Perturbative transport studies in the reversed-field pinch

In this paper we present the results of transient transport experiments in a reversed-field pinch device. Measurements have been made in the Madison Symmetric Torus experiment using a novel soft x-ray diagnostic. Spontaneous transient transport events are observed in enhanced confinement shots obtained using the pulsed parallel current drive technique, as a consequence of bursts of magnetic fluctuations triggered by an edge resonant m = 0 instability. The perturbed electron heat diffusivity, chi(e), is estimated through a numerical transient heat transport model, and the values thus obtained are compared with those measured in similar unperturbed enhanced confinement and standard plasmas using the power balance technique.