无需螺旋线的电流驱动：通过ECRH在EXL-50球面反堆等离子体中实现
Solenoid-free current drive via ECRH in EXL-50 spherical torus plasmas
AI总结：
EXL-50实验通过ECRH实现无需螺旋线的电流驱动，利用高能电子维持高电流放电，验证了低长宽比磁约束对等离子体平衡的作用。
摘要：
作为一项新的球面托卡马克（ST）实验，EXL-50旨在简化未来核聚变电源的工程要求，其真空舱具有低长宽比（A）的结构，围绕中央柱组件，其中包含极向场线圈导体，而没有中央螺旋线。多个电子旋磁共振加热（ECRH）共振位于真空舱内，以提高电流驱动效果。大量高能电子被产生并测量，通过硬X射线探测器检测到，携带等离子体电流范围从50kA到150kA，持续时间超过1秒。观察到每瓦ECRH功率可维持超过一安培的电流。高密度（>5e18me-2）放电中，150kW ECHR加热可使等离子体电流达到Ip>80kA。通过结合重建的多流体平衡、高能电子的引导中心轨道和共振加热机制进行了分析。验证了在EXL-50中，广泛分布的高能电子电流创造了低长宽比的较小闭合磁通量面，从而约束热等离子体电子和离子，并参与维持平衡力平衡。
英文摘要：
As a new spherical tokamak (ST) designed to simplify engineering requirements of a possible future fusion power source, the EXL-50 experiment features a low aspect ratio (A) vacuum vessel (VV), encircling a central post assembly containing the toroidal field coil conductors without a central solenoid. Multiple electron cyclotron resonance heating (ECRH) resonances are located within the VV to improve current drive effectiveness. Copious energetic electrons are produced and measured with hard X-ray detectors, carry the bulk of the plasma current ranging from 50kA to 150kA, which is maintained for more than 1s duration. It is observed that over one Ampere current can be maintained per Watt of ECRH power issued from the 28-GHz gyrotrons. The plasma current reaches Ip>80kA for high density (>5e18me-2) discharge with 150kW ECHR heating. An analysis was carried out combining reconstructed multi-fluid equilibrium, guiding-center orbits of energetic electrons, and resonant heating mechanisms. It is verified that in EXL-50 a broadly distributed current of energetic electrons creates smaller closed magnetic-flux surfaces of low aspect ratio that in turn confine the thermal plasma electrons and ions and participate in maintaining the equilibrium force-balance.
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。
