The 2018 APS/EPS Landau-Spitzer Award
The 2018 APS/EPS Landau-Spitzer Award for the development of “A novel and very efficient method to heat fusion plasmas using electromagnetic waves” awarded to
- Yevgen Kazakov, Jef Ongena, Plasma Physics Lab, Royal Military Academy, Brussels, Belgium
- John Wright, Steven Wukitch, Plasma Science and Fusion Centre, MIT, Boston, USA
For the development of a new and highly efficient scenario for heating of fusion plasmas using Ion Cyclotron Resonant Heating (ICRH), the joint team consisting of Yevgen Kazakov and Jef Ongena, from the Laboratory for Plasma Physics of the Royal Military Academy (Brussels, Belgium) and John Wright and Steven Wuktich from the Plasma Science and Fusion Centre at MIT (Boston, USA) was awarded last July the prestigious Landau-Spitzer Award “for experimental verification, through collaborative experiments, of a novel and highly efficient ion cyclotron resonance heating scenario for plasma heating and generation of energetic ions in magnetic fusion devices”. The award recognizes an individual or group of researchers for outstanding theoretical, experimental or technical contributions in plasma physics, and for advancing the collaboration and unity between the European Union (EU) and the United States of America (USA) by joint research, or research that advances knowledge which benefits the EU and USA communities in a unique way. The Award Ceremony took place on the 9th November, at the occasion of the 60th Conference of the Division of Plasma Physics of the American Physical Society (APS-DPP), which took place this year in Portland, Oregon.
For this newly developed, so-called “three-ion ICRH heating scenario”, a plasma consisting of two main ions (e.g. H and D) is needed plus a third ion (e.g. 3He) or a fast main ion as minority ions. The main idea behind this new scenario is that by cleverly arranging the plasma conditions, all the radiofrequency power injected into the plasma by the RF antennas in the edge is absorbed by the minority particles. The efficiency of the theoretically derived new ICRH scenario was experimentally demonstrated by accelerating a small amount of 3He ions in a plasma containing 80%H and 20%D on the largest tokamak in the world JET (Joint European Torus, Culham, UK) and the high magnetic field tokamak Alcator C-Mod (MIT, Boston, USA). The presence of 3He ions with MeV-range energies was confirmed using several fast-ion diagnostics on both devices. Effective plasma heating was observed as a result of the slowing-down of the fast 3He ions. The efficiency of the method was also recently shown on a third fusion device, the tokamak ASDEX Upgrade in Garching, Germany. Last, but not least, the physical mechanism that underpins this novel heating technique also provides a simple and quantitative explanation for a long-standing mystery: the existence of solar flares with a high 3He abundance. The common work resulted in a joint publication in the Nature Physics issue of October 2017.
Developing heating scenarios for efficient ion heating of multi-ion plasmas is rather important. The example ‘by excellence’ of such mixed plasmas are the D-T plasmas in a future fusion reactor. But the three-ion ICRH scenarios provide further flexibility by making beneficial use of the so-called intrinsic impurity ions that are anyhow present in the fusion plasma. Depositing the RF power into intrinsic 9Be ions, for instance, offers the additional advantage of an increased heating of D and T ions, because of the heavier mass of 9Be compared to H, D or He isotopes, used traditionally in ICRH heating. Acceleration of fast D or T ions from the Neutral Beam Injectors (NBI) to higher energies in synergetic ICRH+NBI three-ion heating scenarios is also possible, and this in turn offers potential to contribute to boosting the fusion performance and maximizing the steady-state Q-value in future D-T experiments on JET. These examples illustrate the large range of applications of the new ICRH scenario and its potential to contribute to the development of fusion energy.
