Dependence of ITER Per for mance on Pedestal Temper atur e, Aver age Electr on Density, Auxiliar y Heating Power , and Impur ity Content

Abstr act Self-consistent modeling of ITER has been carried out using the 1.5D BALDUR integrated predictive modeling code. In these simulations, a core transport model is described by a combination of an anomalous transport and a neoclassical transport. An anomalous transport is calculated using the Multimode (MMM95) core transport model, while a neoclassical transport is computed using the NCLASS model. At the reference design point, it is found that ITER fusion power production improves with the increase of pedestal temperature, average electron density, and auxiliary heating power. However, the power production reduces with the increase of impurity content. For the variation of the density and auxiliary heating power, the fusion Q increases linearly with both parameters. It is also found that the sawtooth mixing radius tends to decreases with increasing of pedestal temperature, average electron density and auxiliary heating power; however, it increases with impurity content. In addition, the sawtooth frequency tends to increase with the increase of heating power; but decrease with pedestal temperature. Intr oduction The concept of magnetic confinement fusion (MCF) has long been explored to address the feasibility of nuclear fusion energy. The ITER project [1] is an international collaboration to investigate the scientific and technological feasibility of MCF. Producing fusion reactions which satisfy such a condition inside a tokamak requires our ability to both heat and contain high-temperature plasmas. Comprehensive computer simulations are needed to optimize to plasma conditions before actual experiments are carried on. In this study, the BALDUR integrated predictive modelling code [2] is used to carry out simulations of plasmas with the standard H-mode (high confinement) scenario, as it is the 35th EPS Conference on Plasma Phys. Hersonissos, 9 -13 June 2008 ECA Vol.32D, P-4.040 (2008 < Results and Discussions The BALDUR integrated predictive transport modeling code is used to carry out the until the pedestal temperature of 8 keV. This trend of nuclear fusion performance can be explained by the behavior of central temperature and density, which tend to decrease when the pedestal temperature is more than 8 keV. It can be also seen than the performance increase linearly with average electron density. However, the performance decreases when the auxiliary heating power or impurity content increases. The effect of pedestal temperature, average electron density, auxiliary heating power, and impurity content (Z eff ) variations on sawtooth oscillation is also investigated. Note that in all simulations, the sawtooth oscillation is considered after 15 sec until 597 sec. The sawtooth frequency and sawtooth mixing radius are averaged during last 30 sec of each simulation. It is found that the sawtooth frequency ranges from 0.2 Hz to 0.5 Hz and the sawtooth mixing radius ranges from 0.8 m to 1.1 m. The sawtooth mixing radius tends to decreases with increasing of pedestal temperature, average electron density and auxiliary heating power; however, it increases with impurity content. In addition, the sawtooth frequency tends to increase with the increase of heating power; but decrease with pedestal temperature. Conclusions Self-consistent modeling of ITER has been carried out using BALDUR integrated code. At the reference design point, it is found that ITER fusion power production improves with the increase of pedestal temperature, average electron density, and auxiliary heating power. However, the power production reduces with the increase of impurity content. For the variation of the density and auxiliary heating power, the fusion Q increases linearly with both parameters. It is also found that the sawtooth mixing radius tends to decrease with increasing pedestal temperature, average electron density and auxiliary heating power; however, it increases with impurity content. In addition, the sawtooth frequency tends to increase with the increase of heating power; but decrease with pedestal temperature

Feasibility study of neutral beam injection in Thailand Tokamak-1

Thailand Institute of Nuclear Technology (TINT) is developing Thailand- 1 (TT-1) from a former device HT-6 M of China. The first hydrogen plasma will be initiated in 2023. To investigate high-β plasma and physics related to fast ions, TT-1 will be equipped with auxiliary heating systems. In this work, a feasibility study for installing a neutral beam injection (NBI) heating system in TT-1 is carried out. This work is motivated to characterize beam ion\u27s orbits in different injection angles and to explore a condition suitable in terms of higher heating efficiency. In this work, we assume that a hydrogen beam will be launched into the TT-1 plasma with an acceleration voltage of 20 kV. The orbit simulations using the gyromotion following code LORBIT are performed in various magnetic field equilibria, i.e., different plasma current (Ip), toroidal magnetic field strength (Bt), and the magnetic axis (Rax). Furthermore, beam ions are injected in different directions, i.e., tangential co-injection and tangential counter-injection. In the case of co-injection, beam ion loss is not significant, by about 6%, whereas beam ion loss fraction is evaluated to be 26–34% in the case of counter-injection. Also, it is found that the number of lost beam ions is significantly affected by changing Ip and Rax. The results obtained in this work will directly support the experiment plan for the high-performance plasmas, design of the fast-ion diagnostic system, and systematic understanding of beam ion\u27s confinement property and beam-ion-driven magnetohydrodynamic (MHD) instabilities in TT-1