An experimental investigation of collisions between supersonic plasma jets with metal foils and head-on collisions of two jets will be presented. The jets are produced by ablation of thin aluminium foils driven by 1.4MA, 250ns current pulse in a radial foil Z-pinch configuration. The jets propagate with velocity of 50-100km/s, showing a high degree of collimation (opening angle 2 [degrees] to 5 [degrees]) and are radiatively cooled (cooling time << hydrodynamic times). Collisions of the jets with foils, as well as inter-jet collisions, create a system of strong shocks both in the central dense part of the jet and in the lower density halo plasma which surrounds the jet and moves with the same speed. The formed shock features are sustained for 300ns, and are diagnosed with laser interferometry, optical and XUV imaging, and Thomson scattering diagnostics. Interpretation of the results indicates that dynamically significant magnetic fields are present in the system, balancing the ram pressure of the flow and supporting extended stationary shock structures. The results are relevant to the studies of astrophysical phenomena in the laboratory, in particular internal shocks in jets from young stars, accretion shocks, and for the understanding of magnetised high energy density plasma flows.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:624075 |
| Date | January 2013 |
| Creators | Pickworth, Louisa Alyce |
| Contributors | Lebedev, Sergey ; Bland, Simon |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/15670 |
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