Determination of primary dose in 60Co gamma beam using a small attenuator.

A measurement technique previously proposed for determining dose from primary radiation has been tested using 60Co gamma rays. It is shown that the dose from primary radiation is reliably determined for field sizes of 10 X 10 and 20 X 20 cm2 at depths of 0.5, 5, and 10 cm in water. With further development this technique may be useful for verifying dose from primary radiation that may be calculated using a variety of methods.