Performance study and comparison of vacuum RF circuits developed for first mirror plasma cleaning systems in ITER optical diagnostics

IF 1.9 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Fusion Engineering and Design Pub Date : 2025-04-17 DOI:10.1016/j.fusengdes.2025.115073

Andrey Ushakov , Cederik Meekes , Ulf Stephan , Olaff Steinke , Frank Stahr , Corné Rijnsent , Shriparna Mukherjee , Peter Giesen , André Rijfers , Ad Verlaan , Maarten de Bock , Eiichi Yatsuka , Michele Bassan , Lucas Moser , Erik van Beekum , Shobhit Yadav

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引用次数: 0

Abstract

In collection optics of many ITER optical diagnostics, first mirrors play a critical role for a robust optical system operation. To maintain the mirrors’ stable life-time performance, periodic in-situ plasma cleaning is developed using ion fluxes from a locally produced radio-frequency discharge. To enable efficient power transmission to the vacuum-plasma load, new impedance matching circuits were developed for installation behind the first mirror. Two new impedance matching prototypes were realized for two ITER large diagnostic systems (the Visible Spectroscopy Reference System and the Edge Thomson Scattering system). The prototype matching circuits comprising ceramic boards with metal layers were tested at the powers of 100–800 W at 40 MHz in the breadboards representing first mirror units of both systems to clean tungsten model contaminants. Frequency tuning was proposed as a lifetime measure to reduce the reflected power. Sputtering results in argon and helium plasma produced in the prototypes help to formulate possible cleaning recipes.

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ITER光学诊断中首个镜面等离子体清洗系统的真空射频电路性能研究与比较

在许多ITER光学诊断的集合光学中，第一反射镜对光学系统的稳定运行起着至关重要的作用。为了保持镜子稳定的使用寿命，利用本地产生的射频放电的离子通量，开发了周期性的原位等离子体清洁。为了使功率有效地传输到真空等离子体负载，开发了新的阻抗匹配电路，安装在第一面镜子后面。在ITER的两个大型诊断系统（可见光谱参考系统和边缘汤姆逊散射系统）上实现了两个新的阻抗匹配原型。由陶瓷板和金属层组成的原型匹配电路在40 MHz下以100-800 W的功率在面包板上进行测试，代表两个系统的第一个镜像单元，以清洁钨模型污染物。提出了频率调谐作为降低反射功率的终身措施。在原型中产生的氩和氦等离子体的溅射结果有助于制定可能的清洁配方。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Fusion Engineering and Design 工程技术-核科学技术

CiteScore

3.50

自引率

23.50%

发文量

275

审稿时长

3.8 months

期刊介绍： The journal accepts papers about experiments (both plasma and technology), theory, models, methods, and designs in areas relating to technology, engineering, and applied science aspects of magnetic and inertial fusion energy. Specific areas of interest include: MFE and IFE design studies for experiments and reactors; fusion nuclear technologies and materials, including blankets and shields; analysis of reactor plasmas; plasma heating, fuelling, and vacuum systems; drivers, targets, and special technologies for IFE, controls and diagnostics; fuel cycle analysis and tritium reprocessing and handling; operations and remote maintenance of reactors; safety, decommissioning, and waste management; economic and environmental analysis of components and systems.