电压控制振荡器 (VCO) 的频率线性化用于2μs频率调制连续波 (FMCW) 反射计
1Korea Institute of Fusion Energy, Daejeon 34133, South Korea.
The Review of scientific instruments
|October 21, 2024
概括
这项研究开发了一个更快的频率调制 (FM) 驱动器用于KSTAR反射计. 新系统将FM时间缩短到2μs,改善了聚变装置中的等离子体密度配置测量.
科学领域:
- 血物理学的等离子体物理学
- 核聚变能源的研究.
- 诊断技术 诊断技术 诊断技术
背景情况:
- 频率调制连续波 (FMCW) 反射计对于测量磁聚变装置中的等离子体密度概况至关重要.
- 现有的KSTAR反射计系统具有20μs频率调制 (FM) 时间与ELMy H模式等离子体中的高频边缘密度波动 (20-50 kHz) 相斗争.
- 这些波动会导致密度谱测量的显著扭曲,原因是FM时间发生的变化.
研究的目的:
- 为了解决当前FMCW反射仪在准确测量快速变化的等离子体边缘密度方面的局限性.
- 设计和实施一个新的电压控制振荡器 (VCO) 驱动器,能够实现显著减少FM时间.
- 开发一种有效的频率线性化方法,以提高等离子体密度概况诊断的准确性.
主要方法:
- 使用AD8067操作放大器设计了一个新的VCO驱动器,以实现2μs FM时间.
- 通过预扭曲VCO调电压以400MSamples/s任意波形发生器来实现线性频率调制.
- 通过将VCO输出与频率合成器混合并使用2.5 GSamples/s数字化器分析中间频率来测量输出频率.
- 一个反循环调整了调电压,以尽量减少频率偏差,考虑到VCO驱动器和输入接口的响应时间.
主要成果:
- 成功开发了一种新的VCO驱动器,可实现2μs FM时间.
- 采用频率线性化方法来提高密度配置测量的准确性.
- 开发的系统旨在克服由高频等离子体边缘密度波动引起的局限性.
结论:
- 开发的VCO驱动器和线性化技术显著提高了FMCW反射测量的能力,用于测量动态等离子体边缘密度.
- 这一进步对于在磁束聚变研究中精确的血形状诊断至关重要,特别是在像KSTAR这样的设备中.
- 改进的FM速率允许可靠的密度配置测量,即使在快速边缘波动的情况下.
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