Antineutron physics at BNL and beyond

The history of antineutron counter experiments below 1 GeV/c is rather short. Several measurements of the charge exchange total and differential cross-sections have been reported. In addition there have been a few low statistics attempts to measure the (anti np transmission and annihilation cross-sections. In 1981 at BNL, AGS Experiment 767 was proposed to simultaneously measure both the annihilation and the transmission cross-sections for anti np). The data were taken during the winter and spring of 1984 and very preliminary results were reported at Durham in July 1984. The results presented here represent a significantly more complete data analysis but some sources of systematic error are still under investigation, and as such only relative cross-sections will be quoted which should still be regarded as preliminary to some degree