Second-Difference Analysis of Bremsstrahlung Yield Curves

The second-difference weighting function of the bremsstrahlung spectrum obtained from an empirical isochromat at 15.1 Mev and corrected for thick-target effects is shown to behave like a delta function of width approximately equal to the energy interval in analysis. This behavior greatly simplifies cross-section analysis of bremsstrahlung-induced activation curves when resonance phenomena are present. Application of the method to preliminary yield data for the ($\gamma , n$) reaction in nitrogen and oxygen gives good agreement with known level structure.