物理学报2025，Vol.74Issue(8)：139-145,7.DOI:10.7498/aps.74.20241605
电子回旋共振激发氘负离子数密度的光发射谱诊断
Diagnosis of number density of negative deuterium ions excited by electron cyclotron resonance by optical emission spectroscopy
摘要
Abstract
The electron cyclotron resonance(ECR)plasma is characterized by low working pressure and high dissociation rate,and it has important applications in the deuterium negative ion D-source technology.In this paper,the Yacora collisional-radiative model is applied to the emission spectrum diagnosis of D-in ECR deuterium plasma.The D-density is estimated by using the IDα/IDβ ratio and the relative intensity of other deuterium molecular lines,thereby avoiding complex calibration procedure of absolute intensity.The spatial structure of D-is studied by the multichannel emission spectrum measured in the source region and diffusion region. The experiments are conducted on a 2.45-GHz ECR plasma source at a deuterium gas pressure of 1 Pa and microwave power of 660 W.The Balmer series of atomic deuterium(Dα,Dβ,Dγ,Dδ)and the Fulcher band Q-branches of molecular deuterium are measured in the source region and expanding region of the ECR plasma.It is found that the intensity of Dα in the source region is much higher than that of Dβ,specifically,the IDα/IDβ ratio reaches as high as 23,indicating a selective enhancement of Balmer lines due to the mutual neutralization process of D-.Furthermore,D-density in the source region is estimated to be about 3.6 × 1015 m-3,and the D-density in the expanding region decreases significantly.In the ECR plasma source region,the plasma-wall interaction is strong due to the small volume of the cavity.The recombination desorption process produces more vibrationally excited molecules,thereby further enhancing the dissociation attachment reaction,which is beneficial to the generation of deuterium negative ions.On the other hand,the axial electric field within the ECR plasma inhibits the axial transport of D-,suggesting that the production and loss of D-are both localized.These characteristics of the ECR plasma source contribute to the formation of a large gradient of D-density between the source region and the expanding region.关键词
氘负离子源/发射光谱/电子回旋共振等离子体Key words
negative deuterium ion sources/optical emission spectroscopy/electron cyclotron resonance plasma引用本文复制引用
陈越,朱晓东..电子回旋共振激发氘负离子数密度的光发射谱诊断[J].物理学报,2025,74(8):139-145,7.基金项目
国家磁约束核聚变能发展研究专项(批准号:2018YFE0301102)资助的课题. Project supported by the National MCF Energy R&D Program of China(Grant No.2018YFE0301102). （批准号:2018YFE0301102）
