Professor Justin Wark: Publications

Investigation of femtosecond collisional ionization rates in a solid-density aluminium plasma

Nature Communications Springer Nature 6:1 (2015) 6397

Authors:

SM Vinko, O Ciricosta, TR Preston, DS Rackstraw, CRD Brown, T Burian, J Chalupský, BI Cho, H-K Chung, K Engelhorn, RW Falcone, R Fiokovinini, V Hájková, PA Heimann, L Juha, HJ Lee, RW Lee, M Messerschmidt, B Nagler, W Schlotter, JJ Turner, L Vysin, U Zastrau, JS Wark

The creation of large-volume, gradient-free warm dense matter with an x-ray free-electron laser

Physics of Plasmas AIP Publishing 22:3 (2015) 030703

Authors:

A Lévy, P Audebert, R Shepherd, J Dunn, M Cammarata, O Ciricosta, F Deneuville, F Dorchies, M Fajardo, C Fourment, D Fritz, J Fuchs, J Gaudin, M Gauthier, A Graf, HJ Lee, H Lemke, B Nagler, J Park, O Peyrusse, AB Steel, SM Vinko, JS Wark, GO Williams, D Zhu, RW Lee

Simulations of x-ray diffraction from uniaxially-compressed highly-textured polycrystalline targets

(2015)

Authors:

David McGonegle, Despina Milathianaki, Bruce A Remington, Justin S Wark, Andrew Higginbotham

Saturable Absorption of an X-Ray Free-Electron-Laser Heated Solid-Density Aluminum Plasma

Physical Review Letters American Physical Society (APS) 114:1 (2015) 015003

Authors:

DS Rackstraw, O Ciricosta, SM Vinko, B Barbrel, T Burian, J Chalupský, BI Cho, H-K Chung, GL Dakovski, K Engelhorn, V Hájková, P Heimann, M Holmes, L Juha, J Krzywinski, RW Lee, S Toleikis, JJ Turner, U Zastrau, JS Wark

The creation of large-volume, gradient-free warm dense matter with an x-ray free-electron laser

Physics of Plasmas 22:3 (2015)

Authors:

Abstract:

The efficiency and uniformity of heating induced by hard x-ray free-electron laser pulse is investigated for 0.5 μm silver foils using the X-ray Pump Probe instrument at the Linac Coherent Light Source facility. Intense 8.9 keV x-ray pulses of 60fs duration deposit energy predominantly via inner-shell ionization to create a non-equilibrium Ag solid density plasma. The x-ray pulses are focused to 14 × 17 μm2 by means of beryllium lenses and by varying the total beam energy, the energy deposition is varied over a range of irradiances from 4.4 to 6.5 × 1015 ∼ W/cm2. Two time-and-space resolved interferometers simultaneously probed the expansion of the front and rear sample surfaces and find evidence of a nearly symmetric expansion pointing to the uniformity of energy deposition over the full target thickness. The experimental results are compared with two different hydrodynamic simulations of the sample expansion. The agreement between experimental and theoretical results yields an estimate of the temperature evolution as a function of x-ray irradiance that varies from 8 to 10 eV for the x-ray irradiances studied.

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