IPAC2021 - Classification: MC7: Accelerator Technology / T08 RF Power Sources

Paper	Title	Page
TUPAB345	Availability Modeling of the Solid-State Power Amplifiers for the CERN SPS RF Upgrade	2308
	L. Felsberger, A. Apollonio, T. Cartier-Michaud, E. Montesinos, J.C. Oliveira, J.A. Uythoven CERN, Geneva, Switzerland
	Funding: This project has received funding from the Euratom research and training programme 2019-2020 under grant agreement No 945077. As part of the LHC Injector Upgrade program a complete overhaul of the Super Proton Synchrotron Radio-Frequency (RF) system took place. New cavities have been installed for which the solid-state technology was chosen to deliver a combined RF power of 2 MW from 2560 RF amplifiers. This strategy promises high availability as the system continues operation when some of the amplifiers fail. This study quantifies the operational availability that can be achieved with this new installation. The evaluation is based on a Monte Carlo simulation of the system using the novel AvailSim4 simulation software. A model based on lifetime estimations of the RF modules is compared against data from early operational experience. Sensitivity analyses have been made, that give insight to the chosen operational scenario. With the increasing use of solid-state RF power amplifiers, the findings of this study provide a useful reference for future application of this technology in particle accelerators.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB345
About •	paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 19 August 2021
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TUPAB346	Development of a 500-MHz 150-kW Solid-State Power Amplifier for High Energy Photon Source	2312
	Y.L. Luo, T.M. Huang, J. Li, H.Y. Lin, Q. Ma, Q.Y. Wang, P. Zhang, F.C. Zhao IHEP, Beijing, People’s Republic of China
	A 500-MHz 150-kW solid-state power amplifier (SSA) has been developed to test the 500-MHz normal conducting cavities for High Energy Photon Source (HEPS) booster ring. It will also be used to power normal conducting cavities in the initial beam commissioning stage of the HEPS storage ring. A total number of 96 amplifier modules are combined initially by coaxial and later by waveguide combiners to deliver the 150-kW RF power. The final output is of EIA standard WR1800 rectangular waveguide. Each amplifier module consists four transistors equipped with individual circulator and load and outputs 2-kW RF power. Modularity, redundancy and satisfactory RF performance are demonstrated. In the final stage of HEPS project, this 150-kW amplifier will be modified to a 100-kW amplifier to join the other five 100-kW SSAs for normal operation of the booster cavities. The development and test results are presented in this paper.
	Poster TUPAB346 [1.870 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB346
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 15 August 2021
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TUPAB347	Development of a 166-MHz 260-kW Solid-State Power Amplifier for High Energy Photon Source	2315
	Y.L. Luo, T.M. Huang, J. Li, H.Y. Lin, Q. Ma, Q.Y. Wang, P. Zhang, F.C. Zhao IHEP, Beijing, People’s Republic of China
	166-MHz 260-kW solid-state power amplifiers have been chosen to drive the 166.6-MHz superconducting cavities for the storage ring of High Energy Photon Source. Highly modular yet compact are desired. A total number of 112 amplifier modules of 3 kW each are combined in a multi-stage power combining topology. The final output is of 9-3/16" 50 Ω coaxial rigid line. Each amplifier module consists of 3 LDMOS transistors with individual circulator and load. Thermal simulations of the amplifier module have been conducted to optimize cooling capabilities for both travelling-wave and full-reflection operation scenarios. High efficiency, sufficient redundancy and excellent RF performances of the 260-kW system are demonstrated. A control system is also integrated and EPICS is used to manage the monitored data. The design and test results of the amplifier system are presented in this paper.
