Physics of high performance JET plasmas in DT
Physics of high performance JET plasmas in DT
复制标题
DT 中高性能 JET 等离子体的物理原理
DOI：
10.1088/0029-5515/39/9y/302
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发表时间：
1999
期刊：
影响因子：
3.3
通讯作者：
M. Watkins
中科院分区：
文献类型：
--
作者：
M. Watkins
欧洲联合环体最近使用氘氚混合物运行，开展了氢、氘、氘氚和氚的国际热核实验反应堆物理活动，完全通过遥控操作安装了Mark IIGB“气箱”偏滤器，并开始使用这一更封闭的偏滤器进行物理实验。DT实验创造了聚变功率的记录（16.1？MW）、聚变功率与等离子体输入功率之比（0.62和0.95？0.17如果可以在稳定状态下获得类似的等离子体）和聚变持续时间（4？MW为4？s）。一个大规模的氚供应和处理厂，第一次的同类，允许重复使用的20？g的氚现场供应99.3？向机器注入100克氚H？在DT模式下，模式阈值功率明显较低，但总体能量约束时间实际上没有变化（没有同位素效应）。DT中的无膨胀缩比“风洞”实验外推到ITER参数点火。标度接近陀螺玻姆，但质量依赖性是不正确的。将热等离子体能量分离为核心和基座贡献可以解决这种差异（导致核心的适当陀螺玻姆缩放），并且还可以解释高密度和高辐射功率下的约束退化。几种射频加热方案已在DT中成功测试，与计算结果吻合良好。α粒子加热已被清楚地观察到，并与经典的预期是一致的。内部传输障碍已建立在优化的磁剪切放电DT和稳态条件下已接近同时内部和边缘传输障碍。第一个结果与新安装的马克IIGB偏滤器表明，在偏滤器等离子体的对称性可以修改使用差分气体燃料，优化剪切放电可以产生和氪气吹气是有效的恢复L？模式边缘条件，并在这种放电中建立内部传输屏障。
The Joint European Torus (JET) has recently operated with deuterium-tritium (DT) mixtures, carried out an International Thermonuclear Experimental Reactor (ITER) physics campaign in hydrogen, deuterium, DT and tritium, installed the Mark IIGB `Gas Box' divertor fully by remote handling and started physics experiments with this more closed divertor. The DT experiments set records for fusion power (16.1?MW), ratio of fusion power to plasma input power (0.62, and 0.95?? 0.17 if a similar plasma could be obtained in steady state) and fusion duration (4?MW for 4?s). A large scale tritium supply and processing plant, the first of its kind, allowed the repeated use of the 20?g of tritium on-site to supply 99.3?g of tritium to the machine. The H?mode threshold power is significantly lower in DT, but the global energy confinement time is practically unchanged (no isotope effect). Dimensionless scaling `wind tunnel' experiments in DT extrapolate to ignition with ITER parameters. The scaling is close to gyro-Bohm, but the mass dependence is not correct. Separating the thermal plasma energy into core and pedestal contributions could resolve this discrepancy (leading to proper gyro-Bohm scaling for the core) and also account for confinement degradation at high density and at high radiated power. Several radiofrequency heating schemes have been tested successfully in DT, showing good agreement with calculations. Alpha particle heating has been clearly observed and is consistent with classical expectations. Internal transport barriers have been established in optimized magnetic shear discharges in DT and steady state conditions have been approached with simultaneous internal and edge transport barriers. First results with the newly installed Mark IIGB divertor show that the in-out symmetry of the divertor plasma can be modified using differential gas fuelling, that optimized shear discharges can be produced and that krypton gas puffing is effective in restoring L?mode edge conditions and establishing an internal transport barrier in such discharges.