[en] The pulse power technology has wide ranging applications in industry, defence and research. These systems can be operated in single pulsed or repetitively pulsed mode for various applications, in the range of a few pulses per minute to a few kHz. The sparkgap is the most important and critical component in a pulse power system. The characterization of sparkgaps, types of measurements of recovery times and voltages are presented. The various single pulse and repetitively pulsed sparkgaps are reviewed and a brief review is presented here. (author)

[en] The principle schemes of pulse power electron accelerators used for (i) flash x-rays (FLX), and (ii) high power microwaves (HPW) presented in this paper. (author)

No abstract available

[en] Full text: The Linear Induction Accelerator is being constructed for research and applications of high energy beams with high repetition rate. This paper presents the status of 200 keV, 5 kA, 50 ns, 10 Hz-100 Hz Linear Induction Accelerator (LIA) project undertaken by us. The main challenges involved in this project are development of (i) high power switching modules, (ii) pulse transformer with minimal leakage inductance and (iii) magnetic switches iv) induction cavities. Our scheme starts with a low voltage high current DC system charging a capacitor followed by a chain of compression stages and voltage step-up. The 2.5kV : 20kV first stage pulse transformer with built-in reset arrangement has been designed and fabricated with 6-toroidal amorphous cores of size 160/240/25mm. The total leakage inductance could be minimized to 3.5mH. The coaxially designed next stage pulse compression module has been fabricated and tested for full ratings. Water capacitors have been designed for energy storage at subsequent microsecond time scales. Provided with demineralised water circulation and adequate mechanical support, they are currently under fabrication. A 2.5 W water pulse- forming line (PFL) with water-oil interface is also designed to realize a pulse of 50 ns duration across a matched load with minimum distortion. The PFL is connected to the three induction cavities in parallel by a single output switch and three parallel bunches of cable with 100 kV insulation ratings providing an effective characteristic impedance of 2.5 W. Prototype induction cavities using amorphous cores at 20 kV voltage level have been operated in the adder mode. The graphite field emission diode is connected at the output of the adder consisting of three 75 kV induction modules offering a reflected impedance which matches with that of the PFL

[en] In a linear induction accelerator, limitations come on operating voltage mostly due to surface flashover along the vacuum solid or oil/solid interface in the induction cavity. Present analysis, is done to study the field configurations across the insulator in vacuum and in transformer oil respectively. Poisson-code is used to see the effect of angle of spacer in the test configuration. It has been found that vacuum has more significant angle effect than in oil. Field concentration is also seen more in case of vacuum interface. (author)

No abstract available

[en] A compact Marx generator (225kV, 6kA, 100ns, 150J) has been designed and developed which is made of folded pulse forming line modules (FPFL). The FPFL gives flat top output pulse. Firstly, it was characterized with non inductive aqueous resistive load then connected to relativistic diode. This diode chamber is evacuated with online vacuum system and generated electron pulses are converted into flash X-rays by Bremsstrahlung radiation. The Marx generator has the advantages of higher peak power rating, compactness, low cost and reliability in comparison with the conventional pulse-forming network (PFN) Marx. Details of the Marx generator and FXR source are described in following sections. (author)

[en] Full text: This paper presents the design and test results of a Z-type plus -minus charging Marx generator of peak ratings 1MV and 25kJ. This is a modular design where five identical stages of Marx have been put on a trolley so that it could be moved in and out of its 5.5. enclosure of 2.5 m length, 1.4 m width and 1.5 m height. Each module has three spark gap switches, 6-capacitors of 0.7I^F, 50kV ratings, three ground resistors of 20kQ and 6-charging resistors of 2.5kQ. All these components are mounted on a 1400 mm long, 1200 mm wide and 30 mm thick Perspex sheet with sufficient track distance from the ground point as well as from stage capacitor, spark gaps and charging resistors. The charging path is through flexible cable but discharge path is 50mm 5.5. tubular pipe with rigid connections between two modules, which acts like a jumper of 300k V. Output connection of the Marx generator is taken through a 100mm corona free structure in the center of a 1 m diameter port of the tank. This tank is provided with transformer oil filling and degassing facilities for insulating the parts of Marx generator during operation. All spark gap switches are kept under high-pressure nitrogen gas. This system has been tested with two modules in series at low charging voltage of 10kV and the results are presented here

[en] A 120 kHz, 300 kV single-layer air-core toroidal transformer has been developed and commissioned at Electron Beam Centre, Kharghar, for 3 MeV, 30 kW DC beam accelerator. This paper describes the analysis of stray capacitances of this transformer with the help of MATLAB program using integration technique. The stray capacitances significantly affect the high frequency performance of the inductor behavior by bringing down the self resonant frequency and in turn the Q-factor

[en] Pulsed High Power Electron Beams with peak power of several gigawatts are useful to generate High Power Microwaves and x-rays. Beams with energy ranging from 100 keV to several MeV, current from few kilo amperes to mega amperes and pulse duration and of a few nanoseconds to a microsecond are used for these applications. In order to generate the beams with current of several kilo amperes with current density ≥ kA/cm² vacuum field emission method is used. A high voltage pulse ≥100 kV/cm is generated by using a pulse power system and applied between the anode and cathode of a field emission diode. The electric field at the micro tips on the surface of the cathode would be enhanced by several hundred times over the macroscopic field. This field causes electron emission from the micro tips and the tips are evaporated due to heating caused by the current and as a result, plasma of density 10¹⁶cm^-3 is formed in a few nano seconds on the surface of the cathode. The electrons from the cathode plasma are accelerated towards the anode by the applied electric field and form the beam. In this paper the generation of a pulsed high power electron beam with peak power of 2.5 GW is described