On the Gamma-Ray One-Shot-Collimator Measurement of Two-Phase-Flow Void Fractions

Equations are derived to determine the optimum design parameters (minimum error) for the gamma-ray one-shot-collimator method of measuring average void fractions in two-phase flow. A compromise is indicated between the desirability of response linearity cm the one hand and maximum sensitivity on the other. Results from a prototype gauge using the 60-keV gamma rays from ²⁴¹Am are given for void fractions of extreme distributions within a circular channel and are compared to a previous gauge that used a ¹⁷⁰ Tm source.