RuPAC2014 - Classification: 10 RF power structures and systems

Paper

Title

Page

RF System of the Booster of NICA Facility

26

G.Y. Kurkin, A.M. Batrakov, G.A. Fatkin, Ya.G. Kruchkov, S.A. Krutikhin, S.V. Motygin, A.M. Pilan
BINP SB RAS, Novosibirsk, Russia
G.A. Fatkin
NSU, Novosibirsk, Russia

The project NICA is being constructed in JINR, Dubna to provide collisions of heavy ion beams in the energy range from 1 to 4.5 GeV/u at the luminosity level of 1*10²⁷ cm^-2*s⁻¹. One of the elements in the collider injection chain is BUSTER – a cycling accelerator of ions 197Au³²⁺. The injection energy of particles is 6.2 MeV/u, extraction energy is 600 MeV/u. Two RF stations are to provide 10 kV of acceleration voltage. Frequency range of operation of the stations in the injector chain is from 634 kHz to 2400 kHz. The provisions are made for autonomous mode of operation of the stations in the frequency range of 0.5 – 5.5 MHz at the same accelerating voltage. Amorphous metal rings of Russian production are used in the RF cavities. RF stations are created in the Budker Institute of Nuclear Physics, SB RAS, Novosibirsk. The stations are tested in the operative mode and will be delivered to the customer in October, 2014. Main design features and parameters of RF cavity, power generator and control system of the stations are described in the paper.

Slides TUCB02 [1.265 MB]

WEPSB01

Modernization the Modulator of the RF-Generator Ion Linear Accelerator LU-20

155

V. Kobets, A. Govorov, V. Monchinsky
JINR, Dubna, Moscow Region, Russia
A.V. Butenko, D.E. Donets, A.O. Sidorin
JINR/VBLHEP, Moscow, Russia

The report discusses the replacement of the lamp key the modulator semiconductor. A schematic of the modulator and a semiconductor switch scheme protection against voltage surges in the generator lamp. Replacing the lamp key it possible to increase the output power generator.

WEPSB02

Modernization the Modulators Klystrons Accelerating Stand of the Electron Linear Accelerator LINAC-800

157

V. Kobets
JINR, Dubna, Moscow Region, Russia

The report discusses the modernization of the modulators klystrons of the first and second accelerating stations of the acceleration stand on the basis of an electron linear accelerator LINAC-800. Results of the analysis of the modulators to determine the conditions of modernization and upgrading. The presented results of work new modulators.

WEPSB03

System Power Microwave Impulse Compression Based on Double Forming Line

159

G.O. Buyanov, P.G. Alexey, O.A. Andrey, A.P. Klachkov
MEPhI, Moscow, Russia

Keywords: double forming line (DFL), compressor microwave pulses, microwave plasma discharger, resonator – storage, input power device (an input power), energy output device. The first part is devoted to the calculation and design compressor using a single-mode waveguides. We investigated the processes of accumulation and energy extraction from the resonator – storage of compressor, the dependence of the efficiency of energy extraction from the compressor on the plasma parameters of the discharge gap: n, q, m, v, r, h - the concentration, charge, mass, the frequency of collisions of free electrons, the radius and height of the cylinder through which flows the discharge. Refinement construction site energy output and its optimization, matching waveguide resonator - drive to the waveguide load in deriving energy from the compressor microwave was produced. The concept of a multi-compressor DFL was proposed and optimization under axial field was make to increase the dielectric strength and reduce the inductance of the discharge gap. In the second part of the paper questions, the design of the compressor DFL on oversized waveguides with working mode H01n was discusses. New constructions of power input devices was propose that allow not only to providing the necessary coupling coefficient with the feed path, but also greatly reduced the excitation of unacceptable modes in the resonator – storage.

