Overview of the emissivity measurements performed in WEST: in situ and post-mortem observations
Overview of the emissivity measurements performed in WEST: in situ and post-mortem observations
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WEST 发射率测量概述：原位和事后观测
DOI：
10.1088/1741-4326/ac6f68
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发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
the WEST team
中科院分区：
文献类型：
--
作者：
J. Gaspar;Y. Corre;F. Rigollet;M. Aumeunier;E. Bernard;S. Brezinsek;X. Courtois;R. Dejarnac;M. Diez;L. Dubus;N. Ehret;N. Fedorczak;M. Firdaouss;M. Houry;M. Le Bohec;T. Loarer;C. Martin;V. Moncada;P. Moreau;C. Pocheau;P. Reilhac;E. Tsitrone;the WEST team
本文总结了在WEST运行的第一阶段期间，对WEST下偏滤器的面向等离子体单元（PFU）进行的发射率测量，该单元由块状钨（W）制成的主动冷却ITER式PFU和由石墨制成的惯性冷却PFU与钨涂层混合而成。现场评估的发射率和实验室测量后，删除W涂层石墨和ITER级PFU从WEST设备。的测量表现出一个复杂的图案，强烈的发射率变化作为空间和时间的函数，主要解释与磁平衡（打击点位置）的变化，以及在实验活动的等离子体性能。暴露的ITER级PFU表现出急剧的空间变化的发射率从0.05到0.85，在一个单块规模（12毫米）在过渡的侵蚀（罢工点位置）和沉积（罢工点位置旁边）的高场一侧的区域。在低场侧，发射率从撞击点位置处的0.12变化到在低场侧方向上几厘米远的0.2。曝光后的发射率范围远高于未曝光PFU的发射率变化，发射率为0.09至0.15。在W-涂层石墨PFU上进行的原位观察显示了在内部和外部撞击点位置的发射率的快速演变，通常是几个脉冲。讨论了从WEST启动到去除涂W石墨组件的整个空间分布及其因等离子体操作而产生的变化。
This paper summarizes the emissivity measurements performed on the plasma-facing units (PFU) of the WEST lower divertor during the first phase of WEST running with a mix of actively cooled ITER-like PFUs made of bulk tungsten (W) and inertially cooled PFUs made of graphite with a coating of tungsten. In situ assessments of the emissivity and laboratory measurements after removing the W-coated graphite and ITER-grade PFUs from the WEST device are shown. The measurements exhibit a complex pattern with strong emissivity variation as a function of space and time mainly explained with the variation of magnetic equilibrium (strike point location) as well as the plasma performances during the experimental campaigns. The exposed ITER-grade PFU exhibits sharp spatial variation of the emissivity from 0.05 to 0.85 at a monoblock scale (12 mm) at the transition of the erosion (strike point location) and deposition (next to the strike point location) areas on the high-field side. On the low-field side, the emissivity varies from 0.12 at the strike point location, to 0.2 a few cm away in the low-field-side direction. This emissivity range after exposure is much higher than the emissivity variation of unexposed PFU with emissivity from 0.09 to 0.15. In situ observation performed on the W-coated graphite PFU shows a rapid evolution, typically a few pulses, of the emissivity in the inner and outer strike point location. The whole spatial distribution is discussed as well as its variation due to the plasma operation from the start-up of WEST to the removal of the W-coated graphite components.