Deuterium recycling and wall retention characteristics during boron powder injection in EAST

Boron (B), as a low-Z material, is widely employed for wall conditioning to enhance plasma performance in fusion devices. In the Experimental Advanced Superconducting Tokamak, a series of experiments involving real-time B powder injection has been conducted to investigate fuel particle behavior. It...

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Bibliographic Details
Main Authors: G Z Zuo, Z Wang, Z Sun, W Xu, Z T Zhou, Y H Guan, M Huang, R Maingi, J S Hu
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:Materials Research Express
Subjects:
Online Access:https://doi.org/10.1088/2053-1591/ad1355
Description
Summary:Boron (B), as a low-Z material, is widely employed for wall conditioning to enhance plasma performance in fusion devices. In the Experimental Advanced Superconducting Tokamak, a series of experiments involving real-time B powder injection has been conducted to investigate fuel particle behavior. It was observed that fuel particle recycling decreased with an increase in the amount of B powder injected, resulting in an increase in short-term fuel retention. The fuel recycling decreased by up to 80%, as indicated by divertor neutral pressure and D α line emission. Furthermore, each B atom exhibited a trapping capacity of 0.3 D particles during B powder injection at a typical flow rate. The real-time B injection had no wall hysteresis effect on D retention, implying that cumulative B injection and deposited film did not affect long-term D retention. The possible mechanism for D retention is the formation of B-C-O-D compounds and co-deposition between B and D particles during discharges. This investigation would be valuable for evaluating T retention when B is used as wall conditioning material in future fusion reactor devices.
ISSN:2053-1591