One-dimensional ordering in coasting and bunched beams

The sudden reduction of momentum spread, and under certain conditions also of Schottky-noise power, that has been observed with electron-cooled coasting beams of highly charged ions at several storage rings, has been interpreted as the effect of a one-dimensional ordering of the beams. At CRYRING, first observations of a momentum-spread reduction have also been made with bunched beams. We discuss models of one-dimensional ordering and compare model predictions of Schottky-noise power, and in the case of bunched beams the bunch length, with experimental results from CRYRING.