WEPSB04

Field Optimization Technique of the Multigap H-mode Resonators

162

S.E. Toporkov, A.B. Buleiko, M.V. Lalayan
MEPhI, Moscow, Russia

Optimization of the H-mode resonators requires uniform accelerating field distribution on its axes. To realize this task pylons with the holes on its end walls are used in many cases. During applying this technique in case of cavities with low number of periods it was mentioned that the best value of the field flatness was obtained in case of zero gap between end walls of the resonator and the pylon. It means that each pylon has got the electrical contact with one of the end walls of the resonator. For such cavity geometry magnetic field distribution differs from the classical H – resonator: it transforms in one common magnetic flux like in split-coaxial cavities. The analysis of such structures was performed for two types of H-mode resonators: Cross bar H-mode (CH) resonators with working frequency 324MHz and Interdigital H-mode (IH) resonators with working frequency 162MHz. All types of resonators work on the pi-mode and have 9 accelerating gaps. The main stages of E-field flatness optimization inside CH⁻ and IH⁻ cavities are presented at this paper.

WEPSB05

Optimization of Electric Field Distribution Inside Multi-gap CH-Resonator

164

S.E. Toporkov
MEPhI, Moscow, Russia

This paper presents the results of the electrodynamic modelling of the Crossbar H-mode (CH) resonator. The main goal was to get the uniform accelerating field distribution and to optimize effective shunt impedance. The initial model of the 324 MHz cavity consists of 7 equidistant RF gaps with the period length 46.26 mm. To optimize its electrodynamic characteristics the design contains pylons. Solution of the tuning task consists of several steps. Firstly it was chosen the optimal relation between the holding rod length and the pylon's height. Then the most significant improvement on the E-field distribution was introduced by optimizing the gap between end walls of the resonator and the pylon. The final adjustment of the field distribution and the tuning to the working frequency was performed by means of the holes in the pylon. Correct geometry increases effective shunt impedance from 55 MOhm/m to 80 MOhm/m and improves the field flatness to the 97%. The results of optimization the cavities for different particle velocities with 7,9 and 11 accelerating gaps and different aperture diameter are presented.

WEPSB06

The Optimization of the Buncher at 145.2 MHz to Reduce Multipactor Effect

166

M. Gusarova, T. Kulevoy, I.I. Petrushina, A.S. Plastun, S.M. Polozov
MEPhI, Moscow, Russia
T. Kulevoy, A.S. Plastun
ITEP, Moscow, Russia

The results of the optimization of the cavity of the single gap buncher at 145.2 MHz to reduce multipacting effect are presented. Resonant voltages, impact energies and corresponding particle trajectories are obtained. The variants of design to reduce multipacting effect are considered.

WEPSB07

MultP-M Code Geometry Import Module Performance Optimization

169

M. Gusarova, S. Khudyakov, M.V. Lalayan
MEPhI, Moscow, Russia

The new possibilities of three-dimensional modeling program multipactor MultP-M are presented. On an example, consider an increase in the speed and accuracy of the calculation using a new algorithm for calculating the use of loading geometry format STL.

WEPSB08

Multi-beam Generator Cavity for the Proton Linear Accelerator Feeding System on 991 MHz Frequency Geometry Optimization

171

E.A. Savin, S.V. Matsievskiy, N.P. Sobenin
MEPhI, Moscow, Russia
A.A. Zavadtsev
Nano, Moscow, Russia

For the proton linear accelerator feeding system 800 kW input power value is required. The system consists from pillbox cavity with six beam tubes connected to the rectangular waveguide as a power output system is designed. In case of using high voltage gun with modulated six-bunch injection, this system allows to transform the energy of electron bunches which flies throw beam tubes to accelerating section feeding power. Different types of the structure geometry were calculated. The whole structure consists both from generator cavity and accelerating structure has been designed.

WEPSB11

Test Results of 433 MHz Deuteron Linac (RFQ)

177

Y.A. Svistunov, S.V. Grigorenko, A.N. Kuzhlev, A.K. Liverovskij, I.I. Mezhov, A.A. Ryaskov, A.P. Strokach, V.F. Tsvetkov, O.L. Veresov, Yu. Zuev
NIIEFA, St. Petersburg, Russia

The results of bench tests of the high frequency deuteron accelerator (RFQ) with output energy of 1 MeV and operating frequency of 433 MHz are presented. There are briefly discussed RFQ construction and assembling, rf system, issues of tuning and measuring of electrodynamical characteristics of RFQ. Output data obtained under accelerated beam operation with foil monitor and Beryllium target are given.

