Real-time control of divertor detachment in H-mode with impurity seeding using Langmuir probe feedback in JET-ITER-like wall
Real-time control of divertor detachment in H-mode with impurity seeding using Langmuir probe feedback in JET-ITER-like wall
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DOI：
10.1088/1361-6587/aa5951
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发表时间：
2017-04-01
影响因子：
2.2
通讯作者：
Zychor, I.
中科院分区：
文献类型：
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作者：
Guillemaut, C.;Lennholm, M.;Zychor, I.
在热核实验堆上燃烧具有500兆瓦聚变功率的等离子体将依靠部分分离的偏滤器操作，以将目标热负荷保持在可管理的水平。这样的偏滤器状态将由一个实时控制系统来维持，该控制系统使用像氮(N)、霓虹或氩这样的辐射杂质作为致动器，并使用一个或多个诊断信号作为传感器。最近，在I型Elmy H型JET-ITER类壁放电中，利用偏滤器朗缪尔探头的饱和电流(I-sat)测量作为反馈信号，成功地实现了对偏滤器脱离的实时控制，以控制N种子的水平。通过比较外靶峰值i-sat测量值和翻滚时的峰值i-sat值，实时计算偏滤器脱离程度，以控制N喷射阀的开启。在定点和扫射打击点实验中，均实现了脱体的实时控制。该系统已经逐步得到改进，现在可以自动将偏滤器的状态从附着状态通过高回收和滚动向下驱动到用户定义的分离级别。这一演示成功地证明了热核实验堆今后运作的原则，热核实验堆将广泛配备偏滤器靶标探测器。
Burning plasmas with 500 MW of fusion power on ITER will rely on partially detached divertor operation to keep target heat loads at manageable levels. Such divertor regimes will be maintained by a real-time control system using the seeding of radiative impurities like nitrogen (N), neon or argon as actuator and one or more diagnostic signals as sensors. Recently, real-time control of divertor detachment has been successfully achieved in Type I ELMy H-mode JET-ITER-like wall discharges by using saturation current (I-sat) measurements from divertor Langmuir probes as feedback signals to control the level of N seeding. The degree of divertor detachment is calculated in real-time by comparing the outer target peak I-sat measurements to the peak I-sat value at the roll-over in order to control the opening of the N injection valve. Real-time control of detachment has been achieved in both fixed and swept strike point experiments. The system has been progressively improved and can now automatically drive the divertor conditions from attached through high recycling and roll-over down to a user-defined level of detachment. Such a demonstration is a successful proof of principle in the context of future operation on ITER which will be extensively equipped with divertor target probes.