Numerical study of atomic production rate in hydrogen negative ion sources with the effect of non-equilibrium electron energy distribution function

Shibata, T.; Kashiwagi, M.; Inoue, Takashi; Hatayama, A.; Hanada, M.

doi:10.1063/1.4824366

Cited by 23 publications

(21 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The detailed representations of the CR models for H and H 2 in non-equilibrium plasma (or EEDF) are shown in Ref. [4,5]. In the present model, Quasi-Steady State (QSS) assumption has been applied for excited molecules [6].…”

Section: -3mentioning

confidence: 99%

Numerical and experimental study of atomic transport and Balmer line intensity in Linac4 negative ion source

Shibata

Mattei

Nishida

et al. 2015

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

Section: -3mentioning

confidence: 99%

Numerical and experimental study of atomic transport and Balmer line intensity in Linac4 negative ion source

Shibata

Mattei

Nishida

et al. 2015

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

“…For example, such a kind of non-uniformity was observed in the N-NBI system [20] for the JAEA (Japan Atomic Energy Research Agency: * present QST: National Institute for Quantum and Radiological Science and Technology) JT-60U tokamak. The JT-60U tokamak is one of the largest magnetic fusion devices in the world and now is being upgraded to the JT-60SA with superconducting magnets for plasma confinement [24].A series of modeling studies [25][26][27][28][29][30][31] for such giant sources, more specifically, for the QST 10A source and JT-60SA H − source will be reviewed (section 2.3). The effect of the EEDFs on H − SP and the origin of H − beam non-uniformity will be discussed.…”

mentioning

confidence: 99%

Present status of numerical modeling of hydrogen negative ion source plasmas and its comparison with experiments: Japanese activities and their collaboration with experimental groups

et al. 2018

View full text Add to dashboard Cite

The present status of kinetic modeling of particle dynamics in hydrogen negative ion (H − ) source plasmas and their comparisons with experiments are reviewed and discussed with some new results. The main focus is placed on the following topics, which are important for the research and development of H − sources for intense and high-quality H − ion beams: (i) effects of non-equilibrium features of electron energy distribution function on volume and surface H − production, (ii) the origin of the spatial non-uniformity in giant multi-cusp arc-discharge H − sources, (iii) capacitive to inductive (E to H) mode transition in radio frequency-inductively coupled plasma H − sources and (iv) extraction physics of H − ions and beam optics, especially the present understanding of the meniscus formation in strongly electronegative plasmas (so-called ion-ion plasmas) and its effect on beam optics. For these topics, mainly Japanese modeling activities, and their domestic and international collaborations with experimental studies, are introduced with some examples showing how models have been improved and to what extent the modeling studies can presently contribute to improving the source performance. Close collaboration between experimental and modeling activities is indispensable for the validation/improvement of the modeling and its contribution to the source design/development. chamber wall (anode) and filaments (cathode). In the latter sources, the RF-electromagnetic field is used to generate and heat plasmas.In this review, we mainly focus on the modeling studies, especially the modeling study of H − source plasmas using kinetic approaches, such as the test particle Monte-Carlo model [14] and particle in cell (PIC) model [14,15], which has been reviewed in [16]. Here, we extend it with some new results. Close collaboration between the experimental and modeling study is very important as it can improve our basic understanding of source plasmas. Various examples of the model validation will be shown through comparisons with experiments and also how modeling studies contribute to the improvement of source performances.As for the multi-cusp arc-discharge source, we will first show a systematic study to help us understand the role of the EEDF on the H − VP in section 2.2. The study has been carried out for a compact multi-cusp arcdischarge source (SHI H − source: Sumitomo Heavy Industry H − source [17,18]) for medical application such as boron neutron capture therapy and the radioisotope production for molecular imaging technology.The SHI H − source is a typical tandem type H − source [19]. In such a tandem type volume sources, the plasma source volume is divided into two regions by the transverse magnetic field (the so-called magnetic filter filed: MF-field) to control the EEDFs and to promote the two step H − VP reactions explained above. Namely, the source volume consists of two regions: (1) the 'driver region' where the electron energy is high and the EV process is promoted, and (2) the 'extraction region' where the electr...

show abstract

“…In addition to the ground‐state atom modelled above, we solve a system of simultaneous rate equations for the population density of excited atoms with the quasi‐steady‐state collisional–radiative model (QSS‐CR) developed in refs . The QSS‐CR model can calculate H α intensity as well, and it enables our 0D model to simulate the experimental method for controlling the core plasma density in the QUEST tokamak.…”

Section: Model Equations For the Particle Balancementioning

confidence: 99%

Modelling of plasma and its wall interaction for long‐term tokamak operation

Okamoto

Tatsumi

Abe

et al. 2018

Contributions to Plasma Physics

Self Cite

View full text Add to dashboard Cite

Metal plasma‐facing materials (PFMs) are expected to be candidates for future fusion power plants from the view point of tritium retention. The purpose of this study is to develop a model including a long timescale plasma interaction with metal PFMs. As a first step, we have developed a simple zero‐dimensional (0D) model, which consists of particle balance equations for the following three different particle species: (a) hydrogen plasma (elec., H+, H2+, H3+), (b) neutral hydrogen atoms (H) and molecules (H2) in the gas phase, and (c) the wall‐stored H atoms. The model has been applied to simulate long‐term operation in the limiter configuration of the QUEST tokamak. Modelling results of the long time evolution of the H atom wall inventory reasonably reproduce the experimental tendency. Although the present model is relatively simple, it is useful to understand the basic characteristics of overall plasma particle balance, the density control of the main plasma, and the H atom wall inventory for long‐term tokamak operation.

show abstract

Numerical study of atomic production rate in hydrogen negative ion sources with the effect of non-equilibrium electron energy distribution function

Cited by 23 publications

References 21 publications

Numerical and experimental study of atomic transport and Balmer line intensity in Linac4 negative ion source

Numerical and experimental study of atomic transport and Balmer line intensity in Linac4 negative ion source

Present status of numerical modeling of hydrogen negative ion source plasmas and its comparison with experiments: Japanese activities and their collaboration with experimental groups

Modelling of plasma and its wall interaction for long‐term tokamak operation

Contact Info

Product

Resources

About