WEPSB12

Cascade Interference Switches for Active Microwave Compressors

180

S.A. Gorev, S.N. Artemenko, V.A. Avgustinovich, V.S. Igumnov, V.L. Kaminski, S.A. Novikov, Yu.G. Yushkov
TPU, Tomsk, Russia

Funding: "Science" state order of the Russian Ministry of Education and Science.
Results of study energy extraction devices for S-band microwave pulse compressors are presented. The devices are manufactured as interference switches produced from the circular single mode waveguide and that are differs only by the cascade of identical H-plane T-junctions connected in series at a side arm of H-tee. The versions cascade switches which are matched and unmatched from the side of auxiliary arm of T-junction are investigated. It is shown the variant of cascade switches with the matched T-junctions allows decrease the switching power level few times comparatively the switching power of usual one. Possibility of increasing operation power and stability of output pulses of microwave pulse compressors with such energy extraction devices are confirmed in experiments. There are presented the results of investigation the cascade including two and three switches connected in series by straight arms. It is shown the switching power level for such type cascade switches can be many less than for usual switch with one T-junction. Results of experimental study cascade switches of such type confirming with the results of the theoretical analyses are presented and peculiarities of cascade switches are mentioned. The assumption about good perspectives for the cascade switches manufactured from oversized rectangular waveguide is formulated. The obtained results concerning of the cascade switch operation have been demonstrated the possibility of increasing switch operation power.

WEPSB13

Oversized Interference Switches of Active Microwave Pulse Compressors

183

V.S. Igumnov, S.N. Artemenko, V.A. Avgustinovich, S.A. Gorev, V.L. Kaminski, S.A. Novikov, Yu.G. Yushkov
TPU, Tomsk, Russia

Funding: "Science" state order of the Russian Ministry of Education and Science.
Results of simulation and experimental study of two types of the oversized interference switches are presented. The switch of the first type was developed on basis of the simulation of the oversized rectangular waveguide H-tee with the H01 operation mode. Conditions of effective operation of the first type switch as an energy extraction element of active microwave pulse compressors are determined. The output pulse power of 2.8 MW and pulse width of 3.5 ns with the corresponding amplification factor of 17.5 dB for were obtained in the X-band microwave pulse compressor prototype containing the storage cavity made of WR-284 waveguide and the switch made of the waveguide with the cross section area of 58×25 mm2. The results of experimental study of the oversized X-band interference switch of the second type with the synchronous energy extraction through a compact packet of common single mode switches incorporating the five identical waveguide tees are presented as well. Possibility of full synchronization of the switch packet is proved and the conditions of such synchronization are determined. Permissible quantity of the switches in a packet unit is estimated. The output pulse power of 0.8 MW, pulse width of 3.2 ns at the power gain of 12 dB and the pulse power of 2.2 MW, pulse width of 3.5 ns at the power gain of 16.5 dB were obtained when the energy extraction from the five different single mode resonant cavities and an oversized cavity respectively was synchronous.

THX02

Experience in Research, Development, Construction and Commissioning of Normally Conducting Accelerating Structures

278

V.V. Paramonov, L.V. Kravchuk
RAS/INR, Moscow, Russia

The experience and results of research, development, construction and start of normally conducting accelerating structures for high intensity hadron linear accelerators at medium and high energii is summarized Created methods and obtained results provided construction and start of operation of accelerating system in INR H⁻ linac with designed energy 600 MeV. The research results allow generalize the properties of high energy structures and develop methods and criteria for improvements, with were realized in the development and commissioning of accelerating structures in another foreign laboratories. Basing on research results, the high energy accelerating structure, which surpasses analogues in the total list of parameters, is proposed and approved.