	Poster TUPAB347 [1.972 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB347
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 29 August 2021
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TUPAB348	Magnetron R&D for High Efficiency CW RF Sources for Industrial Accelerators	2318
	H. Wang, K. Jordan, R.M. Nelson, R.A. Rimmer, S.O. Solomon JLab, Newport News, Virginia, USA B.R.L. Coriton, C.P. Moeller, K.A. Thackston GA, San Diego, California, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177, and DOE OS/HEP Accelerator Stewardship award 2019-2021. The scheme of using high-efficiency magnetrons to drive radiofrequency accelerators has been demonstrated at 2450 MHz in CW mode . Magnetron test stands at JLab and GA have been set up to further test the noise figure and the locking speed of the injection phase-lock method. For higher power applications, power combining experiments using a TM010 cavity-type combiner and a magic tee for the binary combiner while using a single clean injection signal has been carried out at 2450 MHz. The frequency pulling effect between the magnetron and a low-Q cavity has been shown to enhance the frequency locking bandwidth compared to the injection phase-lock alone. The principle has been studied by the equivalent circuit simulation, analytical model, and finally confirmed experimentally on the magnetrons. Due to the pandemic delay in 2020, the equivalent high power tests using a 75kW, 915MHz industrial magnetron will be done in 2021 and will be reported in a future paper. H. Wang, et al, Magnetron R&Ds for High-Efficiency CW RF Sources of Particle Accelerators, WEXXPLS1, proceedings of IPAC 2019, Melbourne, Australia, May 19 -24, 2019.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB348
About •	paper received ※ 22 May 2021 paper accepted ※ 21 June 2021 issue date ※ 30 August 2021
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TUPAB349	High Efficiency, Low Cost RF Sources for Accelerators and Colliders	2322
	R.L. Ives, T. Bui, G. Collins, H. Freund, T.W. Habermann, D. Marsden, M.E. Read CCR, San Mateo, California, USA B.E. Chase, J. Reid Fermilab, Batavia, Illinois, USA N. Chaudhary, J.R. Conant, T. Cox, R. Ho, C. McVey, C.M. Walker CPI, Palo Alto, California, USA J.C. Frisch, L. Ma SLAC, Menlo Park, California, USA A. Jensen Leidos Corp, Billerica, MA, USA J.M. Potter JP Accelerator Works, Los Alamos, New Mexico, USA W. Sessions Georgia Tech Research Institute, Smyrna, Georgia, USA
	Funding: U.S. Department of Energy Calabazas Creek Research, Inc. (CCR) and its collaborators are developing high efficiency, low cost RF sources. Phase and Amplitude Controlled Magnetrons: CCR, Fermilab, and Communications & Power Industries, LLC (CPI) recently developed a 100 kW, 1.3 GHz magnetron system with amplitude and phase control. The system operated at more than 80% efficiency and demonstrated rapid control of amplitude and phase. Multiple Beam Triodes: CCR, in collaboration with CPI and JP Accelerator Works, Inc., is developing 200 kW, pulsed and CW RF sources from 350 to 700 MHz with projected efficiencies exceeding 80% and cost of $0.50/Watt. Prototype tubes are scheduled for tests in spring 2021. High Efficiency Klystrons:CCR, CPI, and Leidos, Inc. are building a 1.3 GHz, 100 kW klystron operating at 80% efficiency. High power testing is scheduled for summer 2021. Multiple Beam IOTs: CCR and Georgia Tech Research Institute are developing MBIOTs with simplified input coupling and high efficiency. Simulations indicate that 3rd harmonic drive power can increase the efficiency 8-10 %. The program is developing a prototype tube to produce 200 kW peak, 100 kW average power at 704 MHz.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB349
About •	paper received ※ 18 May 2021 paper accepted ※ 01 June 2021 issue date ※ 27 August 2021
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TUPAB350	Design of 71 MHz Power Amplifier in a Single-ended Architecture for IRANCYC-10 Cyclotron	2325
	F. Babagoli Moziraji, H. Afarideh AUT, Tehran, Iran M. Dehghan Shahid Beheshti University, Tehran, Iran F. Ghasemi NSTRI, Tehran, Iran
	In this paper, the design and simulation of a high power amplifier to provide the required power of a cyclotron accelerator (IRANCYC-10) is presented step-by-step. By combining four modules of this amplifier, a power of 2.5 kW can be achieved to start the main power amplifier. The single ended designs amplifier can generate 1 kW the operating frequency of 71MHz continuous wave (CW). The purpose of choosing this type of design is simplicity to build without the need for a balun, low weight to build high power, as well as cost-effectiveness. The gain and PAE of the SSPA are 21.21 and 71%, respectively. There are also ways to reduce the size of the amplifier.
