The progress of X-ray fluorescence computed tomography at SSRF

X-ray fluorescence computed tomography is a stimulated emission tomography that allows nondestructive reconstruction of elements distribution in the sample and has been applied in many fields. Since 2007 we have developed X-ray fluorescence tomography for microanalysis. In 2010, the system was established at the Shanghai Synchrotron Radiation Facility (SSRF) and preliminary experimental results were obtained at the X-ray imaging (BL13W1) and hard X-ray micro-focusing beamline (BL15U1). Recently, an ordered-subsets expectation maximization algorithm has been introduced to speed up the data acquisition process. We are now studying accelerating X-ray fluorescence computed tomography based fast scanning and the new algorithm.