Investigation of E-Divertor Plasma during Simultaneous Injection of Hydrogen and Impurity Gases into GAMMA 10/PDX by Using the LINDA Code

This paper investigates the impact of Krypton (Kr) seeding on plasma parameters in the D-module of GAMMA 10/PDX experimentally based on the calorimeter, Langmuir probe and high-speed camera measurements. The heat flux distribution along the V-shaped target plate reduces with the increasing Kr injection. The time behavior of ion flux shows that it decreases with the increase of Kr seeding. The electron temperature (T e ) reduces significantly due to Kr seeding into the D-module. The electron density shows a so-called roll-over phenomenon during Kr seeding. The heat and ion fluxes reduce with the increasing Kr seeding into the D-module. Two-dimensional images captured by the high-speed camera also show that the emission intensity significantly reduces inside the V-shaped target at the higher Kr injection. These outcomes represent the impact of Kr seeding for generating the detached plasma.

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“…The reported phenomenology will be explained numerically by using the multi-fluid code "LINDA" [14][15][16].…”

Section: Discussionmentioning

confidence: 99%

Measurements of the Plasma Parameters in the D-Module of GAMMA 10/PDX during Impurity Gas Kr Injection

Islam

Nakashima

Hatayama

et al. 2019

Plasma and Fusion Research

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“…The beneficial knowledge obtained from this study may contribute for the optimization of fueling in future plasma confinement devices such as ITER and DEMO. The present DEGAS code could be coupled with the fluid code "LINDA" [15][16][17][18] to study the neutral transport in the D-module of GAMMA 10/PDX [19,20].…”

Section: Discussionmentioning

confidence: 99%

Sensitivity Check of Background Plasma Parameter during SMBI in the GAMMA 10 Central-Cell by 3-D Monte-Carlo Simulations

Islam

Kobayashi

Nishino

et al. 2019

Plasma and Fusion Research

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The gas fueling by supersonic molecular beam injection (SMBI) has been carried out in the world largest tandem mirror device GAMMA 10 and higher plasma density has been achieved compared with conventional gas-puffing. Three-dimensional Monte-Carlo code DEGAS is applied to GAMMA 10 and the spatial distribution of neutral particle density during SMBI is investigated. σ div is introduced as divergence angle index of the initial particle to simulate the molecular beam injected by SMBI. It is defined to be unity in the case of cosine distribution of the angular profile of launched particles. It is found that the particles are suppressed and localized in the injection point according to the reduction of divergence angle index, σ div and well explained the GAMMA 10 SMBI experimental results at divergence angle index, σ div = 0.33. In this paper the simulation is carried out in the different profiles of electron temperature in order to check the sensitivity of the background plasma parameter. The simulation results indicate that the penetration depth depended on the background plasma parameter, electron temperature.

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“…Numerical simulation is performed at the end-cell of the device by using the LINDA. [12][13][14][15][16][17][18] In the previous studies, the neutral profile is calculated by solving a 1D continuity equation under the constant neutral velocity. [12][13][14][15][16][17][18] A Kinetic Monte-Carlo Neutral Code (KMNC) is newly developed and the transport of hydrogen neutral particles was investigated under the condition of fixed background plasma parameters in the previous study.…”

Section: Introductionmentioning

confidence: 99%

“…[12][13][14][15][16][17][18] In the previous studies, the neutral profile is calculated by solving a 1D continuity equation under the constant neutral velocity. [12][13][14][15][16][17][18] A Kinetic Monte-Carlo Neutral Code (KMNC) is newly developed and the transport of hydrogen neutral particles was investigated under the condition of fixed background plasma parameters in the previous study. [18] In this present calculation case, both the fluid and the neutral code are numerically solved in the self-consistence manner.…”

Section: Introductionmentioning

confidence: 99%

Impact of neutral gas puffing on the divertor power exhaust and particle control in GAMMA 10/PDX by the LINDA‐KNMC code

Islam

Nakashima

Hatayama

et al. 2021

Contributions to Plasma Physics

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This paper numerically investigates the impact of neutral gas puffing on the divertor power exhaust and particle control in GAMMA 10/PDX applying the plasma fluid code LINDA and the kinetic neutral code KMNC. The LINDA code is applied to GAMMA 10/PDX plasmas for understanding the physics of detachment and energy loss processes. The LINDA code is coupled with a Monte-Carlo neutral code for describing the hydrogen (H and H 2 ) neutral particles. The plasma ion temperature (T i ) is reduced towards the target plate with the increment of H 2 Gas-Puff rate. This paper also numerically investigates the impact of recombination processes on the detached formation. The ionization, charge-exchange, and recombination of H have been included as a particle and an energy sink and source parts of the fluid equations. The reaction rate coefficient of molecular activated recombination (MAR) has been recently introduced in the LINDA code. In this paper, we study numerically the effect of MAR on the detached plasma. The MAR plays a dominant role in making the detached plasma. The simulation clarified that H neutral particles injection can effectively generate the detached plasma by enhancing the plasma-neutral collisions processes.

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Investigation of E-Divertor Plasma during Simultaneous Injection of Hydrogen and Impurity Gases into GAMMA 10/PDX by Using the LINDA Code

Cited by 9 publications

References 20 publications

Measurements of the Plasma Parameters in the D-Module of GAMMA 10/PDX during Impurity Gas Kr Injection

Measurements of the Plasma Parameters in the D-Module of GAMMA 10/PDX during Impurity Gas Kr Injection

Sensitivity Check of Background Plasma Parameter during SMBI in the GAMMA 10 Central-Cell by 3-D Monte-Carlo Simulations

Impact of neutral gas puffing on the divertor power exhaust and particle control in GAMMA 10/PDX by the LINDA‐KNMC code

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