Slides THX02 [1.259 MB]

Paper	Title	Page
TUCB02	RF System of the Booster of NICA Facility	26
	G.Y. Kurkin, A.M. Batrakov, G.A. Fatkin, Ya.G. Kruchkov, S.A. Krutikhin, S.V. Motygin, A.M. Pilan BINP SB RAS, Novosibirsk, Russia G.A. Fatkin NSU, Novosibirsk, Russia
	The project NICA is being constructed in JINR, Dubna to provide collisions of heavy ion beams in the energy range from 1 to 4.5 GeV/u at the luminosity level of 110²⁷ cm^-2s⁻¹. One of the elements in the collider injection chain is BUSTER – a cycling accelerator of ions 197Au³²⁺. The injection energy of particles is 6.2 MeV/u, extraction energy is 600 MeV/u. Two RF stations are to provide 10 kV of acceleration voltage. Frequency range of operation of the stations in the injector chain is from 634 kHz to 2400 kHz. The provisions are made for autonomous mode of operation of the stations in the frequency range of 0.5 – 5.5 MHz at the same accelerating voltage. Amorphous metal rings of Russian production are used in the RF cavities. RF stations are created in the Budker Institute of Nuclear Physics, SB RAS, Novosibirsk. The stations are tested in the operative mode and will be delivered to the customer in October, 2014. Main design features and parameters of RF cavity, power generator and control system of the stations are described in the paper.
	Slides TUCB02 [1.265 MB]

WEPSB01	Modernization the Modulator of the RF-Generator Ion Linear Accelerator LU-20	155
	V. Kobets, A. Govorov, V. Monchinsky JINR, Dubna, Moscow Region, Russia A.V. Butenko, D.E. Donets, A.O. Sidorin JINR/VBLHEP, Moscow, Russia
	The report discusses the replacement of the lamp key the modulator semiconductor. A schematic of the modulator and a semiconductor switch scheme protection against voltage surges in the generator lamp. Replacing the lamp key it possible to increase the output power generator.

WEPSB02	Modernization the Modulators Klystrons Accelerating Stand of the Electron Linear Accelerator LINAC-800	157
	V. Kobets JINR, Dubna, Moscow Region, Russia
	The report discusses the modernization of the modulators klystrons of the first and second accelerating stations of the acceleration stand on the basis of an electron linear accelerator LINAC-800. Results of the analysis of the modulators to determine the conditions of modernization and upgrading. The presented results of work new modulators.

WEPSB03	System Power Microwave Impulse Compression Based on Double Forming Line	159
	G.O. Buyanov, P.G. Alexey, O.A. Andrey, A.P. Klachkov MEPhI, Moscow, Russia
	Keywords: double forming line (DFL), compressor microwave pulses, microwave plasma discharger, resonator – storage, input power device (an input power), energy output device. The first part is devoted to the calculation and design compressor using a single-mode waveguides. We investigated the processes of accumulation and energy extraction from the resonator – storage of compressor, the dependence of the efficiency of energy extraction from the compressor on the plasma parameters of the discharge gap: n, q, m, v, r, h - the concentration, charge, mass, the frequency of collisions of free electrons, the radius and height of the cylinder through which flows the discharge. Refinement construction site energy output and its optimization, matching waveguide resonator - drive to the waveguide load in deriving energy from the compressor microwave was produced. The concept of a multi-compressor DFL was proposed and optimization under axial field was make to increase the dielectric strength and reduce the inductance of the discharge gap. In the second part of the paper questions, the design of the compressor DFL on oversized waveguides with working mode H01n was discusses. New constructions of power input devices was propose that allow not only to providing the necessary coupling coefficient with the feed path, but also greatly reduced the excitation of unacceptable modes in the resonator – storage.

