Relative Photoneutron Yields from the 330-Mev Bremsstrahlung

Relative photoneutron yields were determined for 50 elements bombarded by the 330-Mev x-ray bremsstrahlung of the Berkeley synchrotron. The determinations were made at 90° to the beam axis with a paraffin moderated B${\mathrm{F}}_3$ proportional counter. Relative yields for elements above atomic number 30 were proportional to $Z^{1.7}$. Yields for low $Z$ elements show a correlation with the binding energy of the last neutron. Angular distributions of photoneutrons were briefly investigated, and a Pb transition curve for photoneutrons was run.