1. The relative mass resolution is by no means the only concept which may be used to define a measure of performance. In much design work of nuclear assay systems the degree of “flatness” of the response function has been used as a measure of performance. An additional useful and widely employed design concept is the resolving power. See:
2. A. Notea and Y. Segal, A General Approach to the Design of Radiation Gauges, Nucl. Tech., 14: 73 – 80 (1974).
3. Y. Segal, A. Notea and E. Segal, A Systematic Evaluation of Nondestructive Testing Methods, in Research Techniques in Nondestructive Testing, Vol. Ill, R. S. Sharpe, ed., Academic Press, 1977.
4. N. Shenhav, Y. Segal and A. Notea, Application of Neutron Count Moment Analysis Method to Passive Assay, Nucl. Sci. Eng., 80: 61 – 73 (1982).
5. The concept of the response function does not require that the detector be localized at a single point. It is meaningful for well‐ type counters which entirely surround the sample and for calori‐ metric measurements. For an interesting exploitation of the sensitivity of a Nal well‐type counter to the spatial distribution within the well of a gamma source see