Cluster PEACE observations of electron pressure tensor divergence in the magnetotail

Cluster crossed the magnetotail neutral sheet on four occasions between 16: 38 and 16: 43 UT on 08/17/2003. The four-spacecraft capabilities of Cluster are used to determine spatial gradients from the magnetic field vectors and, for the first time, full electron pressure tensors. We find that the contribution to the electric field from the Hall term (max of similar to 6 mV/m) pointed towards the neutral sheet, whereas that from the electron pressure divergence ( max of similar to 1 mV/m) pointed away from the neutral sheet. The electric field contributions in this direction were closely anti-correlated. During this period Clusters 1 and 4 were sometimes above and below the neutral sheet respectively. This allowed the simultaneous observation of magnetic fields that are interpreted as two quadrants of the Hall magnetic field system. An associated field-aligned current system was detected using the curlometer and moments of the particle distributions.