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| MOPP004 | Design and Development of Pulsed Modulators for RF Electron Linacs | 55 |
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| Pulsed Modulators required for RF sources, based on klystrons and magnetrons, for RF electron linacs have been designed and developed at Electron Beam Centre, BARC, Mumbai, India. Electron guns in these linacs have also been powered by pulsed modulators. Line-type modulators, as well as IGBT-based solid-state modulators have been developed for these applications. A 150 kV/100 A line-type modulator has been tested on klystron to generate 7 MW peak RF Power. Magnetron modulator has undergone testing up to 40 kV, 165 A on resistive load. Solid-state modulator, using fractional-turn pulse transformer has been designed, developed and tested successfully on magnetron load up to output power of 1.3 MW peak. A transformerless solid-state modulator for electron gun of 6 MeV cargo-scanning linac, uses the Marx adder configuration and has been successfully tested up to 40 kV. In addition, line-type modulators for electron guns up to 85 kV have been successfully commissioned and are in operation in the linac systems. This paper describes the salient design features of these modulators, development of pulse transformers, details of test set-up and discusses the test results of these modulators. | ||
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Poster MOPP004 [2.343 MB] | |
| MOPP005 | High Power Electron Accelerator Programme at BARC | 58 |
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| Bhabha Atomic Research Centre in India has taken up the indigenous design & development of high power electron accelerators for industrial, research and cargo-scanning applications. For this purpose, Electron Beam Centre (EBC) has been set up at Navi Mumbai, India. Pulsed RF Linacs, with on-axis coupled cavity configuration, include the 10 MeV Industrial RF linac, as well as 9 MeV linac and compact 6 MeV linac for cargo-scanning applications. Industrial DC accelerators include a 500 keV Cockroft-Walton machine and 3 MeV Dynamitron. Several radiation processing applications, such as material modification, food preservation, flue-gas treatment, etc. have been demonstrated using these accelerators. Cargo-scanning linacs have been successfully commissioned and are being characterized for the required x-ray output. A 30 MeV RF Linac, for research applications, such as shielding studies and n-ToF experiments, is being designed and developed. For ADS studies, a 100 MeV, 100 kW RF Linac system is proposed. This paper presents the details of the design of these accelerators, their development, current status and utilization for various applications. | ||
| MOPP007 | SF6 Gas Monitoring and Safety for DC Electron Beam Accelerator at EBC, Kharghar, Navi Mumbai | 61 |
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| A 3 MeV, 30kW DC Industrial electron beam accelerator has been designed, commissioned and tested at Electron beam centre, Kharghar. The accelerator has been tested upto 5 kW power level with SF6 gas at 6 kg/cm2. The accelerating column, high voltage multiplier column, electron gun and its power supply are housed in accelerator tank, which is filled with SF6 gas as gaseous insulator at 6 kg/cm2. The SF6 gas is being used due to high dielectric strength and excellent heat transfer characteristics. The SF6 gas is non toxic and non carcinogenic. The SF6 gas replaces oxygen hence the TLV (threshold limiting value) is 1000 ppm for inhaled gas for persons working on the SF6 gas handling system. The SF6 gas is being green house gas, leak tightness has to monitor in the system and leak if any should be repaired. The gas should be used, recycled and reuse and thus saving the environment. This paper describes the safety and monitoring of the SF6 gas leak, quality and precautions in 3MeV accelerator. | ||
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Poster MOPP007 [1.389 MB] | |
| TUPP006 | Design of Relativistic Magnetron for High Power Microwave Generation | 452 |
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A Linear Induction Accelerator based upon magnetic storage, utilising magnetic switches has been made and it is capable of providing a 400 kV diode voltage, 4 kA beam current for 100 ns pulse duration with 100 Hz repetition rate. It operates in a very high repetition rate due to the use of magnetic switches in it. The lesser shot to shot variation make this system ideal for a Relativistic Magnetron operation, where a huge dependence of output power on applied voltage and applied current is observed. A relativistic magnetron with axial extraction is analytically designed and simulated for this system. This relativistic magnetron is expected to give a power of 100 MW per pulse when operated in its full rating. The design features of this relativistic magnetron are presented here. This magnetron was designed for an output microwave frequency of 2.52 GHz.
*J. Benford, ''Space Applications of High-Power Microwaves'', IEEE Trans. Plasma Sci., vol. 36, no. 3, pp. 569–581, Jun. 2008 |
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| TUPP007 | Multi Gigawatt High Current Pulsed Electron Accelerator Technology Development Program at BARC | 456 |
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High current intense electron beams were investigated earlier for Flash X-rays and nuclear electromagnetic pulse generation. Starting with moderate parameters of 200 kV, 6 kA, 60 ns pulsed electron beam source from a system named Kilo Ampere Linear Injector (KALI-75) our latest development is KALI-30 GW system rated for 1 MV, 30 kA, 80 ns. First repetitive pulse LINAC without spark gap switching was developed as Linear Induction Accelerator (LIA-200) for technology demonstrations at 100 Hz. Also a repetitive Marx generator coupled reflex triode system to operate at 10 Hz. Next to this series of development LIA-400 has been developed to a capacity of 400 kV, 4 kA, 100 ns, 300 Hz. To make these pulse power systems applicable for big LINAC projects like nToF studies or ADS program, a high current electron gun has also been developed to give 100 A, 2 ns,10 Hz pulses.
References [1].Amitava Roy et al, Journal of App. Physics 103, 2008. [2].D. D. P. Kumar, et al. Rev. Sci. Inst., vol. 78, no. 11, 2007. [3].Archana Sharma, et al., IEEE-PS Vol. 39, No. 5, 2011. |
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| THPP003 | Cooling of High Pressure Insulating Gas for 3 MeV DC Accelerator: an Alternate Approach | 839 |
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| 3 MeV Accelerator Project working inside the ‘Electron Beam Centre’ (EBC) building at Kharghar, Navi Mumbai. Generally in DC and Pelletron accelerators Nitrogen/SF6 gas is taken out from accelerator tank and it is cooled by separate heat exchanger and blower unit outside the accelerator tank. In our alternate approach we have designed fan/ blower to work under high pressure inside accelerator tank. Fans are designed to work in high pressure SF6 environment at 7 bar absolute pressure with 42 kg/m3 SF6 gas density. Fan throughs air over radiator type finned tube heat exchanger, installed inside accelerator tank. Fan speeds are controlled through variable frequency drive. Two numbers of such assemblies are fabricated, installed and tested in Nitrogen and SF6 gas environment at different pressure and variable fan speed. Performances are recorded and plotted in graphical form. These cooling systems are shown excellent performance in last five years. Paper will discuss about design of cooling system, cooling calculation of fan, fabrication of fan and heat exchanger, 5 TR chiller unit, variable frequency drive, fan performance etc. | ||
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Poster THPP003 [1.644 MB] | |