Quark number susceptibilities approach their ideal gas limit at sufficiently
high temperatures. As in the case of other thermodynamic quantities, this limit
itself is altered substantially on lattices with small temporal extent, N_t =
4-8, making it thus difficult to check the validity of perturbation theory.
Unlike other observables, improving susceptibilities or number densities is
subject to constraints of current conservation and absence of chemical
potential dependent divergences. We construct such an improved number density
and susceptibility for staggered fermions and show that they approximate the
continuum ideal gas limit better on small temporal lattices.Comment: Lattice2002(nonzerot), 3 pages, 3 figure