ELECTRON CLOUD OBSERVATIONS AND CURES IN RHIC

Since 2081 MIC has experienced electron cloud effects, which have limited the beam intensity. These include dynamic pressure rises - including pressure instabilities, tune shifts: electrons, a reduction of the stability threshold for bunches crossing the transition energy, and possibly slow emittance growth. We summarize the main observations in operation and dedicated experiments, as well as countermeasures including baking, NEG coated warm beam pipes, solenoids, bunch patterns, anti-grazing rings, pre-pumped cold beam pipes, and scrubbing.