WEPSB04	Field Optimization Technique of the Multigap H-mode Resonators	162
	S.E. Toporkov, A.B. Buleiko, M.V. Lalayan MEPhI, Moscow, Russia
	Optimization of the H-mode resonators requires uniform accelerating field distribution on its axes. To realize this task pylons with the holes on its end walls are used in many cases. During applying this technique in case of cavities with low number of periods it was mentioned that the best value of the field flatness was obtained in case of zero gap between end walls of the resonator and the pylon. It means that each pylon has got the electrical contact with one of the end walls of the resonator. For such cavity geometry magnetic field distribution differs from the classical H – resonator: it transforms in one common magnetic flux like in split-coaxial cavities. The analysis of such structures was performed for two types of H-mode resonators: Cross bar H-mode (CH) resonators with working frequency 324MHz and Interdigital H-mode (IH) resonators with working frequency 162MHz. All types of resonators work on the pi-mode and have 9 accelerating gaps. The main stages of E-field flatness optimization inside CH⁻ and IH⁻ cavities are presented at this paper.

WEPSB05	Optimization of Electric Field Distribution Inside Multi-gap CH-Resonator	164
	S.E. Toporkov MEPhI, Moscow, Russia
	This paper presents the results of the electrodynamic modelling of the Crossbar H-mode (CH) resonator. The main goal was to get the uniform accelerating field distribution and to optimize effective shunt impedance. The initial model of the 324 MHz cavity consists of 7 equidistant RF gaps with the period length 46.26 mm. To optimize its electrodynamic characteristics the design contains pylons. Solution of the tuning task consists of several steps. Firstly it was chosen the optimal relation between the holding rod length and the pylon's height. Then the most significant improvement on the E-field distribution was introduced by optimizing the gap between end walls of the resonator and the pylon. The final adjustment of the field distribution and the tuning to the working frequency was performed by means of the holes in the pylon. Correct geometry increases effective shunt impedance from 55 MOhm/m to 80 MOhm/m and improves the field flatness to the 97%. The results of optimization the cavities for different particle velocities with 7,9 and 11 accelerating gaps and different aperture diameter are presented.

WEPSB06	The Optimization of the Buncher at 145.2 MHz to Reduce Multipactor Effect	166
	M. Gusarova, T. Kulevoy, I.I. Petrushina, A.S. Plastun, S.M. Polozov MEPhI, Moscow, Russia T. Kulevoy, A.S. Plastun ITEP, Moscow, Russia
	The results of the optimization of the cavity of the single gap buncher at 145.2 MHz to reduce multipacting effect are presented. Resonant voltages, impact energies and corresponding particle trajectories are obtained. The variants of design to reduce multipacting effect are considered.

WEPSB07	MultP-M Code Geometry Import Module Performance Optimization	169
	M. Gusarova, S. Khudyakov, M.V. Lalayan MEPhI, Moscow, Russia
	The new possibilities of three-dimensional modeling program multipactor MultP-M are presented. On an example, consider an increase in the speed and accuracy of the calculation using a new algorithm for calculating the use of loading geometry format STL.

WEPSB08	Multi-beam Generator Cavity for the Proton Linear Accelerator Feeding System on 991 MHz Frequency Geometry Optimization	171
	E.A. Savin, S.V. Matsievskiy, N.P. Sobenin MEPhI, Moscow, Russia A.A. Zavadtsev Nano, Moscow, Russia
	For the proton linear accelerator feeding system 800 kW input power value is required. The system consists from pillbox cavity with six beam tubes connected to the rectangular waveguide as a power output system is designed. In case of using high voltage gun with modulated six-bunch injection, this system allows to transform the energy of electron bunches which flies throw beam tubes to accelerating section feeding power. Different types of the structure geometry were calculated. The whole structure consists both from generator cavity and accelerating structure has been designed.

WEPSB11	Test Results of 433 MHz Deuteron Linac (RFQ)	177
	Y.A. Svistunov, S.V. Grigorenko, A.N. Kuzhlev, A.K. Liverovskij, I.I. Mezhov, A.A. Ryaskov, A.P. Strokach, V.F. Tsvetkov, O.L. Veresov, Yu. Zuev NIIEFA, St. Petersburg, Russia
	The results of bench tests of the high frequency deuteron accelerator (RFQ) with output energy of 1 MeV and operating frequency of 433 MHz are presented. There are briefly discussed RFQ construction and assembling, rf system, issues of tuning and measuring of electrodynamical characteristics of RFQ. Output data obtained under accelerated beam operation with foil monitor and Beryllium target are given.

