EXL-50研究进展与未来计划概述
Overview of EXL-50 Research Progress and Future Plan
AI总结：
EXL-50通过ECRH实现非感应电流驱动，研究高能电子和等离子体参数，计划升级设备以提升性能
摘要：
XuanLong-50（EXL-50）是中国首个中型球面托卡马克（ST），其主半径的磁场均约为0.5T，半径为50厘米。CS-free和非感应电流驱动是EXL-50的主要物理研究问题，通过电子旋磁共振加热（ECRH）实现。在EXL-50中，可以常规获得等离子体电流为50kA-180kA的放电，电流峰值可维持达2秒或更长。使用28GHz ECRH单独加热功率低于200kW时，电流驱动效率可高达1A/W。在高密度（5×10^18m^-2）放电中，150kW 28GHz ECRH可使等离子体电流达到Ip>80kA。使用150kW 50GHz ECRH可实现更高性能放电（Ip约为120kA，核心密度约为1×10^19m^-3）。EXL-50的等离子体电流主要由高能电子携带。多流体平衡模型已成功应用于重建EXL-50平衡的磁通面和测量的等离子体参数。还研究了无磁环ECRH电流驱动和高能电子的物理机制。初步实验结果表明，100kW的低混频电流驱动（LHCD）波可驱动20kA的等离子体电流。在EXL-50中安装并测试了多个硼注入系统，包括B2H6气体填充、硼粉注入、硼丸注入。还提出了EXL-50U（EXL-50的升级机）的研究计划。
英文摘要：
XuanLong-50 (EXL-50) is the first medium-size spherical torus (ST) in China, with the toroidal field at major radius at 50 cm around 0.5T. CS-free and non-inductive current drive via electron cyclotron resonance heating (ECRH) was the main physics research issue for EXL-50. Discharges with plasma currents of 50 kA - 180 kA were routinely obtained in EXL-50, with the current flattop sustained for up to or beyond 2 s. The current drive effectiveness on EXL-50 was as high as 1 A/W for low-density discharges using 28GHz ECRH alone for heating power less than 200 kW. The plasma current reached Ip>80 kA for high-density (5*10e18m-2) discharges with 150 kW 28GHz ECRH. Higher performance discharge (Ip of about 120 kA and core density of about 1*10e19m-3) was achieved with 150 kW 50GHz ECRH. The plasma current in EXL-50 was mainly carried by the energetic electrons.Multi-fluid equilibrium model has been successfully applied to reconstruct the magnetic flux surface and the measured plasma parameters of the EXL-50 equilibrium. The physics mechanisms for the solenoid-free ECRH current drive and the energetic electrons has also been investigated. Preliminary experimental results show that 100 kW of lower hybrid current drive (LHCD) waves can drive 20 kA of plasma current. Several boron injection systems were installed and tested in EXL-50, including B2H6 gas puffing, boron powder injection, boron pellet injection. The research plan of EXL-50U, which is the upgrade machine of EXL-50, is also presented.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
