Charged Particle Multiplicities from Cu+Cu, Au+Au and d+Au Collisions at RHIC

The charged particle multiplicity produced at RHIC will be presented as a function of collision energy, system size and geometry. The results will include d+Au, Au+Au and the recent Cu+Cu data. The data presented will utilize the unique, and nearly complete, solid angle coverage of the PHOBOS detector. With the data available, we will examine volume effects on the charged particle multiplicity to address global features of the particle production at RHIC energies. The data will be discussed in terms of collision geometry scaling of mid-rapidity yields and extended longitudinal scaling of the pseudo-rapidity density distributions.