The plasma parameters of the radio frequency (RF) negative ion source directly affect the density of negative ion and the uniformity of the plasma in the extraction zone. In order to understand the behavioral characteristics of the plasma inside the RF negative ion source, a set of Langmuir probe system (plate probe and cylindrical probe) was developed and tested on the RF ion source test...
Steady-state operation mode of a fusion neutron source (FNS) will require plasma heating and maintaining the current in it by fast atoms beam injecting. The DEMO-FNS project [1] assumes the use of six injectors providing additional heating power up to 30 MW at an atomic energy of 500 keV. As a prototype for the DEMO-FNS injector, an injector developed in detail for the ITER project can be...
BTR code, which is generally used for NBI beamlines design and optimizations, is applied to calculate the injected beam stopping in plasma, beam deposition and shine-through power in a fusion neutron source DEMO-FNS (R = 3.2m, a = 1m, k = 2, B = 5T, Eb = 500keV, PNBI ≈ 30MW). Beam-plasma model calculates the detailed beam spatial and angular distributions with account of injector and tokamak...
BTR code has been used for many years in the design and performance optimization of ITER HNB/DNB components and other NBI systems based on negative or positive ion sources. BTR beam formation and transmission along the beam line is simulated by a simple and comprehensive 6D beam model, which accounts for beam transport losses and power deposition on the injector surfaces. Beam particles tracks...
The gas pressure during plasma discharge affects the density and temperature of its electrons, which is essential to realize the steady-state operation of the radio frequency negative hydrogen ion source used in the nuclear fusion auxiliary heating experimental device.In order to maintain the density and uniformity of the plasma and improve the operating efficiency of the ion source.It is...
Neutral beam injectors inject multi megawatt neutral beams, several tens of amperes and energies from few 100 kV to MV, into the tokamak for heating and diagnostic purposes. The neutral beams are produced through the route of neutralisation of ion beams. The ion beams of machines like ITER shall use large area RF based negative ion sources, for plasma production, coupled to multi grid (3-7),...
A negative ion beam source of 200 keV / 0.5 A has been under development at National Fusion Research Institute (NFRI). Recently, a Cs dispenser was equipped to feed the Cs to enhance the source performance. To see the Cs seeding effect, preliminary short-pulse beam extraction experiments were carried out with 50 keV accelerator prior to the installation of 200 keV accelerator. It was confirmed...
A prototype radio frequency (RF) negative hydrogen ion source is under developing in the national fusion research institute (NFRI) in pursuing of the negative ion beam extraction of 200 keV, 0.5 A. The machine has extracted negative hydrogen ion beam since 2018, and recently two major upgrades have been implemented. The first upgrade is in the inductively coupled plasma (ICP) source. The ICP...
Collisional radiative (CR) models are useful to analyze the dynamic process of excited states and are in favor of optical emission spectroscopy (OES) in negative hydrogen ion source plasma. In this paper, a CR model of atomic hydrogen containing excitation of H, dissociative excitation by H2 and dissociative recombination by H2+ is developed. The above three channels account for the main...
Mechanism of the meniscus formation in negative ion sources for fusion has not been clarified yet since negative charges in the plasmas consist of multiple components, electron and negative ion, and a magnetic field in the vicinity of extraction holes has 3D complicated topology. In our previous study, correlation between the negative ion beam optics and plasma parameters was...
