Calibration of Gammacell 220 E Irradiator Using Fricke and Alanine Dosimeters

Abstract

Using of Gammacell 220 Excel irradiators is widely spread in many countries. This type of irradiators is being used for research purposes. Gammacell 220 Excel was provided by the International Atomic Energy Agency (IAEA) to the Radiation Processing laboratory of Sudan Atomic Energy Commission (SAEC). It is a self-contained gamma irradiator and self shielded, this makes it operates safely. Dose calibration for this cell is important for samples irradiation. In this work, a dosimetry system for the GC220E of SAEC was established using Fricke dosimeter. Fricke dosimeter has a confidence 95% in the range not exceed 400 Gy. To establish routine dosimetry at high doses up to 5000 Gy, Alanine dosimeter was used. This range can demonstrate the ability of GC220E to deliver known controllable doses in reproducible manner for high doses. The irradiation specifications often include a lower and upper limit of absorbed dose or central target dose. Absorbed dose mapping was carried out by both dosimeters to determine the magnitude and locations of D.max and D.min in the irradiation chamber. The results are in good agreement with dose distribution given in the machine manual. A comparison between the tow dosimeters was done and explained.