Results of numerical simulation of electron dynamics in a non-homogeneous disk-loaded waveguide which is used in the S-band linac with average power of an accelerated beam of 10 kW are presented. Two approaches taking into account the self-fields of beam radiation are considered: the first method, the estimative one, based on the power diffusion equation; the second, the full-scale one, based on self-consistent equations of field excitation and particles motion. The self-consistent approach showed the presence of substantial phase slipping of particles in the homogeneous part of the rf structure, conditioned by the reactive beam loading.

The industrial radiation plant on the base of electron Linac LU-10 (10 MeV, 10 kW) was developed and put into operation in 1987. At present Linac LU-10 provides a principal bulk of activity on radiation sterilization in Ukraine. The system of metrological maintenance including a set of technological measuring channels as well as a complex of working standards was created side by side with continuous modernization of the plant. These facilities allow conducting both industrial treatment of the product and its qualification tests using electron and bremsstrahlung radiation. Principal plant radiation parameters as well as used measurement instrumentation and computer technologies are described in the report. The data on dynamics of service volume in the field of radiation processing at the plant for last years are represented.

The report contains the review of electron linac research and development activity at the National Science Center "Kharkov Institute of Physics and Technology". The main results on the research of electron sources (RF guns, secondary emission guns), injector systems, accelerating structures are presented. The report also presents descriptions of some applications of designed linacs.

LU-10 single-section electron Linac was commissioned in 1987 [1]. Up to mid 1993 it had operated on KIU-53 klystron, producing electron beam with output energy within the maximum power spectrum Ej max ≅10 MeV and average current Iav≅500 μa at a rep rate N=150 1/ sec. A necessity arose in 1993 to increase beam energy and output power. However, by this time KIU-53 klystrons were no longer produced by industry with only KIU-12 klystrons being available for this purpose. Since KIU-12 has the pulsed power operation value Ppul≅(20÷18)MW at N≅(50÷100) 1/sec, respectively, then, it was necessary that N be raised up to 300 s-1 with increasing Ppul up to (24÷26)MW, the decision was taken to upgrade the rf-power input source for the LU-10 accelerating section and employ in the new LU-10M a scheme of adding up the rf-power output from both KIU-12 klystrons. The earlier studies [2] gave a reason to believe that such a set-up should provide for a reliable operation of the accelerator and required beam parameters at N=300 1/sec and the power input operation Ppul≅(12÷13)MW from each of the two KIU-

The dynamics of stimulated Brillouin scattering in a parametric oscillator with feedback is studied taking into account all possible refractive index gratings. It is shown that under certain conditions the excitation of an additional transmission grating does not impede efficient generation of a phase-conjugated light wave.

An accelerating section with varying cross section and 2..pi../3 working oscillation phase has been designed, built, and tested. The experimental results at low powers and in the acceleration mode are in satisfactory agreement with calculated results.

Impact resistant all-poly(lactic acid) composites were prepared by film-stacking of highly crystalline poly(lactic acid) (PLA) fibres with fully amorphous PLA films. The flammability of the self-reinforced PLA composites (PLA-SRCs) was effectively reduced by incorporating ammonium polyphosphate based flame retardant (FR) additive and montmorillonite clays in a weight ratio of 10 to 1 into the matrix layers. As low as 16 wt% FR content proved to be sufficient for achieving self-extinguishing behaviour, i.e. UL94 V-0 rating, and to achieve 50% and 40% reduction of peak of heat release rate and total heat emission, respectively. The introduction of FR additives improved also important mechanical properties compared to the FR-free all-PLA composite. The stiffness of the PLA-SRCs increased steadily with the FR contents of their matrix layers, furthermore, owing to the improved fibre–matrix bonding, prominent energy absorption capacity (impact perforation energy as high as 16 J/mm) was determined for the effectively flame retarded PLA-SRC.

An installation is described for the investigation of superconducting resonators for the 10-cm range in powerful microwave fields. Data are presented on a superconducting resonator with a lead galvanic coating at an amplitude of the axial high-frequency electric field ranging up to 100 kV/cm. (auth)