  This paper has the purpose to study the rate capability of the Resistive
Plate Chamber, RPC, starting from the basic physics of this detector. The
effect of different working parameters determining the rate capability is
analysed in detail, in order to optimize a new family of RPCs for applications
to heavy irradiation environments and in particular to the LHC phase 2. A
special emphasis is given to the improvement achievable by minimizing the
avalanche charge delivered in the gas. The paper shows experimental results of
Cosmic Ray tests, performed to study the avalanche features for different gas
gap sizes, with particular attention to the overall delivered charge. For this
purpose, the paper studies, in parallel to the prompt electronic signal, also
the ionic signal which gives the main contribution to the delivered charge.
Whenever possible the test results are interpreted on the base of the RPC
detector physics and are intended to extend and reinforce our physical
understanding of this detector.
