Energy confinement properties of H-mode discharges in the DIII-D tokamak
Energy confinement properties of H-mode discharges in the DIII-D tokamak
复制标题
DIII-D 托卡马克中 H 模式放电的能量限制特性
DOI：
10.1088/0029-5515/29/2/004
复制
发表时间：
1989
期刊：
影响因子：
3.3
通讯作者：
T. Taylor
中科院分区：
文献类型：
--
作者：
D. Schissel;K. Burrell;J. Deboo;R. Groebner;A. Kellman;N. Ohyabu;T. Osborne;M. Shimada;R. Snider;R. Stambaugh;T. Taylor
中性束加热的DIII-D扩展边界偏滤器放电在很宽的参数范围内表现出ASDEX般的H模式行为。氘H-模式能量约束为120 ms，保持接近欧姆值高达6 MW的中性束加热，其中它是2-2.5倍高于L-模式值在1 MA的等离子体电流。氢和氦的H-模式能量约束时间是相似的，基本上低于氘的H-模式约束时间。的H-模式的限制时间随着中性束功率的增加而减少，只有30%，优于L-模式的限制时间在5兆瓦。在氢和氘混合物的H模式下（[H]/[H+D] 40%），约束时间介于纯氢和氘情况下获得的值之间，随着等离子体电流线性增加（q95 > 3.2），并且随着中性束功率的增加而减少。在这些等离子体的约束质量为85毫秒每MA在5.6兆瓦的加热功率。非氘H模的较低能量约束和能量约束随中性束功率的退化都伴随着边缘局域模（ELM）振幅和频率的增加。不断变化的ELM特性使得确定固有同位素和中性束对约束的影响变得困难。对于BT < 0.9 T和q95 < 3的值，氘和氢/氘H模式中的限制质量劣化到接近L模式水平的值。这种能量约束的恶化与高β下的操作无关，而是由于锯齿和ELM之间的组合作用，该组合作用在低Q和低BT下变得更加明显。L模式能量约束与离子种类无关，与Kaye-Goldston标度符合得很好。Odajima-Shimomura标度在同位素质量依赖性方面与目前的L模式τE数据不一致;他们对氢L模式的预测超过目前测量的两倍。
Neutral beam heated DIII-D expanded boundary divertor discharges have exhibited ASDEX-like H-mode behaviour over a wide parameter range. The deuterium H-mode energy confinement of 120 ms remained near the Ohmic value for up to 6 MW of neutral beam heating, where it was 2-2.5 times higher than the L-mode value at a plasma current of 1 MA. The hydrogen and helium H-mode energy confinement times were similar and substantially below the deuterium H-mode confinement time. The H-mode confinement times decreased with increasing neutral beam power and were only 30% better than the L-mode confinement times at 5 MW. In an H-mode with a mixture of hydrogen and deuterium ([H]/[H+D] ≅ 40%), the confinement time was in between the values obtained in the pure hydrogen and deuterium cases, increased linearly with plasma current for q95 > 3.2, and decreased with increasing neutral beam power. The confinement quality in these plasmas was 85 ms per MA at a heating power of 5.6 MW. The lower energy confinement in the non-deuterium H-modes and the degradation of energy confinement with neutral beam power were both accompanied by an increase in the edge localized mode (ELM) amplitude and frequency. The changing ELM characteristics make a determination of the intrinsic isotopic and neutral beam effect on confinement difficult. For values of BT < 0.9 T and q95 < 3, the confinement quality in the deuterium and hydrogen/deuterium H-modes deteriorated to values near the L-mode level. This deterioration in energy confinement was not related to operation at high beta but instead appears to be due to a combined action between sawteeth and ELMs that becomes more pronounced at low q and low BT. L-mode energy confinement was independent of ion species and in good agreement with Kaye-Goldston scaling. Odajima-Shimomura scaling disagreed with the present L-mode τE data in terms of isotopic mass dependence; their prediction for the hydrogen L-mode exceeds the present measurements by a factor of two.
影响因子：
3.3
作者：
A. Gibson;T. Sekiguchi;K. Lackner;S. Bodner;R. Hancox
通讯作者：
A. Gibson;T. Sekiguchi;K. Lackner;S. Bodner;R. Hancox