A novel approach to correlation reflectometry
A novel approach to correlation reflectometry
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相关反射测量的新方法
DOI：
10.1016/j.fusengdes.2011.03.013
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发表时间：
2011
影响因子：
1.7
通讯作者：
M. Manso
中科院分区：
文献类型：
--
作者：
L. Meneses;L. Cupido;M. Manso
微波合成源的使用大大提高了聚变等离子体相关反射诊断的性能，提供了宽带操作，高质量的信号和快速的频率切换时间。IPFN最近对这些光源的新开发为建立具有改进性能和测量能力的相关反射测量诊断开辟了一条全新的道路。现在可实现的一些关键特性是由分离的频率合成器产生的独立探测和本地振荡器信号;本地和射频振荡器的非常好的频率控制和同步提供非常高的稳定性。技术进步使得进一步减少相邻探测频率之间的切换时间成为可能，同时保持在宽频率范围内工作的能力。在这里，我们提出了一个多通道相关系统的基础上，这些新技术使用几个独立的和自包含的完全合成的宽带通道。利用这种类型的系统，各种类型的测量是可能的：（i）快速逐步径向扫描以提取湍流参数的径向轮廓（频谱、RMS、来自多普勒频移的旋转等）; (ii)使用并行的两个相同系统对等离子体进行径向扫描，其中一个系统以频率步进操作，而另一个系统围绕第一系统的每个选定频率进行多个小步进。所提出的诊断是非常强大和通用的。对于具有n个相同信道的系统，所有信道同时发送和接收，可以执行的同时相关测量的数量由n×（n−1）/2给出。最小配置使用两个通道，从而提供一个（时域）相关信号通道，可以在任何时候轻松添加，从而提高诊断的测量能力。给出了几个例子，说明了广泛的测量，可以使用新的方法进行相关反射诊断。
The use of microwave synthesized sources improved significantly the performance of correlation reflectometry diagnostics for fusion plasmas providing broadband operation with high quality signals and fast frequency switching times. Recent new developments of those sources made at IPFN opened an all-new way to build correlation reflectometry diagnostics with improved performance and measuring capability. Some of the key features now attainable are independent probing and local oscillator signals generated by separated frequency synthesizers; very good frequency control and synchronization of both the local and the radio-frequency oscillators providing very high stability. The technological advances make it possible to further reduce the switching time between adjacent probing frequencies while keeping the ability to operate in a broad frequency range. Here we present a multichannel correlation system based on those novel technologies using several independent and self-contained fully synthesized broadband channels. With this type of system various type of measurements are possible: (i) fast stepwise radial scans to extract the radial profile of turbulence parameters (spectra, RMS, rotation from Doppler shift, etc.); (ii) radial scans of the plasma using two identical systems in parallel where one system operates in frequency steps and the other makes multiple small steps around each selected frequency of the first system. The proposed diagnostic is very powerful and versatile. With a system having n identical channels, all transmitting and receiving simultaneously, the number of simultaneous correlations measurements that can be performed is given by n×(n−1)/2. The minimal configuration uses two channels thus providing one (time domain) correlation signal channels can be easily added at any time increasing the measuring capability of the diagnostic. Several examples are given that illustrate the wide range of measurements that can be made using the novel approach for correlation reflectometry diagnostics.