  Charged particle production has been studied in neutral current deep
inelastic ep scattering with the ZEUS detector at HERA using an integrated
luminosity of 0.44 fb^-1. Distributions of scaled momenta in the Breit frame
are presented for particles in the current fragmentation region. The evolution
of these spectra with the photon virtuality, Q^2, is described in the kinematic
region 10<Q^2<41000 GeV^2. Next-to-leading-order and modified
leading-log-approximation QCD calculations as well as predictions from Monte
Carlo models are compared to the data. The results are also compared to e+e-
annihilation data. The dependences of the pseudorapidity distribution of the
particles on Q^2 and on the energy in the \gamma p system, W, are presented and
interpreted in the context of the hypothesis of limiting fragmentation.
