HL-1M弹丸加料等离子体中约束改善和MHD特性研究  

IMPROVED CONFINEMENT CHARACTERISTICS AND CENTRAL MHD ACTIVITY IN PELLET FUELED HL 1M PLASMA

作　　者：刘仪[1] 郭干城[1] 钟云泽 肖正贵[1] 付炳忠[1] 董贾福[1] 

机构地区：[1]核工业西南物理研究院

出　　处：《核聚变与等离子体物理》1999年第3期171-177,共7页Nuclear Fusion and Plasma Physics

摘　　要：在ＨＬ－１Ｍ装置实验中，多发弹丸注入在ｑ＝１磁面内区域产生了高度峰化的密度和压强分布，明显改善了等离子体约束特性。标志着弹丸注入约束改善的峰化的密度、压强分布，在出现第一个大锯齿后平化。弹丸注入后的锯齿崩溃，在密度和压强峰化因子均较高时，具有在更高密度、更高压强下才出现的类理想的特性。随着弹丸穿透加深，芯部区域的密度（压强）梯度变陡，中心ＭＨＤ活性受到弹丸注入的强烈影响，锯齿崩溃特征从完全重连型变成部分重连型，并在崩溃过程中ｍ＝１模的发展与一个非常定域的密度扰动相耦合。Multi pellets were injected into the HL 1M tokamak plasma, high fuelling efficiencies were observed. Improved energy confinement for ohmic discharge has been obtained with multi pellet injection. The energy confinement is enhanced by up to 30% over that of usual gas fuelled discharges, and a strongly peaked electron density profile of n e (0)/〈n e〉<2 at n e (0)≈5×10 13 cm -3 is sustained for about 50ms. The peak depends strongly on the penetration length of the pellets and the characteristics of MHD activities change with peaking of pressure profile produced by the pellet injection. When the pellets penetrate inside or close to r s , the sawtooth activity can be suppressed, and the density peaking and sawtooth suppression are closely linked. MHD activities play an important role in limiting the attainable central plasma pressure. The improved discharges characterized by a highly peaked pressure profile inside q=1 surface are degraded by a large sawtooth collapse. At this sort of large sawthooth collapse, the central kinetic energy is released slowly through a very localized density perturbation on a prolonged HL 1M time scale.

关 键 词：改善约束 MHD活性 弹丸注入 HL-1M 托卡马克 

分 类 号：TL631.24[核科学技术—核技术及应用] TL612