  Detrimental beam dynamics effects limit performance of high intensity rapid
cycling synchrotrons (RCS) such as the 8 GeV proton Fermilab Booster. Here we
report the results of comprehensive experimental studies of various beam
intensity dependent effects in the Booster. In the first part, we report the
dependencies of the Booster beam intensity losses on the total number of
protons per pulse and on key operational parameters such as the machine tunes
and chromaticities. Then we cross-check two methods of the beam emittance
measurements (the multi-wires proportional chambers and the ionization profile
monitors). Finally we used the intensity dependent emittance growth effects to
analyze the ultimate performance of the machine in present configuration, with
the maximum space-charge tuneshift parameter Qsc of 0.6, and after its
injection energy is upgraded from 0.4 GeV to 0.8 GeV.
