Calculated thickness of tungsten alloy required for specified attenuation of gamma radiation from /sup 137/Cs

The traditional method of evaluating and calibrating health physics instruments is to use a calibrator that consists of a single high-activity gamma radiation level desired for testing. To have accurate radiation intensities inside the calibrator cavity, the attenuator must be designed from precise absorption calculations. The authors report calculations made to determine the thickness of tungsten alloy metal required for specific attenuation. These calculations include the buildup contribution by secondary scattering radiation, and they are compared to values calculated with the buildup factor omitted.<
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