To be able to perform a two-dimensional study of free radical distribution by the continuous-wave electron paramagnetic resonance method in the X-band, special coils producing a magnetic gradient of 8 G/mm have been designed and construeted. The EPR spectra recorded for this gradient were subjected to the procedure of deconvolution in order to elieit information on the concentration of the radical distribution. The data obtained were used as the souree file of the program reconstructing the image. The reconstruction was based on the iterative simultaneous algebraic reeonstruction teehnique (Andersen A.H., Kak A.C.: Ultrason. lmag. 6, 81-94, 1984). The quality of the generated images depends on the angle of the sample axis to the gradient direction set by a goniometer and on the deconvolution procedures applied. The first tests on artificially generated phantoms indicated a dependence of the obtained images on the magnetic field gradients apptied. The determined spatial distribution of radicals has confirmed their uniform distribution in the sample. The preliminary tests were performed for diphenyl-picrylhydrazyl. Having proved the reliability of the method, analogous measurements were also performed for plyphenylene sulphide PPS-V1 and indicated a homogeneous distribution of radicals in the whole volume of the sample. The images obtained confirmed the uniforro distribution of the radicals.
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