The target fragment production cross sections have been measured for the reaction of 150 MeV/nucleon ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}$ with ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$. From these cross sections, the fragment isobaric yields were deduced. The resulting isobaric yield distribution is very similar to that observed for reactions in which limiting fragmentation is occurring (such as the reaction of 8 GeV ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ with ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$) and unlike that observed with projectiles of similar velocity. This apparent extreme example of total projectile kinetic energy scaling is compared to predictions of the intranuclear cascade model.

• Received 11 April 1988

DOI:https://doi.org/10.1103/PhysRevC.38.2094