Behaviors of impurity in ITER plasma with standard type I ELMy H-mode and steady-state scenarios

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Plasma Physics Reports

DOI:https://doi.org/10.1134/S1063780X10100016· OSTI ID:21443427

Pianroj, Y; Chuchinda, C ^[1]; Leekhaphan, P ^[2]; Onjun, T ^[1]

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1. Thammasat University, School of Manufactoring Systems and Mechanical Engineering, Sirindhorn International Institute of Technology (Thailand)
2. Thammasat University, School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology (Thailand)

Self-consistent simulations of impurity behaviors in ITER plasmas in standard Type I ELMy H-mode and steady-state scenarios are investigated using 1.5D BALDUR integrated predictive modeling code. In these simulations, the plasma core transports, including electron and ion thermal, hydrogenic and impurity transports, are predicted using a linear combination of anomalous and neoclassical transports. An anomalous transport is calculated using a theory-based Multimode (MMM95) model; while the neoclassical transport is calculated using NCLASS model. The temperature and density boundary conditions are described at the top of the pedestal. Two different models for hydrogenic and impurity boundary density conditions are considered. The first model is called a 'static boundary density model,' in which the hydrogenic and impurity densities at the boundary are fixed. For the second model, called a 'dynamic boundary density model,' the hydrogenic and impurity densities at the boundary are assumed to be a large fraction of its line-averaged density. For simplicity, the pedestal temperature is assumed to be a constant in all simulations. The combination of a core transport model together with the boundary density models is used to simulate the time evolution of plasma current, temperature, and density profiles for ITER plasmas in standard type I ELMy H-mode and steady-state scenarios. As a result, the behaviors of impurity in ITER plasmas can be investigated. It is found in both ITER scenarios that the total amount of impurity, including beryllium and helium, in plasma core increases rapidly in early state and reaches a steady-state value. The level of impurity content in the steady state depends sensitively on the impurity boundary conditions. The effective charge at the edge is found to be about 1.4 and 1.1 using a static boundary density model and a dynamic boundary density model, respectively. It is also found that the hydrogenic and impurity transports in ITER plasmas for both scenarios is dominated by the kinetic ballooning modes, while the ITG and TEM modes provide the largest contributions for both thermal transports in most of region. In addition, a sensitivity study is carried out to investigate the impacts of pedestal temperature, pedestal density and line-averaged density on the impurity behaviors. It is found that increasing the pedestal temperature results in a reduction of the impurity content. On the other hand, increasing the pedestal density, line-averaged density or impurity influx result in an increase of the impurity content.

• OSTI ID: 21443427
• Journal Information: Plasma Physics Reports, Vol. 36, Issue 10; Other Information: DOI: 10.1134/S1063780X10100016; Copyright (c) 2010 Pleiades Publishing, Ltd.; ISSN 1063-780X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BERYLLIUM
BOUNDARY CONDITIONS
DENSITY
EDGE LOCALIZED MODES
ELECTRIC CURRENTS
HELIUM
ITER TOKAMAK
NEOCLASSICAL TRANSPORT THEORY
PLASMA
PLASMA IMPURITIES
SIMULATION
STEADY-STATE CONDITIONS
ALKALINE EARTH METALS
CHARGED-PARTICLE TRANSPORT THEORY
CLOSED PLASMA DEVICES
CURRENTS
ELEMENTS
FLUIDS
GASES
IMPURITIES
INSTABILITY
METALS
NONMETALS
PHYSICAL PROPERTIES
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RARE GASES
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS
TRANSPORT THEORY