A series of experimental measurements of fast ions generated in a tungsten conical wire array are presented. The ions are detected using a set of negatively biased Faraday cups located on axis above the array at distances between 10 and 67 cm. Significant differences in the signals from the probes are found on varying the background atmospheric pressure between 10(-2) and 10(-5) Torr. At 10(-5) Torr, a pulse of ions moving at 10(6) m/s is collected by the cups. In contrast, at intermediate (10(-4) Torr) and high (10(-2) Torr) pressures, both electrons and ions are detected with a velocity of order 10(6) m/s. The differences with pressure are ascribed to the ionization of the background gas by the tungsten ions. Time-of-flight measurements show the emission of fast ions during the ablation phase of wire array dynamics. Comparing the temporal behavior of the ions and their velocity of propagation with the dynamics observed using UltraViolet / eXtreme UltraViolet imaging allows us to conclude that the ions and the dense plasma jet are different phenomena. Moreover, the application of a transverse electric field establishes the presence of massive ions in the outflow, suggesting also the presence of MeV tungsten ions with ionization of five or less. The observation of a fast particle outflow from a conical wire array and a possible ejection mechanism is discussed. Published by AIP Publishing.