Neutron transmission measurements have been made on many of the nuclides whose atomic weights lie between 45 and 75. Parameters of individual resonances were deduced for some of these nuclides and for all of them a value of the strength function $\frac{{{\overline{\Gamma }}_n}^0}{D}$ was obtained. The experimental values of the strength function indicate a maximum near $A=53\mathrm{}$. This is consistent with the prediction of the theory of Feshbach, Porter and Weisskopf for a square-well potential with $V_0=44\mathrm{}$ Mev, $\zeta =0.03\mathrm{}$ and $R=(1.26\mathrm{}{A}^{\frac{1}{3}}+0.7)\times {10}^{-13\mathrm{}}$ cm. The shape of the observed maximum is not in agreement with this simple theory, however, so a discussion is given which compares the present measurements with predictions based on more realistic models of the nucleus.

• Received 23 September 1957

DOI:https://doi.org/10.1103/PhysRev.111.288