Target theory applied in the radiation damage analysis for organic detectors.

The target theory was used to explain the radiation damage in samples containing 1% (g//L) of 2,5- diphenil-oxazolyl (PPO) diluted in toluene and irradiated with ⁶⁰Co (1.8 Gy/s). The survival molecules of irradiated PPO following the bi- exponential mathematical model [0.743xexp(-D/104.3) + 0.257xexp(-D/800)]. It indicates that a fraction 0.743 of the molecules decay with D₃₇=104.3 kGy and 0.257 decay with D37=800 kGy. From the Target Theory it was inferred the energies involved in the irradiation damages, which were 0.0363 plusmn 0.004 eV (G=3.63 plusmn 0.402 damages/100 eV) and 0.0959 plusmn 0.0492 eV (G=9.59 plusmn 4.92 damages/100 eV). The diameter of PPO molecule estimated from the Target Theory was in the interval of 45.5 to 64.9 Aring.