Preparation of the ELISE test facility for long-pulse extraction of negative ion beams

Nocentini, R.; Fantz, U.; Froeschle, M.; Heinemann, B.; Kraus, Werner; Riedl, R.; Wuenderlich, Dirk

doi:10.1016/j.fusengdes.2017.05.082

Cited by 5 publications

(1 citation statement)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, one has to note that an isotope effect like the change in Cs recycling may appear differently between an arc discharge source and an RF discharge source. Some maintenance requirements more complicated than the ones discussed in the past by Hemsworth et al [165] may be required for the neutral beam heating system. The RF source was chosen since 2007 as the reference source for ITER, which solves the Cs problem of enhanced sputtering yield of filaments by deuterium.…”

Section: Research To Meet Requirements For Iter Nbimentioning

confidence: 99%

Negative ion source operation with deuterium

Bacal

Wada

2020

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

When the working gas of a negative ion source is changed from hydrogen to its isotope, deuterium, an ‘isotope effect’ is observed; namely, several plasma characteristics such as the electron energy distribution, the atomic fraction and the spectra of rovibrationally excited molecules change. The understanding of the effect becomes more important, as research and development aiming at ITER power level operation is being challenged with feeding deuterium to the ion sources. As a historical review of the effort to develop hydrogen/deuterium negative ion sources, several types of negative ion sources designed for the neutral beam plasma heating are described: double charge exchange sources, volume sources and surface-plasma sources. The early results with volume sources operated with and without cesium are introduced. The characteristics of the source charged with deuterium are compared to those of the source charged with hydrogen. The isotope effect did not appear pronounced as the negative ion density was measured in a small source but became more pronounced when the plasma source size was enlarged and the discharge power density was increased to higher values. Surface plasma sources were optimized for deuterium operation but could not achieve the same performance as a source operated with hydrogen at the same power and pressure. The lower velocity of negative deuterium ions leaving the low work function surface seemed to limit the production efficiency. Fundamental processes causing these differences in negative ion source operation are summarized. After explaining the current status of negative ion source research and development, the acquired knowledge is utilized to the development of large negative ion sources for nuclear fusion research and to the development of compact negative ion sources for neutron source applications.

show abstract

Section: Research To Meet Requirements For Iter Nbimentioning

confidence: 99%

Negative ion source operation with deuterium

Bacal

Wada

2020

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

show abstract

Surface Plasma Production of Negative Ions

Dudnikov

2023

Springer Series on Atomic, Optical, and Plasma Physics

View full text Add to dashboard Cite

Equivalent circuit and numerical analyses of an inductively coupled plasma torch with a tapped induction coil

et al. 2018

View full text Add to dashboard Cite

Equivalent circuit and numerical analyses of an Ar-N2 inductively coupled plasma (ICP) were conducted in order to clarify the effect of the induction coil with a grounded tap on the electrical characteristics of an ICP torch system. First, from the computational results, it was revealed that the load resistance of tank circuit for a free running radio-frequency (RF) oscillator can be reduced to about 25% with a center-tap of the induction coil grounded. Despite the asymmetric distributions of the electric fields in the inside of the ICP torch, this effect was found due to the equivalent resistance and inductance of ICP that were divided in approximately half into each part of the center-tapped induction coil. The reduction of the load resistance by a grounded tap was also observed in generation experiments of Ar-N2 ICPs using a vacuum tube oscillator for various N2 contents ranging from 6.3 % to 25.0 %. By providing a way to reduce the load resistance of the tank circuit, the induction coil with a grounded tap can be used to improve the impedance matching condition of ICP systems with the load resistances higher than the internal resistance of a free running RF oscillator.

show abstract

Preparation of the ELISE test facility for long-pulse extraction of negative ion beams

Cited by 5 publications

References 16 publications

Negative ion source operation with deuterium

Negative ion source operation with deuterium

Surface Plasma Production of Negative Ions

Equivalent circuit and numerical analyses of an inductively coupled plasma torch with a tapped induction coil

Contact Info

Product

Resources

About