Fig. 5.

Plot of experimental and theoretically calculated relative response for ¹³³Ba solution filled cylinders in the NIST Vinten 671 ionization chamber (VIC). For the experimental data (solid diamonds), the relative response, R(norm), is defined as the ratio of the average measured ionization current per unit activity (in A/Bq) for all sources in a particular volume set to that of the average measured ionization current for the sources having a nominal volume of 6 mL. For the theoretical data (open triangles), the relative response is given as the ratio of the dose per particle calculated from the DOSRZnrc simulations for each volume to that of the dose per particle calculated for the source having a nominal volume of 6 mL. All uncertainty bars correspond to single (k = 1) uncertainty intervals and their method of evaluation is described in Sec. 3.3.