	Poster TUPAB350 [1.008 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB350
About •	paper received ※ 19 May 2021 paper accepted ※ 25 August 2021 issue date ※ 11 August 2021
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TUPAB351	The Progress of 300 kW Home-Made Fully Solid-State Transmitter for TPS	2328
	T.-C. Yu, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.D. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh NSRRC, Hsinchu, Taiwan
	To support the stable operation of Taiwan Photon Source (TPS) with 500mA beam current and the in-creasing beam line construction, a 3rd RF plant is thus constructed for such demand. The RF power source of the other 2 RF plants adopts klystron type transmitter and the 3rd RF plants is transferred to new technology of solid-state for better redundancy and easier mainte-nance. Base on the success of solid-state power ampli-fier development in 2020, a 3rd RF power source is thus decided to be made in house by solid-state tech-nology. The 500MHz 300kW solid-state transmitter is constructed by 4 80 kW solid-state power amplifier (SSPA) towers and power combined by 3 WR1800 3-dB hybrid couplers. Each tower is consisted of 110 850W final stage SSPA modules with 4 100W pre-amplifiers and 6 600W drive amplifiers. The pre and drive amplifiers are power combined for higher redun-dancy. The DC power are economical industrial 48V AC-DC rack mount power supplies which are parallel connected for higher total DC power and best redun-dancy. The architecture and present progress are pre-sented in this article.
	Poster TUPAB351 [2.348 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB351
About •	paper received ※ 20 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021
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TUPAB353	Remote Commissioning of 400 kW 352 MHz Amplifiers	2332
	C. Pasotti, A. Cuttin, A. Fabris Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy A. Frizzi, G. Zardi Itelco Broadcast Srl, Orvieto (TR), Italy M. Rossi DB Science, Padova, Italy
	In the framework of the European Spallation Source ERIC (ESS ERIC) In-Kind collaboration, Elettra Sincrotrone Trieste has the task to deliver 26 400 kW 352 MHz Radio Frequency Power Station (RFPS) units. They will feed the Spoke Cavities section of the proton Linac. The RFPS manufacturing contract has been awarded to the European Science Solutions consortium (ESS-C) gained the. The production of the amplifiers is well underway and it has reached a steady rate of delivery. Each RFPS is subject to a Factory Acceptance Test (FAT). In this contribution, the main results of the FATs are presented, together with the FAT remote session protocol. This protocol has been specifically developed to cope with the traveling and in persons meeting restrictions imposed by the COVID-19 pandemic.
	Poster TUPAB353 [2.675 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB353
About •	paper received ※ 17 May 2021 paper accepted ※ 23 June 2021 issue date ※ 17 August 2021
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TUPAB354	352-MHz Solid State RF System Development at the Advanced Photon Source	2335
	D. Horan, D.J. Bromberek, N.P. DiMonte, A. Goel, T.J. Madden, A. Nassiri, G. Trento, G.J. Waldschmidt ANL, Lemont, Illinois, USA
	Development effort is underway on a 352MHz, 200kW solid state rf system intended as the base design to replace the existing klystron-based rf systems presently in use at the Advanced Photon Source (APS). A sixteen-input, 200kW final combining cavity was designed, built, and successfully tested to 29kW CW in combiner mode, and to 200kW CW in back-feed mode, where an external klystron was used to transmit power into the combining cavity. A four-port waveguide combiner was also tested in both backfeed and combiner mode to 193kW and 26kW respectively. Slow and fast interlock systems were designed and implemented to support the testing process. An EPICS and Programmable Logic Controller (PLC)-based system was developed to control, communicate with, and monitor the rf amplifiers used in the combiner-mode test, and to monitor and log system performance parameters relating to the combining cavity. Low-level rf control of the cavity in 29kW combiner-mode operation was achieved using the existing APS analog low-level rf hardware. Test data and design details are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB354
About •	paper received ※ 18 May 2021 paper accepted ※ 31 May 2021 issue date ※ 19 August 2021
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TUPAB355	Design and Implementation of a Production Model Bias Tee	2339
	T.L. Larter, E. Gutierrez, S.H. Kim, D.G. Morris, J.T. Popielarski, T. Xu, S. Zhao FRIB, East Lansing, Michigan, USA
	Funding: This work is supported by the US Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University. The Facility for Rare Isotope Beams (FRIB) includes two types of half wave SC resonators (HWR) operating at 322MHz. The fundamental power couplers used to transmit RF power into the HWRs commonly suffer from multipacting which can result in long conditioning times. A bias tee can be used to apply a high voltage to the couplers to help alleviate multipacting. A production version of the bias tee was commissioned for use at FRIB. The bias tee went through several design revisions to diagnose and correct thermal dissipation issues. This paper will discuss details of design and challenges faced during production validation of the bias tee.
