source core are about 64%

and the addition of NaS

2

O

3

makes the self-shielding effect coefficients decline greatly.