Properties of hens' eggs after surface irradiation by nanosecond electron beam

There are presented some details of the technology of surface disinfection of the fresh eggs. Irradiation experiments were carried out by means of the pulsed repetitive nanosecond accelerator URT-0.5 (electron energy of up to 500 keV, a pulse duration of 50 ns, pulse repetition rate up to 200 pps, which significantly reduce the costs of the irradiation in comparison with high-energy electrons (several MeV) or gamma-radiation. The determination of the distribution of the absorbed dose in the depth of the polyethylene was conducted by the gray wedge method. Measurement of the electron beam dose on the surface of the shell and under the shell, as well as beneath the absorber layer (polyethylene 80 mu m thick) was also performed by a film dosimeter. The electron average dose rate on the egg surface was 200 Gy/pulse and the instantaneous dose rate was 4 GGy/s. The non-uniform distribution of the electron beam current density on the output foil was +/- 15%. Thermoluminescent dosimeters, TLD-500, were used to determine the distribution of the bremsstrahlung dose inside hens' eggs. It has been established that for nanosecond electron beam irradiation with dose higher than 5 kGy sufficient for complete disinfection on the hens' egg surface, due to bremsstrahlung, the dose inside it will not exceed 8 cGy. This dose value should not lead to biological changes in the white or yolk. Dose 5 kGy does not influence the observed shell surface; there are no changes on the egg surface according to scanning electron microscope data. For heavy doses, rounded areas of the surface relief are observed. Data from energy-dispersive X-ray spectroscopy analysis for high dose show a significant increase in the amount of phosphorus and especially calcium in the shell and some reduction in the amount of oxygen, most likely due to change in the surface distribution of elements in the shell.