Table 3.

Comparison of radial dose function g_L(r) of the new BEBIG ⁶⁰Co HDR source in water and four water-equivalent solid phantom materials. The dimensions of cylindrical phantom are 100 cm diameter × 100 cm height

Distance r(cm)	gL(r)
	Water	PMMA	Polystyrene	RW1	Solid Water
0.2	1.014	1.016	1.014	1.014	1.014
0.3	1.010	1.012	1.010	1.010	1.010
0.4	1.008	1.010	1.009	1.008	1.009
0.5	1.007	1.008	1.007	1.007	1.007
0.6	1.003	1.004	1.004	1.004	1.003
0.7	1.002	1.003	1.002	1.002	1.002
0.8	1.001	1.002	1.001	1.001	1.001
0.9	1.001	1.002	1.001	1.001	1.001
1	1.000	1.000	1.000	1.000	1.000
1.2	0.996	0.996	0.996	0.997	0.996
1.4	0.992	0.992	0.992	0.993	0.992
1.5	0.992	0.992	0.992	0.993	0.992
1.8	0.987	0.985	0.986	0.987	0.987
2	0.985	0.983	0.986	0.985	0.985
2.5	0.979	0.976	0.979	0.979	0.979
3	0.972	0.965	0.970	0.972	0.971
3.5	0.960	0.957	0.962	0.961	0.961
4	0.957	0.946	0.957	0.957	0.957
4.5	0.947	0.939	0.948	0.949	0.948
5	0.940	0.932	0.941	0.940	0.940
6	0.926	0.919	0.928	0.926	0.927
7	0.918	0.905	0.920	0.918	0.918
8	0.900	0.880	0.905	0.900	0.901
9	0.882	0.866	0.883	0.883	0.882
10	0.860	0.840	0.871	0.862	0.863
11	0.841	0.818	0.852	0.845	0.844
12	0.820	0.799	0.830	0.822	0.821
13	0.799	0.770	0.809	0.802	0.801
14	0.788	0.749	0.796	0.789	0.786
15	0.759	0.732	0.772	0.763	0.760
18	0.708	0.665	0.716	0.705	0.703
20	0.663	0.625	0.681	0.658	0.657

The radial dose function of BEBIG new HDR ⁶⁰Co source in water has been fitted to a 3^rd order polynomial between r = 0.2 − 20 cm. The co-efficients obtained as a₀ = 1.0118, a₁ = −0.01225 cm⁻¹, a₂ = −3.39297 × 10⁻⁴ cm⁻² and a₃ = 3.9995 × 10⁻⁶ cm⁻³.