Thin film based scintillators for hard X-ray microimaging detectors: the Scin TAX project A. Rack* a , A. Cecilia b , P.-A. Douissard a , K. Dupré c , V. Wesemann c , T. Baumbach b , M. Couchaud d , X. Rochet e , M. Radtke f , H. Riesemeier f , T. Martin a a European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France; b Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation / ANKA, Pf. 3640, 76021 Karlsruhe, Germany; c FEE GmbH, Struthstr. 2, 55743 Idar-Oberstein, Germany; d CEA/LETI, 38054 Grenoble Cedex, France; e Optique Peter, Allée Romaine, ZA du Charpenay, 69210 Lentilly, France. f Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 80, 12205 Berlin, Germany ABSTRACT The project Scin TAX developed novel thin scintillating films for the application in high performance X-ray imaging and subsequent introduced new X-ray detectors to the market. To achieve this aim lutetium orthosilicate (LSO) scintillators doped with different activators were grown successfully by liquid phase epitaxy. The high density of LSO (7.4 g/cm 3 ), the effective atomic number (65.2) and the high light yield make this scintillator highly applicable for indirect X-ray detection in which the ionizing radiation is converted into visible light and then registered by a digital detector. A modular indirect detection system has been developed to fully exploit the potential of this thin film scintillator for radiographic and tomographic imaging. The system is compatible for high-resolution imaging with moderate dose as well as adaptable to intense high-dose applications where radiation hard microimaging detectors are required. This proceedings article shall review the achieved performances and technical details on this high-resolution detector system which is now available. A selected example application demonstrates the great potential of the optimized detector system for hard X-ray microimaging, i.e. either to improve image contrast due to the availability of efficient thin crystal films or to reduce the dose to the sample. Keywords: indirect detection, scintillator, synchrotron radiation, LSO, thin film, liquid phase epitaxy, X-ray imaging, microtomography 1. INTRODUCTION The first indirect detection schemes were reported in the 1970s to perform so-called live topography 1 . Here, a scintillator screen converts the X-rays into visible light while the corresponding luminescence image is captured by a camera via visible light optics. Indirect detectors allow one to reach for high spatial resolution while being rather radiation hard as all electronic components can be kept out of the X-ray beam path when periscope-like designs are used. The latter commonly employ a mirror between the scintillator and the objective to form a folded optical beam path. The spatial resolution reachable is directly connected with the numerical aperture (NA) of the front objective and the wavelength of maximum emission of the scintillator screen by the Abbe diffraction limit. While high numerical apertures are required for spatial resolutions up to the (sub-)micrometer range the correspondingly reduced depth of field of the objectives limits the scintillator thickness and hence the detectors efficiency 2 . This can lead to rather long exposure times especially when laboratory-based sources are used. Consequently the success story of high-resolution indirect X-ray imaging detectors is closely related to the third generation synchrotron light sources starting their operation. Especially in combination with microtomography indirect detectors are an essential tool which allows for the technique to be used nowadays at synchrotron light sources in a routinely manner 3 . Another advantage of indirect detectors is that they consist mostly of components which are widely commercially available such as microscope objectives and CCD cameras. Therefore the technically developments in the past years already reached a high level of maturity 4 . For the sake of completeness it needs to be mentioned that X-ray topography in combination with synchrotron light sources is highly benefitted from these developments as well which allows for example real time semiconductor wafer metrology in situ under high temperature 5,6 . *arack@snafu.de; phone +33 476 88-1781; fax +33 476 88-2785; www.esrf.eu Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVI, edited by Arnold Burger, Larry Franks, Ralph B. James, Michael Fiederle, Proc. of SPIE Vol. 9213, 921312 © 2014 SPIE · CCC code: 0277-786X/14/$18 · doi: 10.1117/12.2060599 Proc. of SPIE Vol. 9213 921312-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 09/11/2014 Terms of Use: http://spiedl.org/terms