Standardization of X-ray sources below 4 keV

Methods for fibrication and standardization of compact calibration radiation sources below 4 keV with the accuracy of the order of 3% are described. The design of the sources presupposes initiation of x radiation in foils made of elements for chemical compounds with low Z number using excitation of K-shell fluorescence under the effect of x radiation (>5 keV) emitted by corresponding radionuclide. The aluminium source emitting 1.49 keV x radiation (K-line) is considered as an example. The source calibration is performed by means of a proportional gas-flow counter with common configuration having precise collimation and thin window . Based on the results of measuring radiation anisotropy of the considered source it is concluded that through the described low-energy sources can be accurately standardized the solution of the problem of their applicability depends on space and rotation angles for which measurements are made