Speaker
Peta Suzanne Foster
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.2011.pdf
Radiography of gas-gun impact experiments using an X-pinch
P.S. Foster1, G. C. Burdiak1, H. Doyle1, S.N. Bland2, T. Ringrose1, J.W. Skidmore1, N.
Hawker1
1
First Light Fusion Ltd, Yarnton, Oxfordshire, OX5 1QU
2
Institute of Shock Physics, Imperial College London, London, SW7 2AZ, UK
A broadband point-projection x-ray backlighter has been commissioned at First Light Fusion
Ltd for radiographing impact experiments driven by a two-stage light gas gun. X-ray energies
of 10 - 20 keV are produced by a miniature electron beam diode which forms during the
explosion of a tungsten X-pinch. The X-pinch source emits a 20 ns x-ray pulse from a 200 -
300 um diameter spot, and the imaging setup achieves a spatial resolution of 50 - 100 um at a
magnification of 2.3, over a 29 mm field of view.
The X-pinch load is made from 4 x 7.5 um tungsten wires, which are driven by the 70 kA, 70
ns rise-time current pulse from a high impedance pulsed-power machine. A 4 Ohm
water-filled pulse-forming line drives a high inductance magnetically insulated transmission
line, which delivers the current to the X-pinch load within the gas-gun experimental
chamber.
The backlighter is used to image density structures within cm-scale plastic targets during
impact with a 6 km/s projectile. Here, we present radiographs from preliminary experiments
together with details of the experimental setup and characterisation of the x-ray source. We
demonstrate the ability of the diagnostic to image forward and reverse shocks, release waves,
projectile deformation and jet density profiles.
