Ion-Focused Propagation of Relativistic Electron Beam in the Self-Generated Plasma in the Atmosphere

It is known that ion-focused regime can effectively suppress the expansion of relativistic electron beam (REB). By using particle in cell-Monte Carlo collision (PIC-MCC) method, the propagation of REBs in neutral gas is numerically investigated. The numerical results demonstrate that the beam body is charge neutralization and a stable IFR can be established. As a result, the beam transverse dimensions and longitudinal velocities keep close to the initial parameters. We also calculated the charge and current neutralization factors of REBs. Combined with envelope equations, we obtained the variations of beam envelopes, which agree well with the PIC simulations. However, both the energy loss and instabilities of REBs may lead to a low transport efficiency during long-range propagation. It has been proved that decreasing the initial pulse length of REBs can avoid the influence of electron avalanche. Using parts of REB pulses to build a long-distance IFR in advance can improve the beam quality of subsequent pulses. Further, a long-distance IFR may contribute to the implementation of long-range propagation of REBs in the space environment.

Effect of Structural and Phase Changes under Relativistic Electron Pulsed Beam Irradiation on the Aluminum Alloys Micro-hardness

The paper studies the distinctive features of micro-hardness value changes in the zone of industrial aluminum alloy 1933 and alloy 1380 irradiated by the relativistic electron beam. The surface layer was modified under the relativistic electron beam injected along with the equal energy parameters. However, we have to claim that some physical and technological properties of the irradiated alloys layer came with some differences. The modified layer micro-hardness increased over 30% in 1933 aluminum alloy and decreased by 10% in 1380 aluminum alloy. The mechanisms affecting the metal material strengthening transformation after a pulsed electron beam application are analyzed. Thus it was established that one of the core impacts to increase the micro-hardness of 1933 aluminum alloy surface layer was fine MgO impurities being absent in the initial alloy and caused by the irradiation, whilst the micro-hardness of the irradiated layer of the 1380 aluminum alloy decreases due to the dissolution during irradiation of the strengthening phases, which were identified in the initial state.

HIGH-CURRENT RELATIVISTIC ELECTRON BEAM FOCUSING IN PLASMA

The analysis of the envelope equation for high-current relativistic electron beam propagation in plasma in an external uniform magnetic field is presented. The envelope equation is obtained in a Hamiltonian form with an effective potential, which depends from electron beam and plasma parameters, and external magnetic field. Hamiltonian aproach allows fully analyze the behavior of the beam envelope as a function of the beam current, beam energy, plasma density and conductivity, as well as on the external magnetic field and the initial beam angular momentum.

TRIGGERING PULSE GENERATORS DEVELOPED FOR THE HIGH-VOLTAGE DISCHARGERS OF MAGNETIC SYSTEMS AND FOR THE GENERATOR OF PULSE VOLTAGES USED BY THE RELATIVISTIC ELECTRON BEAM ACCELERATOR “TEMP-B”

The pulse generators were developed to trigger the high-voltage dischargers of magnetic systems and the dischargers of the generators of pulsed voltages used by the relativistic electron beam (REB) accelerator “TEMP-B”. The description of the triggering pulse generators designed by the NSC KIPT to actuate the dischargers of the pulsed voltage generators (PVG) and the dischargers of magnetic systems has been given. These are used by the commutation systems of capacitor banks with the stored energy margin in the range of 60 to 150 kJ. The generators provide the generation of voltage pulses with the amplitude of up to 20 kV.