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

摘要

ABSTRACT: For many applications there is a requirement for nondestructive analyticalninvestigation of the elemental distribution in a sample. With the improvement of X-ray opticsnand spectroscopic X-ray imagers, full field X-ray fluorescence (FF-XRF) methods are feasible. Annew device for high-resolution X-ray imaging, an energy and spatial resolving X-ray camera, isnpresented. The basic idea behind this so-called “color X-ray camera” (CXC) is to combine annenergy dispersive array detector for X-rays, in this case a pnCCD, with polycapillary optics.nImaging is achieved using multiframe recording of the energy and the point of impact of singlenphotons. The camera was tested using a laboratory 30 μmmicrofocus X-ray tube and synchrotronnradiation fromBESSY II at the BAMline facility. These experiments demonstrate the suitability ofnthe camera for X-ray fluorescence analytics. The camera simultaneously records 69 696 spectranwith an energy resolution of 152 eV formanganese KR with a spatial resolution of 50 μmover an imaging area of 12.7u000112.7mm2n.Itnis sensitive to photons in the energy region between 3 and 40 keV, limited by a 50 μmberylliumwindow, and the sensitive thicknessnof 450 μm of the chip. Online preview of the sample is possible as the software updates the sums of the counts for certain energynchannel ranges during the measurement and displays 2-D false-color maps as well as spectra of selected regions. The complete datancube of 264 u0001 264 spectra is saved for further qualitative and quantitative processing.