Counting rate of spherical ion exchange resin containing 32P homogeneously

Radioactivity from a spherical ion exchange resin containing radioisotopes homogeneously was calculated. For the calculations a mean distance defined by the length from an arbitrary point in the sphere to the spherical surface was used. The radioactivity to be radiated from the point in the mean distance and observed at the surface of the sphere was estimated in the form of integrals, considering a relative intensity obtained from the use of the mean distance. The integral was performed from the center of the sphere to the radius using a numerical method. Homogeneous adsorption of 32P in a spherical ion exchange resin (Amberlite IRA-425) was carried out as H2PO4- labeled with 32P. β-rays of 32P transmitting through the resin were measured. The numbers of 32P adsorbed in the sphere were calculated from the concentration decrease of a H2PO4- solution in an adsorption flask. The estimated radioactivity was in good agreement with the observed one. (auth.)