论文标题
蜘蛛RF来源的激光吸收诊断的设计和初步操作
Design and preliminary operation of a laser absorption diagnostic for the SPIDER RF source
论文作者
论文摘要
需要iTer加热中性束（HNB）喷油器才能从RF源产生的H-/D-负离子的中和束向血浆中传递16.7 MW的功率，并加速了1 MEV。为了增强H-/D-生产，由于其功能较低，CAS面向源的加速度系统网格表面将涂有CS。 CS将通过特定的烤箱在源中常规蒸发。监测源内CS的蒸发率和分布是至关重要的，可以在ITER HNB上获得所需的性能。为了正确设计ITER HNB的来源并确定最佳操作实践，在Consorzio RFX的中性光束测试设施中已经开发并建立了原型RF负离子源蜘蛛。蜘蛛中将安装激光吸收光谱诊断，以定量估计CS密度。通过使用波长可调激光器，诊断将沿着4条视线测量852 nm线的吸收光谱，平行于等离子体网格表面并靠近它。从吸收光谱中，将测量基态CS的线集成密度。介绍了蜘蛛诊断的设计，并提供了布局和关键组件的详细信息。还描述了在CS烤箱的测试架上的诊断初步安装，以及其第一个实验结果。讨论并部分纠正了基态减少对收集的测量的影响。
The ITER Heating Neutral Beam (HNB) injector is required to deliver 16.7 MW power into the plasma from a neutralised beam of H-/D- negative ions, produced by an RF source and accelerated up to 1 MeV. To enhance the H-/D- production, the surface of the acceleration system grid facing the source (the plasma grid) will be coated with Cs because of its low work function. Cs will be routinely evaporated in the source by means of specific ovens. Monitoring the evaporation rate and the distribution of Cs inside the source is fundamental to get the desired performances on the ITER HNB. In order to proper design the source of the ITER HNB and to identify the best operation practices for it, the prototype RF negative ion source SPIDER has been developed and built in the Neutral Beam Test Facility at Consorzio RFX. A Laser Absorption Spectroscopy diagnostic will be installed in SPIDER for a quantitative estimation of Cs density. By using a wavelength tunable laser, the diagnostic will measure the absorption spectrum of the 852 nm line along 4 lines of sight, parallel to the plasma grid surface and close to it. From the absorption spectra the line-integrated density of Cs at ground state will be measured. The design of this diagnostic for SPIDER is presented, with details of the layout and of the key components. A preliminary installation of the diagnostic on the test stand for Cs ovens is also described, together with its first experimental results; the effect of ground state depopulation on collected measurements is discussed and partially corrected.
