The Arcus Probe mission concept has been submitted as an Astrophysics Probe Explorer candidate. It features two co-aligned high-resolution grating spectrometers: one for the soft X-ray band and one for the far ultraviolet. Together, these instruments can provide unprecedented performance to address important key questions about the structure and dynamics of our universe across a large range of length scales. The X-ray spectrometer consists of four parallel optical channels, each featuring an X-ray telescope with a fixed array of 216 lightweight, high-efficiency, blazed transmission gratings, and two charge-coupled device readout arrays. Average spectral resolving power λ/Δλ>2500 (3500 expected) across the 12 to 50 Å band and combined effective area >350 cm2 (>470 cm2 expected) near OVII wavelengths are predicted, based on the measured X-ray performance of the spectrometer prototypes and detailed ray trace modeling. We describe the optical and structural design of the grating arrays, from the macroscopic grating petals to the nanoscale gratings bars, grating fabrication, alignment, and X-ray testing. Recent X-ray diffraction efficiency results from chemically thinned grating bars are presented and show performance above mission assumptions.

中文翻译：

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Arcus 探针上 X 射线光谱仪的透射光栅阵列


Arcus 探测器任务概念已作为天体物理探测器探测器候选项目提交。它具有两台并排的高分辨率光栅光谱仪：一台用于软 X 射线波段，一台用于远紫外线。这些仪器可以提供前所未有的性能，以解决有关大范围长度尺度上的宇宙结构和动力学的重要关键问题。 X 射线光谱仪由四个并行光学通道组成，每个通道均配有一个 X 射线望远镜，该望远镜具有 216 个轻质、高效、闪耀传输光栅的固定阵列，以及两个电荷耦合器件读出阵列。根据光谱仪测得的 X 射线性能，预测 12 至 50 Å 波段的平均光谱分辨率 λ/Δλ>2500（预计 3500）以及 OVII 波长附近的组合有效面积 >350 cm2（预计 >470 cm2）原型和详细的光线追踪建模。我们描述了光栅阵列的光学和结构设计，从宏观光栅瓣到纳米级光栅条、光栅制造、对准和 X 射线测试。最新的化学减薄光栅条的 X 射线衍射效率结果被呈现，并显示出高于任务假设的性能。