High power electron generators based on charging of a pulse-forming line by means of electrically exploded wires

Most of the currently operating high-power megampere generators have been developed in one of two circuit designs. In the former case, the generator consists of a high-operating-voltage (HV) microsecond Marx generator (U > 1.5 – 2 MV), several cascades of water pulse-forming lines (FL) , a transmission line, and a vacuum diode. In the latter case, these are a rather low-operating-voltage (LV) microsecond Marx (U < 1 MV), an inductive energy store, a POS, and a proper diode. Each of these circuit designs has certain deficiencies. In the former case, these are the well-known operating difficulties with the HV Marx (more stringent requirements the insulation and the bulky element base), and the presence of bulky microsecond FLs with their provision systems, that increase the installation size. In the latter case, these are a rather low switch resistance at the stage of current switching into a load, hence, a slightly increased output voltage and, particularly, power. At the same time, there exist well-known low-current high-power HV e-beam generators, which are built in the circuit design including a LV (∼ 1 MV) microsecond Marx, an inductive energy store, an exploding wire (EW) switch, and a vacuum diode. In such generators, the above mentioned problems are solved by increasing the initial voltage four to six times. But these circuits have a low energy efficiency (< 30 %) related to the EW operation into a resistive load (diode). However, it can be supposed that a capacitive load, because of its specific impedance, may have a higher energy efficiency for the same maximum voltages. Thereby, we consider the operation of the high-power high-current generator (HPHCG) with the circuit design “LV Marx - inductive storage - EW switch - fast FL - transmission line - diode”. Here the main problem is the efficiency of energy transfer from the Marx to the HV-FL. Some relevant information is in Refs. 1 and 2.