The EPS Plasma Physics Division took the opportunity of its annual conference to reward researchers who have achieved outstanding scientific or technological results, thus reinforcing excellence in science.
The 2014 Hannes Alfvén Prize is awarded to Patrick Mora (Centre de Physique Théorique, Palaiseau, France) “for decisive results in the field of laser-produced plasma physics, in particular for illuminating descriptions of laser light absorption in plasmas, electron heat transport in steep temperature gradients and plasma expansion dynamics into vacuum”.
The first remarkable result of Patrick Mora is a theoretical model, now included in all the major textbooks, which couples laser light absorption and energy transport to plasma hydrodynamics. With his colleague Jean-François Luciani, he then proposed a nonlinear and nonlocal theory of electron heat transport which enables interpretation of experimental results showing a strong departure from the classical Spitzer and Härm formalism, thus inspiring a variety of models now currently used for laser or x‑ray created plasmas, especially in the context of inertial confinement fusion. Later, Patrick Mora drew, with Tom Antonsen (USA) a model for the propagation of a short laser pulse in under-dense plasmas, exhibiting its self-focusing character and its tendency to develop Raman‑like instabilities. The numerical code he elaborated, named WAKE, is proved to be more efficient than usual Particle-in-Cell codes in numerous experimental situations and is now widely used. In particular it enabled the first simulation of complete cavitation of electron density in what was later named the “bubble regime”, and shown to play a crucial role in relativistic quasi-monoenergetic electron beam acceleration. Finally his recent work on plasma expansion into vacuum is possibly his most important work as it gives a complete understanding of the flow dynamics, elucidating for instance the structure of the ion front and predicting the maximum ion velocity. This model was used to sustain a lot of recent experimental results on ion acceleration obtained in European laboratories.
The 2014 Plasma Physics Innovation Prize of the European Physical Society is awarded to Christoph Hollenstein (Centre de Recherches en Physique des Plasmas, Ecole Polytechnique de Lausanne, Switzerland) “for instrumental contributions to the field of Plasma Processes in Industry and for his strong impact in spin-off activities of fusion R&D”.
Among the various topics tackled by Christoph Hollenstein, one can first mention the development of a plasma process for thin film deposition using the plasma torch and, more significantly, all the work done on radio-frequency plasma reactors for large area deposition of amorphous or microcrystalline silicon for solar cell or flat display applications. As an additional outcome, he also contributed to the fundamental understanding of powder formation in reactive plasmas used for deposition of many important industrial coatings. He moreover studied the plasma chemistry of silicon-oxide deposition as barrier coating for packaging applications. More recently, a method was investigated to modify the functional and decorative properties – for instance the colour – of a substrate under reactive plasma conditions, with potential applications in the watch industry. Electrical discharge machining was investigated as well, with a systematic study on the eroding spark physics performed thanks to a set of plasma diagnostics, including spectroscopic and imaging tools, which demonstrated that the spark is a cold and dense, weakly non-ideal, plasma, thus improving the understanding of the fundamental mechanisms underlying the industrial process. Christoph Hollenstein and his colleagues have also uncovered the physics behind the formation of plasmoids in radio-frequency plasma reactors, which exhibit a funnel-like behaviour, and they proposed strategies to prevent damage induced by them. An additional experimental approach is currently used to explore arcing in spacecraft and spacecraft equipment, with special attention paid to arc ignition, propagation. Such studies lead to the development of safer electrical equipment. All these great developments and inventions were, and are, made in close collaboration with European industrial partners.
The 2014 EPS Plasma Physics Division PhD Research Award has been judged by an external committee, comprising Francesco Pegoraro (Italy), Miklos Porkolab (USA), Karl-Heinz Spatschek (Germany) and Elisabeth Rachlew (Sweden), who examined all the candidatures in a process managed by Elisabeth Wolfrum representing the EPS Plasma Physics Division. Based on their conclusions, this year’s award goes to Edmund Highcock (Oxford University, United-Kingdom) for his thesis entitled “The zero turbulence manifold of fusion plasmas”.