Compact pnCCD-Based X-ray Camera with High Spatial and Energy Resolution: A Color X-ray Camera

Abstract

For many applications there is a requirement for nondestructive analytical investigation of the elemental distribution in a sample. With the improvement of X-ray optics and spectroscopic X-ray imagers, full field X-ray fluorescence (FF-XRF) methods are feasible. A new device for high-resolution X-ray imaging, an energy and spatial resolving X-ray camera, is presented. The basic idea behind this so-called "color X-ray camera" (CXC) is to combine an energy dispersive array detector for X-rays, in this case a pnCCD, with polycapillary optics. Imaging is achieved using multiframe recording of the energy and the point of impact of single photons. The camera was tested using a laboratory 30 μm microfocus X-ray tube and synchrotron radiation from BESSY II at the BAMline facility. These experiments demonstrate the suitability of the camera for X-ray fluorescence analytics. The camera simultaneously records 69,696 spectra with an energy resolution of 152 eV for manganese K(α) with a spatial resolution of 50 μm over an imaging area of 12.7 × 12.7 mm(2). It is sensitive to photons in the energy region between 3 and 40 keV, limited by a 50 μm beryllium window, and the sensitive thickness of 450 μm of the chip. Online preview of the sample is possible as the software updates the sums of the counts for certain energy channel ranges during the measurement and displays 2-D false-color maps as well as spectra of selected regions. The complete data cube of 264 × 264 spectra is saved for further qualitative and quantitative processing.

Examples of XRF and PIXE imaging with few microns resolution using SLcam® a color X‐ray camera

“…r -a color X-ray camera SLcam r 's descriptive name 'Color X-ray Camera' is based on the fact that the device gives information not only on the signal intensity (brightness), but, similarly to color camera working in visible light, also on the energy of photons [6,7] . Accordingly, a color picture can be obtained by assigning different hues to different X-ray energies.…”

“…Single photon counting allows determination of the energy and position of a photon while X-ray guiding provides gathering and transfer of X-ray photons preserving the spatial information. A dedicated software enables steering the camera and real time visualization of the hyper-spectral data cube (x, y, E) by displaying regional spectra, intensity maps of X-rays of chosen energies, and overlay images [6] .…”

“…In both cases, the source location and sample-camera distance and position were optimized for the best count rates and lowest image distortion. A detailed description of both setups can be found in [6] and [15] . An example arrangement of the laboratory setup is shown in Figure 1.…”

2D and 3D Imaging of Li-Ion Battery Materials Using Synchrotron Radiation Sources

“…1:8). In case of 1:1 optics allow the acquisition of about 50 µm spatially resolved full energy spectra of an 12.7 × 12.7 mm 2 area [26,27]. From a set-up as sketched in Fig.…”

Fluorescent X-Ray Imaging With Pinhole Camera

“…При этом в качестве объектива может быть ис-пользована пинхол камера. Так, в работах [8][9][10] описаны рентгеновские устройства на основе пинхол камеры, позволяющие получать инфор-мацию о пространственном распределении хими-ческих элементов на поверхности образца с про-странственным разрешением от 30 мкм при поле зрения 2,5 × 2,5 мм 2 до 140 мкм при поле зрения 4 × 4 см 2 [9]. В качестве приемных устройств ис-пользовались энергодисперсионные цифровые двумерные ПЗС камеры.…”