System and method for mapping chemical elements in a sample

A method for determining spatial distribution of chemical elements in a sample, the method comprising:

• providing predetermined modulation encoding data comprising two or more predetermined spatial intensity patterns of primary radiation, comprising x-ray spectral ranges, each corresponding to the primary radiation encoded by respective two or more different spatial transmission functions;
• performing a plurality of spectral measurements on the sample including a sequence of two or more spectral measurements comprising:
• exciting the sample with said primary radiation encoded by said two or more different spatial transmission functions, respectively, and having spectral characteristic adapted to excite a number M(M≥1) of chemical elements in the sample to induce M respective secondary radiation responses, respectively, from the sample, detecting the secondary radiation responses and generating spectral measured data comprising two or more measured spectral data pieces indicative of two or more secondary radiation responses from the sample, each being characterized by sparsity in spectral domain with respect to each spectral component of the secondary radiation response and being modulated by the respective one of the two or more predetermined characteristic spatial intensity patterns of the encoded primary radiation;
• and
• analyzing the spectral measured data and determining data indicative of spatial distribution of said M chemical elements in the sample, said analyzing of the measured spectral data comprising:
• utilizing the modulation encoding data indicative of said sequence of the two or more predetermined spatial intensity patterns used in measurements on the sample and applying compressed sensing processing to the spectral measured data to determine correlation data describing correlation between each of the spectral measured data pieces and the respective predetermined spatial intensity pattern of the encoded primary radiation, and extract, from the correlation data, location data where each spectral component of the detected secondary responses is originated in the sample, and utilizing reference spectral data indicative of secondary radiation responses of the M chemical elements associating the location data of origination of the spectral components of the detected secondary responses with the respective M chemical elements, and reconstructing map data indicative of spatial distribution of each of the M chemical elements in the sample.

A control system for use in determining spatial distribution of chemical elements in a sample, the control system comprising a computer system comprising data input and output interface, a memory utility, and a data processor, and being in data communication with a measurement system providing measured data comprising two or more measured spectral data pieces indicative of two or more detected secondary radiation responses of a sample modulated by respective two or more predetermined spatial intensity patterns of encoded primary radiation of x-ray and/or gamma-ray spectral ranges and characterized by sparsity in spectral domain with respect to each spectral component of the secondary radiation response, the data processor being configured and operable to receive and analyze said measured data and determine spatial distribution of M chemical elements in the sample, the analysis of the measured data comprising:

• utilizing modulation encoding data indicative of the predetermined spatial intensity pattern of the primary radiation and applying compressed sensing processing to the measured spectral data to determine correlation data describing correlation between each of the spectral measured data pieces and the respective predetermined spatial intensity pattern of the encoded primary radiation, and extract, from the correlation data, location data where each spectral component of the detected secondary responses is originated in the sample, and utilizing reference spectral data indicative of secondary radiation responses of the predetermined M chemical elements and associating the location data of origination of the spectral components of the detected secondary responses with the respective M chemical elements, and reconstructing map data indicative of spatial distribution of each of the M chemical elements in the sample.