The magpie project: Full system tests and preliminary plasma experiments

Results are presented from preliminary experiments with carbon, aluminium and CD2 fibre z-pinches at currents of up to 900kA. Rapid axial motion can be observed in optical streaks at velocities of up to 3×10⁵ms⁻¹. This motion can be correlated to high temperature bright regions observed using a four-frame 2ns gated soft X-ray camera. An explanation for this axial motion is offered in terms of the formation of a high temperature (T > 1keV) region which launches axial shock fronts into the much cooler background plasma. Towards peak current, a series of hard X-ray bursts indicate the formation of electron beams. Experiments in CD2 fibres give a mean neutron yield of 9×10⁸. The majority of these neutrons are generated during the period of the electron beam and are therefore not thought to be thermal in origin.