Current conversion in the sliding charge density wave state of NbSe3

High spatial resolution (30-100 mu m) X-ray measurements of the satellite p ositional shift q have been carried out in the upper charge-density-wave st ate of NbSe3. We determined the spatial distribution of the CDW plastic def ormations between electrodes under applied currents. With direct current we observe a steep exponential decrease of q with position x along the sample near the contacts followed by a linear dependence in the central part of t he sample. This second regime is attributed to transverse pinning of the CD W dislocations while the first is dominated by phase slip processes. The ob served differences between data from direct current and pulsed current meas urements indicate a significant, strongly spatially dependent relaxational behaviour of the CDW deformations.