Upgrade of Langmuir probe diagnostic in ITER-like tungsten mono-block divertor on experimental advanced superconducting tokamak

Journal Article · Mon Aug 15 00:00:00 EDT 2016 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4960181· OSTI ID:22597679

Xu, J. C.; Jia, M. N.; Feng, W.; Deng, G. Z. ^[1]; Xu, G. S.; Luo, G. N.; Yao, D. M.; Li, Q.; Cao, L.; Chen, L.; Zhang, W.; Liu, S. C.; Wang, H. Q.; Hu, L. Q.; Wan, B. N.; Li, J.; Sun, Y. W. ^[1]; Guo, H. Y. ^[1]

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1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

In order to withstand rapid increase in particle and power impact onto the divertor and demonstrate the feasibility of the ITER design under long pulse operation, the upper divertor of the EAST tokamak has been upgraded to actively water-cooled, ITER-like tungsten mono-block structure since the 2014 campaign, which is the first attempt for ITER on the tokamak devices. Therefore, a new divertor Langmuir probe diagnostic system (DivLP) was designed and successfully upgraded on the tungsten divertor to obtain the plasma parameters in the divertor region such as electron temperature, electron density, particle and heat fluxes. More specifically, two identical triple probe arrays have been installed at two ports of different toroidal positions (112.5-deg separated toroidally), which can provide fundamental data to study the toroidal asymmetry of divertor power deposition and related 3-dimension (3D) physics, as induced by resonant magnetic perturbations, lower hybrid wave, and so on. The shape of graphite tip and fixed structure of the probe are designed according to the structure of the upper tungsten divertor. The ceramic support, small graphite tip, and proper connector installed make it possible to be successfully installed in the very narrow interval between the cassette body and tungsten mono-block, i.e., 13.5 mm. It was demonstrated during the 2014 and 2015 commissioning campaigns that the newly upgraded divertor Langmuir probe diagnostic system is successful. Representative experimental data are given and discussed for the DivLP measurements, then proving its availability and reliability.

• OSTI ID: 22597679
• Journal Information: Review of Scientific Instruments, Vol. 87, Issue 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CONNECTORS
DESIGN
DIVERTORS
ELECTRON DENSITY
ELECTRON TEMPERATURE
ELECTRONS
GRAPHITE
HEAT
HEAT FLUX
HT-7U TOKAMAK
ITER TOKAMAK
LANGMUIR PROBE
LOWER HYBRID CURRENT DRIVE
LOWER HYBRID HEATING
OPERATION
PARTICLES
PERTURBATION THEORY
TUNGSTEN
WATER
WATER COOLED REACTORS