An upgraded detector and several optimizations have significantly improved the Ultra-Fast Charge Exchange Recombination Spectroscopy (UF-CHERS) diagnostic sensitivity to ion temperature and parallel velocity fluctuations at turbulence relevant spatio-temporal scales. Normalized broadband ion temperature and parallel velocity fluctuations down to $\tilde{x}x\sim 1\%$ (x = T_i, v_∥) and up to ∼450 kHz have been measured in a variety of plasmas. The multi-field nature of the CHERS technique also allows measurements of the cross-phase angles of the fluctuating fields. UF-CHERS is optimized to observe emissions from the electron exchange reaction between intrinsic C⁶⁺ and hydrogenic neutral beam injected particles near 529 nm. UF-CHERS consists of two chords separated by ∼1 cm radially, less than the turbulence correlation length in DIII-D plasmas, which enables correlated measurements to suppress incoherent electronic and photon noise. The optical components of the spectrometer include a volume-phase-holographic grating with >90% transmission between 528 and 530 nm and f/2 200-mm lenses, selected to maximize the optical efficiency and photon flux. Diffracted light from each chord is collected in eight spectral bins, each with a bandwidth of ∼0.25 nm, and detected and amplified by chilled avalanche photodiodes and custom high-gain, wide bandwidth low-noise preamplifiers to achieve the optimal signal-to-noise ratio. The resulting signals are digitized at 1 MHz, 10³–10⁴× faster than the conventional CHERS diagnostics. Spatial coverage is achieved by repositioning a motorized fiber tray between plasmas. UF-CHERS measurements will advance the understanding of turbulent ion transport and contribute to the validation of transport models and simulations.

中文翻译：

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使用 DIII-D 托卡马克中的超快电荷交换复合光谱 (UF-CHERS) 测量离子温度和旋转波动

升级后的检测器和多项优化显着提高了超快速电荷交换重组光谱 (UF-CHERS) 对离子温度和湍流相关时空尺度上的平行速度波动的诊断灵敏度。归一化宽带离子温度和平行速度波动低至$\tilde{X}X～1\%$( x = T _i , v _∥ ) 和高达 ~450 kHz 的频率已经在各种等离子体中被测量到。CHERS 技术的多场特性还允许测量波动场的交叉相位角。UF-CHERS 被优化用于观察本征 C ⁶⁺和氢中性束注入粒子之间的电子交换反应在529 nm 附近的发射。UF-CHERS 由两个径向分隔约 1 cm 的弦组成，小于 DIII-D 等离子体中的湍流相关长度，这使得相关测量能够抑制非相干电子和光子噪声。光谱仪的光学组件包括一个体积相全息光栅，其在528和530 nm之间的透射率> 90％，并且f /2 200 毫米镜头，选择以最大限度地提高光学效率和光子通量。来自每个弦的衍射光被收集在八个光谱箱中，每个光谱箱的带宽约为0.25 nm，并通过冷冻的雪崩光电二极管和定制的高增益，宽带低噪声前置放大器进行检测和放大，以实现最佳的信噪比比率。结果信号以 1 MHz 的频率进行数字化，比传统的 CHERS 诊断快10 ³ –10 ⁴倍。通过在等离子体之间重新定位电动纤维托盘来实现空间覆盖。UF-CHERS 测量将促进对湍流离子输运的理解，并有助于输运模型和模拟的验证。