Energy response of agar-alanine free radical dosimetry to therapeutic electron beams

Calculations of the energy response of an agar-alanine phantom dosimeter (AAPD) to electrons in the energy range of 0.15--20 MeV together with experimental results at 16 MeV are presented. It is shown that the sensitivity of the EPR dosimeter (EPR signal/Gray) is independent of alanine crystal size and varies less than 2%, in the electron energy range indicated. Thus, the measured free radical density distribution may be used directly as an indication of the absorbed dose distribution in an irradiated phantom