A new pnCCD-based color X-ray camera for fast spatial and energy-resolved measurements

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2011-10, Vol.654 (1), p.250-257
• Main Authors: Ordavo, I., Ihle, S., Arkadiev, V., Scharf, O., Soltau, H., Bjeoumikhov, A., Bjeoumikhova, S., Buzanich, G., Gubzhokov, R., Günther, A., Hartmann, R., Holl, P., Kimmel, N., Kühbacher, M., Lang, M., Langhoff, N., Liebel, A., Radtke, M., Reinholz, U., Riesemeier, H., Schaller, G., Schopper, F., Strüder, L., Thamm, C., Wedell, R.
• Format: Article
• Language: English
• Subjects: Cameras; Color; Detectors; Elemental analysis; Fast X-ray imaging; Fluorescence; Frames; Full-field X-ray fluorescence; High energy resolution; High quantum efficiency; Photons; pnCCD; Polycapillary optics; Quantum efficiency; X-ray CCD camera; X-rays; XRF
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2011.05.080

We present a new high resolution X-ray imager based on a pnCCD detector and a polycapillary optics. The properties of the pnCCD like high quantum efficiency, high energy resolution and radiation hardness are maintained, while color corrected polycapillary lenses are used to direct the fluorescence photons from every spot on a sample to a corresponding pixel on the detector. The camera is sensitive to photons from 3 to 40 keV with still 30% quantum efficiency at 20 keV. The pnCCD is operated in split frame mode allowing a high frame rate of 400 Hz with an energy resolution of 152 eV for Mn K α (5.9 keV) at 450 kcps. In single-photon counting mode (SPC), the time, energy and position of every fluorescence photon is recorded for every frame. A dedicated software enables the visualization of the elements distribution in real time without the need of post-processing the data. A description of the key components including detector, X-ray optics and camera is given. First experiments show the capability of the camera to perform fast full-field X-Ray Fluorescence (FF-XRF) for element analysis. The imaging performance with a magnifying optics (3×) has also been successfully tested.