Publication Date:
2019
abstract:
To reach fusion conditions and control plasma configuration in ITER, a suitable combination of additional
heating and current drive systems is necessary. Among them, two Neutral Beam Injectors (NBI) will provide
33 MW hydrogen/deuterium particles electrostatically accelerated to 1 MeV; efficient gas-cell neutralisation at
such beam energy requires negative ions, obtained by caesium-catalysed surface conversion of atoms inside the
ion source. As ITER NBI requirements have never been simultaneously attained, a Neutral Beam Test Facility
(NBTF) was set up at Consorzio RFX (Italy), including two experiments. MITICA is the full-scale NBI prototype
with 1 MeV particle energy. SPIDER, with 100 keV particle energy, aims at testing and optimising the full-scale
ion source: extracted beam uniformity, negative ion current density (for one hour) and beam optics (beam
divergence < 7 mrad; beam aiming direction within 2 mrad). This paper outlines the worldwide effort towards
the ITER NBI realisation: the main results of the ELISE facility (IPP-Garching, Germany), equipped with a halfsize source, are described along with the status of MITICA; specific issues are investigated by small specific
facilities and by joint experiments at QST and NIFS (Japan). The SPIDER experiment, just come into operation,
will profit from strong modelling activities, to simulate and interpret experimental scenarios, and from advanced
diagnostic instruments, providing thorough plasma and beam characterisation. Finally, the results of the first
experiments in SPIDER are presented, aimed at a preliminary source plasma characterisation by plasma light
detectors and plasma spectroscopy.
heating and current drive systems is necessary. Among them, two Neutral Beam Injectors (NBI) will provide
33 MW hydrogen/deuterium particles electrostatically accelerated to 1 MeV; efficient gas-cell neutralisation at
such beam energy requires negative ions, obtained by caesium-catalysed surface conversion of atoms inside the
ion source. As ITER NBI requirements have never been simultaneously attained, a Neutral Beam Test Facility
(NBTF) was set up at Consorzio RFX (Italy), including two experiments. MITICA is the full-scale NBI prototype
with 1 MeV particle energy. SPIDER, with 100 keV particle energy, aims at testing and optimising the full-scale
ion source: extracted beam uniformity, negative ion current density (for one hour) and beam optics (beam
divergence < 7 mrad; beam aiming direction within 2 mrad). This paper outlines the worldwide effort towards
the ITER NBI realisation: the main results of the ELISE facility (IPP-Garching, Germany), equipped with a halfsize source, are described along with the status of MITICA; specific issues are investigated by small specific
facilities and by joint experiments at QST and NIFS (Japan). The SPIDER experiment, just come into operation,
will profit from strong modelling activities, to simulate and interpret experimental scenarios, and from advanced
diagnostic instruments, providing thorough plasma and beam characterisation. Finally, the results of the first
experiments in SPIDER are presented, aimed at a preliminary source plasma characterisation by plasma light
detectors and plasma spectroscopy.
Iris type:
01.01 Articolo in rivista
Keywords:
Neutral beam injectors; Negative ion beam; Negative ion source
List of contributors:
Pomaro, Nicola; Antoni, Vanni; DE LORENZI, Antonio; Taliercio, Cesare; Serianni, Gianluigi; Grando, Luca; Spolaore, Monica; Recchia, Mauro; Agostinetti, Piero; Agostini, Matteo; Brombin, Matteo; DALLA PALMA, Mauro; Luchetta, ADRIANO FRANCESCO; Piovan, Roberto; Toigo, Vanni; Zaccaria, Pierluigi; Gaio, Elena; Marchiori, Giuseppe; Manduchi, Gabriele; Pasqualotto, Roberto
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