LINAC2014 - List of Authors (Dixit, K.P.)

Paper

Title

Page

Design and Development of Pulsed Modulators for RF Electron Linacs

55

K.P. Dixit, S. Chandan, N. Chaudhary, R.B. Chavan, L.M. Gantayet, S.R. Ghodke, M. Kumar, K.C. Mittal, H.E. Sarukte, A.R. Tillu, H. Tyagi, V. Yadav
BARC, Mumbai, India

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.

Poster MOPP004 [2.343 MB]

MOPP005

High Power Electron Accelerator Programme at BARC

58

K.C. Mittal, S. Acharya, R.I. Bakhtsingh, R. Barnwal, D. Bhattacharjee, S. Chandan, N. Chaudhary, R.B. Chavan, S.P. Dewangan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, D. Jayaprakash, M. Kumar, M.K. Kumar, H.K. Manjunatha, R.L. Mishra, J. Mondal, B. Nayak, S. Nayak, V.T. Nimje, S. Parashar, R. Patel, R.N. Rajan, P.C. Saroj, H.E. Sarukte, D.K. Sharma, V. Sharma, S.K. Srivasatava, N.T. Thakur, A.R. Tillu, R. Tiwari, H. Tyagi, A. Waghmare, V. Yadav
BARC, Mumbai, India

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

S.K. Suneet, S. Acharya, S. Banerjee, R. Barnwal, D. Bhattacharjee, N. Chaudhary, R.B. Chavan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, B.S. Israel, D. Jayaprakash, N. Lawangare, K. Mahender, R.L. Mishra, K.C. Mittal, B. Nayak, S. Nayak, R. Patel, R.N. Rajan, P.C. Saroj, D.K. Sharma, V. Sharma, M.K. Srvastava, D.P. Suryaprakash, N.T. Thakur, R. Tiwari, A. Waghmare
BARC, Mumbai, India

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.

Poster MOPP007 [1.389 MB]

THPP003

Cooling of High Pressure Insulating Gas for 3 MeV DC Accelerator: an Alternate Approach

839

S.R. Ghodke, S. Acharya, R. Barnwal, K.P. Dixit, L.M. Gantayet, B.S. Israel, D. Jayaprakash, K. Mahender, K.C. Mittal, S. Nayak, R.N. Rajan, D.K. Sharma, V. Sharma, S.K. Suneet, D.P. Suryaprakash
BARC, Mumbai, India

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.

Poster THPP003 [1.644 MB]

THPP004

Design, Development and Initial Results of Solid State Magnetron Modulator

843

A.R. Tillu, S. Chandan, K.P. Dixit, K.C. Mittal, H.E. Sarukte
BARC, Mumbai, India

A prototype solid state pulse modulator based on Induction Adder Topology has been designed ans is currently being tested on a S Band Pulsed magnetron rated for 3.2M W Peak RF Power. After successful lab tests the modulator is intended for use in cargo scanning and radiography applications. Currently the topology consists of 4 no.s of single turn primaries driven independently at voltages not more than 1000V. The secondary encircles all the four primaries to generate the desired pulsed voltage across the magnetron. The designed output pulse parameters are 50k V, 120A, 4micro s, at a pulse repetition rate of 250 pps. The paper describes the design and development of the Epoxy Cast Pulse transformer and the Low Inductance Primary Circuit. The rise time measured was < 400ns, and the reverse voltage at the end of the pulse was less than 12kV (at 43k V pulse). The testing was done at low PRF, on two different magnetrons having different operating points to demonstrate fairly good impedance independent operating characteristic of the magnetron modulator. Initial test results on the Resistive load and Magnetron load will also be discussed

Poster THPP004 [1.575 MB]

Paper	Title	Page
MOPP004	Design and Development of Pulsed Modulators for RF Electron Linacs	55
	K.P. Dixit, S. Chandan, N. Chaudhary, R.B. Chavan, L.M. Gantayet, S.R. Ghodke, M. Kumar, K.C. Mittal, H.E. Sarukte, A.R. Tillu, H. Tyagi, V. Yadav BARC, Mumbai, India
	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.
	Poster MOPP004 [2.343 MB]

MOPP005	High Power Electron Accelerator Programme at BARC	58
	K.C. Mittal, S. Acharya, R.I. Bakhtsingh, R. Barnwal, D. Bhattacharjee, S. Chandan, N. Chaudhary, R.B. Chavan, S.P. Dewangan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, D. Jayaprakash, M. Kumar, M.K. Kumar, H.K. Manjunatha, R.L. Mishra, J. Mondal, B. Nayak, S. Nayak, V.T. Nimje, S. Parashar, R. Patel, R.N. Rajan, P.C. Saroj, H.E. Sarukte, D.K. Sharma, V. Sharma, S.K. Srivasatava, N.T. Thakur, A.R. Tillu, R. Tiwari, H. Tyagi, A. Waghmare, V. Yadav BARC, Mumbai, India
	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
	S.K. Suneet, S. Acharya, S. Banerjee, R. Barnwal, D. Bhattacharjee, N. Chaudhary, R.B. Chavan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, B.S. Israel, D. Jayaprakash, N. Lawangare, K. Mahender, R.L. Mishra, K.C. Mittal, B. Nayak, S. Nayak, R. Patel, R.N. Rajan, P.C. Saroj, D.K. Sharma, V. Sharma, M.K. Srvastava, D.P. Suryaprakash, N.T. Thakur, R. Tiwari, A. Waghmare BARC, Mumbai, India
	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.
	Poster MOPP007 [1.389 MB]

THPP003	Cooling of High Pressure Insulating Gas for 3 MeV DC Accelerator: an Alternate Approach	839
	S.R. Ghodke, S. Acharya, R. Barnwal, K.P. Dixit, L.M. Gantayet, B.S. Israel, D. Jayaprakash, K. Mahender, K.C. Mittal, S. Nayak, R.N. Rajan, D.K. Sharma, V. Sharma, S.K. Suneet, D.P. Suryaprakash BARC, Mumbai, India
	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.
	Poster THPP003 [1.644 MB]

THPP004	Design, Development and Initial Results of Solid State Magnetron Modulator	843
	A.R. Tillu, S. Chandan, K.P. Dixit, K.C. Mittal, H.E. Sarukte BARC, Mumbai, India
	A prototype solid state pulse modulator based on Induction Adder Topology has been designed ans is currently being tested on a S Band Pulsed magnetron rated for 3.2M W Peak RF Power. After successful lab tests the modulator is intended for use in cargo scanning and radiography applications. Currently the topology consists of 4 no.s of single turn primaries driven independently at voltages not more than 1000V. The secondary encircles all the four primaries to generate the desired pulsed voltage across the magnetron. The designed output pulse parameters are 50k V, 120A, 4micro s, at a pulse repetition rate of 250 pps. The paper describes the design and development of the Epoxy Cast Pulse transformer and the Low Inductance Primary Circuit. The rise time measured was < 400ns, and the reverse voltage at the end of the pulse was less than 12kV (at 43k V pulse). The testing was done at low PRF, on two different magnetrons having different operating points to demonstrate fairly good impedance independent operating characteristic of the magnetron modulator. Initial test results on the Resistive load and Magnetron load will also be discussed
	Poster THPP004 [1.575 MB]