CONTROL OF TURBULENT WAVES BY END PLATE BIASING

1)在本研究期间，研制了两套用于测量伽马10串联镜密度涨落和密度分布的诊断系统。i)在中心细胞质(z=2.4m)上新安装了70 GHz夫琅和费衍射仪。Ii)还设计了7-18 GHz和18-26 GHz、X模和O模反射计，并将其应用于中心单胞等离子体(z=0m和1.8m)，用于测量脉动的径向分布。2)通过在端板上对伽马10的两种工作模式施加偏置电压来实现对等离子体的电位控制。主要结果如下：i)在宽密度分布的ECRH启动模式中，通过增大径向电子…，抑制了满足漂移波色散关系的密度涨落更多的RIC场，不管它的符号是什么。湍流的抑制增强了等离子体参数，如密度和反磁环信号，降低了Halpha信号。ii)在密度分布较窄的ICRF-Start模式中，具有最低方位模数的旋转不稳定性主要是在形成禁闭势时激发的。通过施加适度的负偏压来降低径向电场，它们被抑制。iii)本研究表明，通过分段端板形成径向电势分布来控制等离子体不稳定性是可能的，从而抑制径向双极输运。3)反射仪已用于测量离子回旋频率范围(ICRF)的涨落。被确认为电磁阿尔芬离子回旋加速器(AIC)波。ii)研究表明，内部磁波动可以通过X-模和O-模信号的比率来确定。iii)反射仪还被用来监测所施加的ICRF，即ICRF功率的沉积分布。较少

1)During the period of this research project, two diagnostic systems have been developed for the measurements of density fluctuations as well as density profiles of the GAMMA 10 tandem mirror.i)The 70 GHz Fraunhofer-diffraction apparatus has been newly installed to the centrall cell plasma (z=2.4m). A new rectangular antenna array which functions as a spectroscopic slit in the plane of observation enabled to attain a good signal to noiseratio.ii)The 7-18 GHz and 18-26 GHz, X-mode and O-mode reflectometers were also designed and have applied to the centrall cell plasma (z=0m and 1.8m) for the meausrements of radial distribution of the fluctuations.2)The potential control of plasmas was carried out by applying a bias voltage to the end plates for two operational modes of GAMMA 10. The main results are the following.i)In the ECRH-start mode with broad density profiles, the density fluctuations satisfying the dispersion relation of drift waves were suppressed by increasing the radial elect … More ric field regardless of its sign. The suppression of turbulence allowed the enhancement of the plasma parameters such as the density and the diamagnetic loop signal, and lowered the Halpha signal.ii)In the ICRF-start mode with narrow density profiles, the rotational instabilities with the lowest azimuthal mode number were predominantly excited during the formation of confining potentials. They were supressed by applying the moderate negative bias to lower the radial electric field.iii)The present study shows that it is possible to control plasma instabilities by shaping the radial potential profiles using segmented end plates so as to suppress radial ambipolar transport.3)The reflectometers have been appllied for the measurement of fluctuations with ion cyclotron range of frequency (ICRF).i)The wave with omega<omega_<ci> was identified as the electromagnetic Alfven ion cyclotron (AIC) wave.ii)It was shown that the internal magnetic fluctuations can be determined from the ratio of X-to O-mode signals.iii)The reflectometers was also used to monitor the applied ICRF, the deposition profile of the ICRF power. Less