The Full-Size Source and Injector Prototypes for ITER Neutral Beams

Caesium influence on plasma parameters and source performance during conditioning of the prototype ITER neutral beam injector negative ion source

Systematic Langmuir probe measurements were performed during the caesium (Cs) conditioning of the IPP prototype negative hydrogen ion source. Conditioning consists of slowly injecting caesium into the source in order to increase the extracted negative ion current and minimize the co-extraced electrons. This process usually takes several days. Measurements were taken near the plasma grid where t...

Negative Ion Based Heating and Diagnostic Neutral Beams for ITER

To meet the requirements of the four operating and one start-up scenarios foreseen in the International Tokamak Experimental Reactor (ITER) a flexible heating mix will be required, which has to include a reliable contribution from neutral beams. The current baseline of ITER foresees 2 Heating Neutral Beam (HNB) systems based on negative ion technology, each operating at 1 MeV 40 A D ions, and e...

Active Spectroscopic Diagnostics for Iter Utilizing Neutral Beams

Optimization of the accelerators for the ITER Neutral Beam Injector project

A joint Japan-EU R&D activity is in progress to optimize the accelerator for the ITER NBI. The accelerator baseline design is based on a five grids system which can be adapted to operate with three grids for initial operations at low voltage (500 kV). Moreover, in order to speed up the test of the NBI system at the Test Facility, a negative ion source with extraction voltage up to 100kV will be...

Modeling of the negative ion extraction from a hydrogen plasma source. Application to ITER Neutral Beam Injector

The development of a high performance negative ion (NI) source constitutes a crucial step in the construction of Neutral Beam Injector of the future fusion reactor ITER. NI source should deliver 60 A of H (or 40 A D), which is a technical and scientific challenge, and requires a deep understanding of the underlying physics of the source including the role of the magnetic filter. The present kno...