Fig. 6

Single rates within the high-energy window (S_HE) as a function of the coincidence rate within the low-energy window (C_LE) for measurements performed with pure ¹⁸F (red dots), pure ⁶⁸Ga (blue dots), and a mixture of both radioisotopes (black dots). The results for the pure samples were fitted to a third-degree polynomial (blue and red lines for pure ⁶⁸Ga and ¹⁸F respectively). These fits are used as the calibration curves named as S_HE,F and S_HE,Ga in Eq. (2). Green squares represent the expected values for the mixture obtained using Eq. (2) and the theoretical relative activity (a_Ga,A)