The S value for homogeneous distribution of radioiodine in the lumen of the human single follicle model. The S value and the relative contributions from the non-radiative transitions for homogeneously distributed radioiodine within the follicle lumen. The follicle lumen diameter varied from 10 to 500 μm surrounded by one single layer of follicle cells with a thickness of 10 μm and centrally placed 8 μm diameter follicle cell nucleus. (a) The S value for the follicle cell nucleus for 123I (square), 125I (triangle) and 131I (circle), as a function of the follicle lumen diameter. (b to d) The relative contribution per decay to the follicle cell nucleus from Auger electrons (AE) (triangle), internal conversion electrons (CE) (square), β particles (diamond), as a function of the follicle lumen diameter, for (b)123I, (c)125I and (d)131I. Error bars indicate the standard deviation of the mean value (SD) and are smaller than the symbol when not visible. Note the logarithmic scale on the ordinate in (a).