Upgrade of an existing 3D X-ray microscope

德累斯顿纳米分析中心(DCN)目前拥有一台显微镜。该仪器有第二个光光放大平台，可以几乎不依赖于样本大小来生成高分辨率图像。在传统的锥束X射线层析成像(Micro X-ray CT)设备中，像素化X射线探测器只有几何放大率，最小的合理分辨率部分受光源焦斑的限制，部分受探测器像素大小的限制。在具有两级放大的设备中，一方面通过减小有效像素大小，另一方面通过减小几何放大倍数，也可以在焦斑直径以下成像。这种更精细的扫描还允许通过传播相位对比度进行成像，这会导致对比度显著提高，特别是对于原子序数较低的样品，因此吸收也较低。由于对(白)X射线光的相干性的要求以及在低X射线能量下性能的限制，这些测量通常需要很长的测量时间。在本申请中，要求对系统进行升级，其关键特征包括强度提高2.5倍的X射线源、远低于1μm的分辨率特性，同时保持高加速电压。这一方面允许成像具有更高的信噪比，另一方面允许成像比以前更大的样本区域。

The Dresden Center for Nanoanalysis (DCN) currently houses a microscope. The instrument has a second, light-optical magnification stage, which allows high-resolution images to be produced almost independently of the sample size. In a conventional micro X-ray tomography (micro X-ray CT) apparatus with a cone beam and only geometric magnification on a pixelated X-ray detector, the smallest reasonable resolution is limited partly by the focal spot of the source and partly by the pixel size of the detector. In devices with two-stage magnification, on the one hand, by reducing the effective pixel size, and on the other hand, by reducing the geometric magnification, imaging below the focal spot diameter is also possible. This finer scanning also allows imaging by means of propagation phase contrast, which leads to significantly higher contrast, especially for samples of low atomic number, and thus low absorption. Due to the requirements on the coherence of the (white) X-ray light as well as the limitation of the performance at low X-ray energies, these measurements usually require long measurement times. In the present application, an upgrade for the system is requested, which includes as key features a 2.5-fold stronger X-ray source, improved resolution properties of well below 1 μm while maintaining a high accelerating voltage. This allows imaging with an increased signal-to-noise ratio on the one hand, and imaging of larger sample areas than before on the other.