Speaker
Description
Addressing the effect of E×B on closure diveror detachment onset by SOLPS
Hailong Du, Guoyao Zheng, Jiaxian Li
Southwestern Institute of Physics, PO Box 432, Chengdu 610041, People’s Republic of China
Email: duhl@swip.ac.cn
Abstract
The closed divertor (such as small angle slot-SAS, C-Mod)[1] can well trap neutral (D, D2) and carbon impurity from erosion particles in target region, so that the impurity and recycling neutral particles can radiate a large quantity of power[2]. As a result, the closed divertor very easily achieves detachment with relative small upstream density. However, experimental results in DIII-D and C-Mod [3]showed that the direction of Grad-B has very big influence on the closed diveror detachment onset. As we known, the electric drift- E×B is much related with the direction of Grad-B, and can drive a large number of particles from outer into inner target region along the poloidal flux tubes in private flux region when Grad-B toward divertor. The E×B strongly depends on the radial and polodial gradients of electron temperature-Te and static pressure-neTe[4]. Since the closed divertor can well screen impurity and neutral recycling particles, the polodial gradients of Te and neTe are much larger in closed divertor than that open divertor. Thus, the E×B may have a great effect on the detachment onset in closed divertor. In this work, we will employ the edge plasma code SOLPS to address the effect of E×B on the closed diveror detachment onset in HL-2M. The preliminary modeling results reveal that the effect of E×B on detachment onset in closed divertor is much larger than open divertor, and the closed divertor is very difficult to achieve detachment when Grad-B toward divertor when activating E×B. This work will excite great interests in advancing scientific understanding of the interplay between E×B and impurity energy dissipation for detachment control in closed divertor.
References
[1] Guo H Y, Sang C F, Stangeby P C, Lao L L, Taylor T S and Thomas D M 2017 Small angle slot divertor concept for long pulse advanced tokamaks Nucl. Fusion 57
[2] Sang C, Guo H Y, Stangeby P C, Lao L L and Taylor T S 2017 SOLPS analysis of neutral baffling for the design of a new diverter in DIII-D Nucl. Fusion 57 065043
[3] Lipschultz B, LaBombard B, Terry J L, Boswell C and Hutchinson I H 2007 Divertor physics research on alcator C-Mod Fusion Sci. Technol. 51 369–89
[4] Du H, Sang C, Wang L, Bonnin X, Wang H, Sun J and Wang D 2017 Role of E × B on in–out divertor asymmetry in high recycling/partial detachment regimes under L-mode and H-mode conditions Nucl. Fusion 57 116022
| Country or International Organization | China, People’s Republic |
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