Sputtering Yield Calculation of Some Candidate PFC Materials

In order to estimate the erosion rates of some plasma facing component materials, the sputtering yields of Mo, W and Li bombarded by charged particles H^ , D^ , T^ and He^ are calculated by application of sputtering theory based on bipartition model of ion transport. The comparisons with Monte-Carlo calculation results are made. These data might be useful to estimate the lifetime of plasma facing components and to analyze the impurity level in core plasma of fusion reactors.     

Development of New Type Multi-Elements Doped Carbon-Base Plasma Facing Materials

Carbon-base materials will be major plasma facing materials (PFM) in a fusion device in near term and even in the future in spite of its high tritium trapping and chemical sputtering yield. Of course, the development of high Z PFM and free surface system are also important for fusion energy.     

Installation and Primary Results of a Neutral Particle Analyzer on HL-2A Tokamak

The target of nuclear fusion research is to realize effective and sustainable fusion reaction of hydrogen isotope ions and to get the thermonuclear energy economically. Naturally the parameters of plasma ions are of importance and measurement of the parameters of ions has been an essential concern to the nuclear fusion research work since 1950s. However, the ions are confined by the mag- netic field, one can measure the neutral particles emitting from the plasma to obtain the parameters of ions. The diagnosing of neutral particles is a method by measuring the neutral particles from the plasma to obtain the information （such as energy） of ions, and it is important and foundational to the experi ments as well.     

Study of the Effects of Liquid Lithium Curtain as First Wall on Plasma

The final goal of fusion energy research is to make it economically competitive and the cost of electricity (COE) as low as acceptable by the energy market. Therefore the fusion plasma has to be operating with high power density and the plasma facing components (PFC), such as first wall and divertor, have to sustain high surface heat load and bombardment with high particle flux. Such rigorous environments consequentially lead to severe damage and erosion of PFC materials. As a result, the lifetime of PFC would be shortened.     

Experimental Results on Performance Improvement of Doped Carbon-base Materials

Carbon-base materials is one of candidate plasma facing materials and have been widely used in current tokamak facilities in the world. But some defect properties are presented on high yield of chemical sputtering, high yield of radiation enhancement sublimate (RES), cracking after heat flux in divertor and so on. These characteris are related to the interstitial carbon atom producing and mobile, so it can be improved by doped some little other elements into the carbon-base materials, such as boron, silicon, titanium and so on.     

Formation of a disordered region at the grain boundary during migration with He atoms

<正>W is considered a potential candidate as a plasma facing material for future nuclear fusion devices because of its high melting point,low sputtering rate,and low H or He solubility[1-3].In a fusion environment,W will be in direct contact with heat flux,H/He particle fluxes,and the irradiation of high-energy neutrons,causing several defects to be generated,which decrease the service life of W materials.The     

Electronic transport of Lorentz plasma with collision and magnetic field effects

The electronic transverse transport of Lorentz plasma with collision and magnetic field effects is studied by solving the Boltzmann equation for different electron density distributions. For the Maxwellian distribution, it is shown that transport coefficients decrease as ? increases, ? is the ratio of an electron's magneto-cyclotron frequency to plasma collision frequency. It means that the electrons are possible to be highly collimated by a strong magnetic field. For the quasimonoenergetic distribution with different widths, it is found that the transport coefficients decrease greatly as εˉ decreases.In particular when the width approaches to zero the transverse transport coefficients are hardly affected by the magnetic field and the minimal one is obtained. Results imply that the strong magnetic field and quasi-monoenergetic distribution are both beneficial to reduce the electronic transverse transport. This study is also helpful to understand the relevant problems of plasma transport in the background of the inertial confinement fusion.     

Effects of a liquid lithium curtain as the first wall in a fusion reactor plasma

This paper explores the effect of a liquid lithium curtain on fusion reactor plasma, such curtain is utilized as the first wall for the engineering outline design of the Fusion Experimental Breeder （FEB-E）. The relationships between the surface temperature of a liquid lithium curtain and the effective plasma charge, fuel dilution and fusion power production have been derived. Results indicate that under normal operation, the evaporation of liquid lithium does not seriously affect the effective plasma charge, but effects on fuel dilution and fusion power are more sensitive. As an example, it has investigated the relationships between the liquid lithium curtain flow velocity and the rise of surface temperature based on operation scenario II of the FEB-E design with reversed shear configuration and high power density. Results show that even if the liquid lithium curtain flow velocity is as low as 0.5 m/s, the effects of evaporation from the liquid lithium curtain on plasma are negligible. In the present design, the sputtering of liquid lithium curtain and the particle removal effects of the divertor are not yet considered in detail. Further studies are in progress, and in this work implication of lithium erosion and divertor physics on fusion reactor operation are discussed.[第一段]     

Radiative divertor behavior and physics in Ar seeded plasma on EAST

To investigate the radiative divertor behavior and physics for the scenario of impurity seeded plasma in ITER, the radiative divertor experiments with argon(Ar) seeding under ITER-like tungsten divertor condition were carried out during recent EAST campaigns. The experimental results reveal the high efficiency of reducing heat load and particle flux onto the divertor targets owing to increased radiation by Ar seeding. We achieve detached plasmas in these experiments. The inner–outer divertor asymmetry reduces after Ar seeding. Impurities, such as Ar, C, Li, and W, exist in the entire space of the vacuum chamber during EAST operations, and play important roles in power exhausting and accelerating the plasma detachment process. It is remarkable that the contamination of the core plasma is observed using Ar seeding owing to the sputtering of plasma facing components(PFCs), particularly when Ar impurity is injected from the upper tungsten divertor.