Repetitive nanosecond electron accelerators type URT-1 for radiation technology

Abstract

The electron accelerator URT-1М-300 for mobile installation was created for radiation disinfecting to correct drawbacks that were found the URT-1M electron accelerator operation (the accelerating voltage up to 1 МV, repetition rate up to 300 pps, electron beam size 400 × 100mm, the pulse width about 100ns). Accelerator configuration was changed that allowed to reduce significantly by 20% tank volume with oil where is placed the system of formation high-voltage pulses, thus the average power of the accelerator is increased by 6 times at the expense of increase in pulses repetition rate. Was created the system of the computerized monitoring parameters (output parameters and thermal mode) and remote control of the accelerator (charge voltage, pulse repetition rate), its elements and auxiliary systems (heat of the thyratron, vacuum system), the remote control panel is connected to the installation by the fiber-optical channel, what lightens the work for service personnel. For generating an electron beam up to 400mm wide there are used metal- ceramic] and metal-dielectric cold cathodes of several emission elements (plates) with a non-uniform distribution of the electron beam current density on the output foil ± 15%. It was found that emission drop of both type of cathodes, during the operation at the high repetition rate (100pps) is substantial at the beginning of the process, and then proceeds rather slowly that allows for continuous operation up to 40h. Experiments showed that linear dependence of the voltage and a signal from the pin-diode remains within the range of the charge voltage 45–65kV. Thus, voltage increases from 690 to 950kV, and the signal from the pin-diode – from (2,8–4,6)*104Gy/s. It allows to select electron energy quite precisely with consideration of the radiation technology requirements.