Pb(n,n'x) at 65 MeV and the isospin structure of the giant quadrupole resonance region.

The first Pb(n,n'x) data (at 65 MeV) are compared to earlier (61-- MeV) (p,p'x) data. The isovector sensitivity of these nucleon probes is used to determine M/sub n//M/sub p/approx. =N/Z = 1.54 for the giant quadrupole resonance (GQR). This result is consistent with other direct GQR measurements, 2/sub 1//sup +/ data connected through core polarization, and several microscopic random-phase approximation calculations, but in disagreement with a ..pi../sup -//..pi../sup +/ study which gives M/sub n//M/sub p/ = 3.8 +- 1.2. .AE