Abstract: Radionuclides and radiation generating devices are general way to produce reference radiation fields. According to national standards, a reference γ radiation standard device has been constructed. Firstly, the structural composition, physical principle and technical route of the γ-ray Irradiation Facility were introduced. Secondly, the reference radiation filed of ⁶⁰Co source was measured by calibrated standard equipment. The measurement results show that the air kerma rate of the radiation field conforms well to the inverse square of the distance (R²≈1). The air kerma rate at 1 100 mm from the center of the source vary less 5% within 200 mm of field diameter, and the shutter transition time is about 0.74 s.

Key words: ⁶⁰Co source irradiation facility, air kerma rate, the inverse square of the distance R, uniformity of the radiation filed