| Paper |
Title |
Page |
| WEPMA144 |
High Power Microwave Generation From Coaxial Virtual Cathode Oscillator
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523 |
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- A. Roy, RM. Menon, S. Mitra, K. C. Mittal, J. Mondal, D. D. Praveen Kumar, A. S. Sharma
BARC, Mumbai
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A coaxial virtual cathode oscillator (VIRCATOR) has been designed to generate Relativistic Electron Beams and High Power Microwaves. Coaxial virtual cathode oscillators are known for better efficiency compared to the axial virtual cathode oscillators. This Coaxial VIRCATOR has been designed for the KALI-5000 (1MeV, 60kA, 100 ns) pulse power system. Provision for a large anode cathode gap has been kept to avoid the prepulse effect during the electron beam generation from the KALI-5000 system. Experimental studies are carried out to generate and characterize Relativistic Electron Beams and High Power Microwaves. Relativistic Electron Beams are generated by the Coaxial Explosively emitted graphite cathodes. Electron beam voltage has been measured by a copper sulphate voltage divider and beam current by a B-dot probe. High Power Microwaves are detected by the glow of neon lamps placed closed to the output window.
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| THPMA070 |
Characterisation of Amorphous Magnetic Material with Multiple Pulse Excitation
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732 |
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- A. S. Sharma, S. Acharya, K. V. Nagesh
BARC, Mumbai
- U. Kumar, G. R. Nagabhushana
IISC, Bangalore
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An experimental investigation for the understanding of magnetic core saturation behaviour under pulse excitation is presented in this paper. The effect of repetitive shots, after resetting, on the magnetic properties of toroidal amorphous core of size 160/240/25 mm is reported. This study is made using 20kV, 20, and 200ns square pulse source, to realize the various steps which an amorphous core undergoes on saturation as well as corresponding changes in magnetic parameters viz. magnetization force, total flux swing and relative permeability. The most significant effect of pulsing is seen at higher values of operating flux, compared to lower flux regimes. Effects of number of turns and input power level to the core are also shown in this paper. It has been shown that the total energy required to saturate the core in multiple pulses is less if peak input is smaller than that in case of higher peak pulse excitation. Keyword: amorphous core, multiple pulses, effect of turns, pulse excitation
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| THPMA071 |
Study of Insulation Coordination in the Presence of Multiple Dielectric Materials
|
735 |
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- S. Mitra, D. P. Chakravarthy, K. V. Nagesh, D. D. Praveen Kumar, A. K. Ray, A. S. Sharma
BARC, Mumbai
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Use of various dielectric materials for insulation is inevitable in high voltage systems. Choosing a particular insulating material (solid, liquid, and gas) depends on various factors like the nature of the system, insulation level required, dielectric strength and thermal & mechanical stress handling capability of the material. Besides the surface break down strength of two material interfaces plays important role in the high voltage design considerations of the system. This paper critically analyses the field stress in high voltage points in presence of multiple dielectric media, in particular on the existing system of Kilo Ampere Linear Injector (KALI – 5000) system. In this paper, local field enhancement phenomenon due to presence of different solid and liquid dielectrics is evaluated. Mathematical derivations of the percentage increment of field, at the critical point, due to presence of hybrid dielectric materials, are calculated for planar, spherical and cylindrical geometry of the high voltage elements. 2-D simulations of the same to support the mathematical calculations are done using MAXWELL SV software.
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| THPMA073 |
Artificial Neural Network Calculates Backward Wave Oscillator Parameters Reliably For Pulsed Accelerators
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738 |
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- A. Gokhale
Terna Collage of Engineering, Navi Mumbai
- B. P. Dubey
Bhabha Atomic Research Center, Computer Division, Mumbai
- A. S. Sharma
BARC, Mumbai
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A method of quickly and accurately getting the dispersion curves for a slow wave structure filled with plasma is investigated. A universal dispersion equation is derived by utilizing the field theory and expressing the slow wave structure's profile in a finite Fourier series. In principle simulation program takes nearly 6 to 8 hours to generate a single result. A trained Artificial Neural Network, used in this study, calculates the BWO dispersion curve in a fraction of a second accurately and reliably.
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| THPMA064 |
Development of a 200keV Linear Induction Accelerator
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720 |
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- K. V. Nagesh, S. Acharya, R. Agarwal, D. P. Chakravarthy, S. Mitra, K. C. Mittal, D. D. Praveen Kumar, R. N. Rajan, S. R. Raul, P. C. Saroj, A. S. Sharma, D. K. Sharma
BARC, Mumbai
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Electron Linear Induction Accelerator (LIA) are for applications for applications in High Power Microwaves (HPM), high gradient accelerators, flash X-Ray radiography (FXR), flue gas clean-up, detoxification of chemicals, cross-linking of polymers, sterilization of food and medical devices, etc. The LIA-200 being developed at APPD/BARC consists of three main phases of pulse compression and voltage amplification, viz; (i)solid-state pulse modulator uses semiconductor devices, (ii)Pulse compression and voltage amplification stages, steps up to 200kV, 5 micro-seconds and compresses these pulses to 75kV, 10kA, 50ns in five stage and (iii)three induction cavities in ADDER mode for relativistic electron beam generation, with matched impedance of 5 ohms. Metglas cores have been used in the switches, cavities and pulse transformers. Deminaralized water capacitors and water transmission lines have been used for low impedance energy storage and compactness. The complete system has been assembled and ready for commissioning. LIA system will be operated from a PLC based control system which is under testing.
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