Doppler reflectometry is an important microwave diagnostic for turbulent fusion plasmas. A microwave beam is scattered off density fluctuations, with wavenumbers according to incident frequency and relative direction. This way, a density fluctuation spectrum is measured. However, the correspondence between fluctuation power and scattered microwave power is strongly nonlinear. Studying these processes numerically therefore requires fullwave simulations (IPF-FD3D), with density fluctuations supplied by a separate plasma turbulence code (GENE). Earlier such attempts suffered from the low number of data points in the ‘interesting’ part of the spectrum, where a power law had to be fitted to 4 or 5 points. This has been overcome with recent simulations, which now show a much better agreement with experimental data.

中文翻译：

---

使用GENE和IPF-FD3D在ASDEX升级中对密度湍流谱进行全波多普勒反射模拟

多普勒反射仪是湍流聚变等离子体的重要微波诊断方法。微波束被密度波动散射，波数根据入射频率和相对方向而变化。这样，测量了密度波动谱。然而，波动功率和散射微波功率之间的对应关系是强烈非线性的。因此，从数字上研究这些过程需要全波模拟（IPF-FD3D），密度波动由单独的等离子体湍流代码（GENE）提供。早些时候，此类尝试受到频谱“有趣”部分中数据点数量少的困扰，在该部分中，幂律必须适合4或5个点。最近的仿真已经克服了这一问题，现在的仿真显示与实验数据的一致性更好。