In the Ba (B) over bar ar experiment at SLAG a novel, compact, ring imaging
detector was developed to accomplish the challenging task of identifying p
articles over a momentum range up to similar to4.3 GeV/c. The principles an
d operation are described. It has been in operation in Ba (B) over bar ar d
uring the first year of data taking. Some of this data are presented to sho
w how well it performs. Plans and future potential for this device are also
outlined.