Publication

Helicon wave-generated plasmas for negative ion beams for fusion

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello, Gennady Plyushchev, Claudio Marini
2017
Conference Papers

Abstract

In the next generation of fusion reactors, such as DEMO, neutral beam injectors (NBIs) of high energy (0.8-1 MeV) deuterium atom swith high wall-plug efficiency (>50%) will be required to reach burning plasma conditions and to provide a significant amount of current drive.The present NBI system for DEMO assumes that 50 MW is delivered to the plasma by 3 NBIs. In the Siphore NBI concept, negative deuterium ions are extracted from a long, thin ion source 3 m high and 15 cm wide, accelerated and subsequently photo-neutralized. This requires the development of a new generation of negative ion sources. At the Swiss Plasma Center, a novel radio frequency helicon plasma source, based on a resonant network antenna source delivering up to 10 kW at 13.56 MHz, has been developed and is presently under study on the Resonant Antenna Ion Device (RAID). RAID is a linear device (1.9 m total length, 0.4 m diameter) and is equipped with an extensive set of diagnostics for full plasma characterization. In this work, the principles of operation of resonant antennas as helicon sources areintroduced. Wepresent absolute spectroscopy, Langmuir probe, and interferometry measurements on helicon plasmas. We characterize the performanceof the source in terms of hydrogen/deuterium dissociation and negative ion production as a function of the input power. Furthermore, first results with the helicon birdcage antenna installed on the Cybele negative ion source at CEA-IRFM arepresented, as a first step towards the validation of the Siphoreconcept.

Official source

https://infoscience.epfl.ch/entities/publication/838ca226-4a0a-4dd3-93bb-5108026cb3db

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello, Gennady Plyushchev, Claudio Marini
2017
Conference Papers

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/838ca226-4a0a-4dd3-93bb-5108026cb3db

Related concepts (31)

Neutral-beam injection

Neutral-beam injection (NBI) is one method used to heat plasma inside a fusion device consisting in a beam of high-energy neutral particles that can enter the magnetic confinement field. When these neutral particles are ionized by collision with the plasma particles, they are kept in the plasma by the confining magnetic field and can transfer most of their energy by further collisions with the plasma. By tangential injection in the torus, neutral beams also provide momentum to the plasma and current drive, one essential feature for long pulses of burning plasmas.

Ion source

An ion source is a device that creates atomic and molecular ions. Ion sources are used to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines. Electron ionization Electron ionization is widely used in mass spectrometry, particularly for organic molecules. The gas phase reaction producing electron ionization is M{} + e^- -> M^{+\bullet}{} + 2e^- where M is the atom or molecule being ionized, e^- is the electron, and M^{+\bullet} is the resulting ion.

Plasma propulsion engine

A plasma propulsion engine is a type of electric propulsion that generates thrust from a quasi-neutral plasma. This is in contrast with ion thruster engines, which generate thrust through extracting an ion current from the plasma source, which is then accelerated to high velocities using grids/anodes. These exist in many forms (see electric propulsion). However, in the scientific literature, the term "plasma thruster" sometimes encompasses thrusters usually designated as "ion engines".

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