WEPSB12	Cascade Interference Switches for Active Microwave Compressors	180
	S.A. Gorev, S.N. Artemenko, V.A. Avgustinovich, V.S. Igumnov, V.L. Kaminski, S.A. Novikov, Yu.G. Yushkov TPU, Tomsk, Russia
	Funding: "Science" state order of the Russian Ministry of Education and Science. Results of study energy extraction devices for S-band microwave pulse compressors are presented. The devices are manufactured as interference switches produced from the circular single mode waveguide and that are differs only by the cascade of identical H-plane T-junctions connected in series at a side arm of H-tee. The versions cascade switches which are matched and unmatched from the side of auxiliary arm of T-junction are investigated. It is shown the variant of cascade switches with the matched T-junctions allows decrease the switching power level few times comparatively the switching power of usual one. Possibility of increasing operation power and stability of output pulses of microwave pulse compressors with such energy extraction devices are confirmed in experiments. There are presented the results of investigation the cascade including two and three switches connected in series by straight arms. It is shown the switching power level for such type cascade switches can be many less than for usual switch with one T-junction. Results of experimental study cascade switches of such type confirming with the results of the theoretical analyses are presented and peculiarities of cascade switches are mentioned. The assumption about good perspectives for the cascade switches manufactured from oversized rectangular waveguide is formulated. The obtained results concerning of the cascade switch operation have been demonstrated the possibility of increasing switch operation power.

WEPSB13	Oversized Interference Switches of Active Microwave Pulse Compressors	183
	V.S. Igumnov, S.N. Artemenko, V.A. Avgustinovich, S.A. Gorev, V.L. Kaminski, S.A. Novikov, Yu.G. Yushkov TPU, Tomsk, Russia
	Funding: "Science" state order of the Russian Ministry of Education and Science. Results of simulation and experimental study of two types of the oversized interference switches are presented. The switch of the first type was developed on basis of the simulation of the oversized rectangular waveguide H-tee with the H01 operation mode. Conditions of effective operation of the first type switch as an energy extraction element of active microwave pulse compressors are determined. The output pulse power of 2.8 MW and pulse width of 3.5 ns with the corresponding amplification factor of 17.5 dB for were obtained in the X-band microwave pulse compressor prototype containing the storage cavity made of WR-284 waveguide and the switch made of the waveguide with the cross section area of 58×25 mm2. The results of experimental study of the oversized X-band interference switch of the second type with the synchronous energy extraction through a compact packet of common single mode switches incorporating the five identical waveguide tees are presented as well. Possibility of full synchronization of the switch packet is proved and the conditions of such synchronization are determined. Permissible quantity of the switches in a packet unit is estimated. The output pulse power of 0.8 MW, pulse width of 3.2 ns at the power gain of 12 dB and the pulse power of 2.2 MW, pulse width of 3.5 ns at the power gain of 16.5 dB were obtained when the energy extraction from the five different single mode resonant cavities and an oversized cavity respectively was synchronous.

THX02	Experience in Research, Development, Construction and Commissioning of Normally Conducting Accelerating Structures	278
	V.V. Paramonov, L.V. Kravchuk RAS/INR, Moscow, Russia
	The experience and results of research, development, construction and start of normally conducting accelerating structures for high intensity hadron linear accelerators at medium and high energii is summarized Created methods and obtained results provided construction and start of operation of accelerating system in INR H⁻ linac with designed energy 600 MeV. The research results allow generalize the properties of high energy structures and develop methods and criteria for improvements, with were realized in the development and commissioning of accelerating structures in another foreign laboratories. Basing on research results, the high energy accelerating structure, which surpasses analogues in the total list of parameters, is proposed and approved.
	Slides THX02 [1.259 MB]