It is shown details of magnetic filed structure of LHD and that the connection length of divertor filed lines are of the order of 10km. Based on these characteristics of the peripheral magnetic filed structure, it is proposed an analytical model for divertor plasma of LHD. Heat flow in chaotic field line region is analyzed and criterion for detached divertor plasma is obtained.
High strength high conductivity copper alloys will be used for heat sink materials of a high heat flux component of a fusion reactor. High energy neutron irradiation on these materials will cause atomic displacements and nuclear transmutation, which will lead to degradation of thermal conductivity and mechanical properties of the materials. These effects will be briefly reviewed with special emphasis on synergistic effects of displacements and transmutation. It should be kept in mind that even pure copper will be transformed into Cu-Ni-Zn alloy by fusion neutron irradiations. This effect on the thermal conductivity and mechanical properties cannot be ignored for long term use of copper alloys in neutron irradiation environment. We have been utilizing Cu-Ni-Zn alloys to simulate the effect of nuclear transmutation. Displacement damage with fusion neutrons has been simulated by ion irradiation with 2.4MeV copper self ions. Results of these experiments will be summarized.
In this study, high temperature thermal properties of hot pressing sintered TiB2 ceramics was investigated in order to determine the feasibility to the divertor plate of fusion materials. The thermal expansion coefficient was 8.2×10-6/K in a range of room temperature to 1073K. The thermal diffusivity and specific heat were measured by the laser flash method. The thermal diffusivity and specific heat increased with increasing temperature. The thermal conductivity was 57 to 75W/mK at temperatures from room temperature to 1273K.
For the experimental simulation of the LHD divertor, we have developed the high heat flux sheet plasma device. The device consists of the high heat flux plasma source, the fast scanning probe system, and the heat flow measurement system. As a result, the detached plasma in the end of the He sheet plasma was observed with increasing the H2 gas flow ratio.
For ultralarge-scale integrated (ULSI) circuit processes, two types of large-diameter plasma generation methods were studied. The one is a microwave plasma by employing a high-permittivity material window. The plasma was produced by the surface-wave and thus the density enhancement was observed with the high permittivity of the dielectric window material. The method was emphasized to be promising in producing a large-diameter plasma for ULSI processes, in particular for photo-resist asking. Another source is an RF plasma by employing a multimode antenna. A newly designed antenna with several loops and different modes enabled a large-diameter plasma production having a function of electron energy control. The electron energy was reduced by changing the azimuthal mode of antenna from m=0 to m=2 with no notable change in electron density. Thus it was concluded that the characteristic length for induction field reverse was essential in conjunction with electron free path.
Many acronymus are appeared in the nuclear fusion journals. This article tends to give the words in a phrase of which the acronymus are composed. The cited acronymus are listed in Tabe 1. The nuclear fusion devices or fusion facilities expressed as acronymus, together with their locastions, are also summarized in Table 1. It is hoped that the table will be useful to the users who engage in the nuclea fusion research. Suggestions for improvement of this article will be received from various users which will be much appreciated.