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。该仪器具有第二个光学放大级，它允许几乎独立于样品大小产生高分辨率图像。在具有锥形束并且在像素化X射线检测器上仅具有几何放大的常规微型X射线断层摄影（微型X射线CT）设备中，最小合理分辨率部分地受到源的焦斑的限制并且部分地受到检测器的像素尺寸的限制。在具有两级放大率的设备中，一方面通过减小有效像素尺寸，另一方面通过减小几何放大率，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的方式成像，这导致显著更高的对比度，特别是对于低原子序数的样品，从而导致低吸收。由于对（白色）X射线光的相干性的要求以及在低X射线能量下的性能的限制，这些测量通常需要长的测量时间。在本申请中，要求对系统进行升级，其包括作为关键特征的2.5倍更强的X射线源、远低于1 μ m的改进的分辨率特性，同时保持高加速电压。这一方面允许以增加的信噪比成像，另一方面允许比以前更大的样品区域的成像。

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.