title: Breakdown assisted by a novel electron drift injection in the J-TEXT tokamak.
abstract: A novel electron drift injection (EDI) system aiming to improve breakdown behavior has been designed and constructed on the Joint Texas EXperiment Tokamak Tokamak. Electrons emitted by the system undergo the E×B drift, ∇B drift and curvature drift in sequence in order to traverse the confining magnetic field. A local electrostatic well, generated by a concave-shaped plate biased more negative than the cathode, is introduced to interrupt the emitted electrons moving along the magnetic field line (in the parallel direction) in an attempt to bring an enhancement of the injection efficiency and depth. A series of experiments have demonstrated the feasibility of this method, and a penetration distance deeper than 9.5 cm is achieved. Notable breakdown improvements, including the reduction of breakdown delay and average loop voltage, are observed for discharges assisted by EDI. The lower limit of successfully ionized pressure is expanded.
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Nengchao
authors.initials: N
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yishun
authors.initials: Y
authors.lastname: Cen
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Dequan
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Rao
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Bichen
authors.initials: B
authors.lastname: Zou