Speaker
Daniel Russell
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.4003.pdf
The effect of advected magnetic fields in jet propagation experiments
D. R. Russell1, S. V. Lebedev1, G. C. Burdiak2, J. W. D. Halliday1, J. D. Hare1, L. G. Suttle1,
F. Suzuki-Vidal1, E. Tubman1, T. A. Clayson1
1
Imperial College London, UK
2
First Light Fusion Ltd, Oxford, UK
Astrophysical jets are a common feature during star formation. It is believed that magnetic
fields play a key role in the formation of these jets, however the interaction of the jet with the
ambient medium far from the source is dominated by purely hydrodynamical processes [1].
Appropriately scaled laboratory experiments, in which the amount of advected magnetic field
can be controlled, can aid our understanding of the observed complex structure of these jets.
The use of pulsed power-driven ablation of conical wire arrays [2] has allowed the production
of supersonic, radiatively cooled jets scalable to astrophysical systems. In some of these
experiments, the advected magnetic field was dynamically significant, which was most evident
in the interaction of the jet with an ambient medium [3]. To enable the full range of jet dynamics
to be studied, it is desirable to be able to modify the jet magnetisation within the same
experimental setup.
Here we present experimental results from a new conical wire array jet-launching platform, in
which the magnetic field advected by the jet is expected to be significantly reduced in
comparison with previous experiments. This is achieved by preconditioning the wires with a
pre-pulse current [4], allowing the formation of a supersonic jet driven by a fast plasma
implosion. These experiments are carried out on the Magpie (~1 MA, 250ns) pulsed power
generator, using a suite of high temporal and spatial resolution diagnostics. Faraday rotation
polarimetry, Thomson scattering and laser interferometry, allow direct measurement of the
magnetic field, electron and ion temperatures, flow velocities and electron density distributions.
This work was supported in part by First Light Fusion Ltd, the Engineering and Physical
Sciences Research Council (EPSRC) Grant No. EP/N013379/1, and by the NNSA under DOE
agreements DE-F03-02NA00057, DE-SC-0001063 and DE-NA-0003764
[1] P. Hartigan et al (2001). ApJ, 559, L157
[2] D. J. Ampleford et al (2008). PRL, 100, 035001
[3] D. J. Ampleford et al (2005). Astrophys. Space Sci, 298 (1–2), 241
[4] G. C. Burdiak et al (2015). PoP, 22, 112710
