Effects of impurity seeding in DIII-D radiating mantle discharges
Effects of impurity seeding in DIII-D radiating mantle discharges
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DOI：
10.1088/0029-5515/42/1/305
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发表时间：
2002
期刊：
影响因子：
3.3
通讯作者：
G. Jackson;M. Murakami;G. Mckee;D. Baker;J. Boedo;R. L. Haye;C. Lasnier;A. Leonard;A. Messiaen;J. Ongena;G. Staebler;B. Unterberg;M. Wade;J. Watkins;W. West
中科院分区：
文献类型：
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作者：
G. Jackson;M. Murakami;G. Mckee;D. Baker;J. Boedo;R. L. Haye;C. Lasnier;A. Leonard;A. Messiaen;J. Ongena;G. Staebler;B. Unterberg;M. Wade;J. Watkins;W. West
在DIII-D中，惰性气体杂质注入被用来增加地幔区域的辐射，在转移和限制放电中，约束增强高于ITERL-89 PL模式标度关系。对于具有L模式边缘的放电，杂质注入产生约束的迅速增加和密度的更逐渐增加。这些变化发生在密度和辐射功率分数显着低于TEXTOR托卡马克装置中观察到的。ELMing H模式放电与主动泵浦和高氘气进料（puff和泵）表现出密度的增加，没有退化的能量约束后，杂质注入，增加到近格林沃尔德密度极限后，自发过渡几百毫秒后，杂质注入。L模和ELMing H模辐射地幔放电的最高密度相通常在n = 2的MHD活动开始后终止，被确定为m/n = 3/2的新古典撕裂模。在地幔区域中的杂质注入后的密度波动的减少已被测量使用束发射光谱在L模式放电，是一致的热扩散率的减少和增加的核心环形旋转。这些类型的杂质籽晶放电之间的相似性和差异。
Impurity injection with noble gases has been used in DIII-D to increase radiation in the mantle region, with confinement enhancements above the ITERL-89P L mode scaling relation in both diverted and limited discharges. For discharges with an L mode edge, impurity injection produces a prompt increase in confinement and a more gradual increase in density. These changes occur at densities and radiated power fractions significantly lower than those observed in the TEXTOR tokamak device. ELMing H mode discharges with active pumping and high deuterium gas feed (puff and pump) exhibit an increase in density with no degradation in energy confinement after impurity injection, increasing to nearly the Greenwald density limit following a spontaneous transition several hundred milliseconds after impurity injection. The highest density phase of both L mode and ELMing H mode radiating mantle discharges is usually terminated after the onset of n = 2 MHD activity, identified as an m/n = 3/2 neoclassical tearing mode. A reduction in density fluctuations after impurity injection in the mantle region has been measured using beam emission spectroscopy in L mode discharges and is coincident with reductions in thermal diffusivity and increases in core toroidal rotation. The similarities and differences between these types of impurity seeded discharge will be presented.