	Poster TUPAB355 [0.630 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB355
About •	paper received ※ 19 May 2021 paper accepted ※ 28 May 2021 issue date ※ 12 August 2021
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TUPAB356	Electron Beam Driven Cavities	2342
	M. Schuett, U. Ratzinger IAP, Frankfurt am Main, Germany
	State of the art high power feeder for RF cavities used as accelerators generally require RF amplifiers consisting of a vacuum tube, such as a klystron or Grid Tubes. In addition, a number of cost intensive RF auxiliary devices are needed: Modulator, waveguides, circulator, power dump and couplers. The equipment requires significant floor space within the linac building. Alternatively, we propose a direct driven system. Aμbunched electron beam is injected directly into the cavity. A high perveance bunched electron beam can be generated by a standard electron gun combined with a deflecting beam chopper, an off-the-shelf IOT or klystron, respectively. The pulse rate is determined by the resonance frequency of the cavity. The resonator hereby acts like the output cavity of a klystron: Within its propagation through the cavity the beam is decelerated increasing the stored energy of the accelerator. We present 3D particle PIC simulations evaluating the geometry and beam properties in order to optimize the coupling efficiency and cavity excitation of state-of-art CH particle accelerator structures. S. Setzer, T. Weiland and U. Ratzinger, A Chopped Electron Beam Driver for H-Type Cavities, 20th ‘International Linac Conference, Monterey, California, August 21-25, 2000, pp. 1001-1003
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB356
About •	paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 11 August 2021
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TUPAB357	Development of the X-Band Megawatt-Class Coaxial Magnetrons	2346
	J.Y. Liu, H.B. Chen, Y.S. Han, J. Shi, C.-X. Tang, C.J. Wang, J. Wang, H. Zha TUB, Beijing, People’s Republic of China
	X-band coaxial magnetrons are preferred for industrial and medical accelerators owing to the compact size, low cost and high efficiency. A conditioning and high power test stand for X-band magnetrons has been built in Tsinghua University. Two X-band magnetrons named "MGT-1#" and "MGT-2#" were tested at this stand. The maximum anode currents of both magnetrons reached 100 A after the conditioning process. Maximum peak output power of 1.71 MW and 1.89 MW was achieved for "MGT-1#" and "MGT-2#", respectively. The efficiencies of the two magnetrons are both about 50%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB357
About •	paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 28 August 2021
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TUPAB358	Novel 500 MHz Solid State Power Amplifier Module Development at Sirius	2349
	M.H. Wallner, R.H. Farias, A.P.B. Lima, F. Santiago de Oliveira LNLS, Campinas, Brazil
	A new solid state power amplifier (SSPA) module is being developed at the Brazilian Center for Research in Energy and Materials (CNPEM) to drive one of the superconducting RF cavities to be installed at Sirius, its new 3 GeV fourth generation synchrotron light source. Several prototypes have been built and tested in-house, and a planar balun was designed to achieve a push-pull configuration at deep class AB operation. Efforts to optimize heat exchange in various ways have been made. Results obtained thus far are presented and the next steps concerning development are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB358
About •	paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 19 August 2021
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WEPAB402	Status and Progress of the High-Power RF System for High Energy Photon Source	3653
	T.M. Huang, J. Li, H.Y. Lin, Y.L. Luo, Q. Ma, W.M. Pan, P. Zhang, F.C. Zhao IHEP, Beijing, People’s Republic of China
	Funding: Work was supported in part by High Energy Photon Source, a major national science and technology infrastructure in China, and in part by the National Natural Science Foundation of China(12075263). High Energy Photon Source is a 6-GeV diffraction-limited synchrotron light source currently under construction in Beijing. Three types of high-power RF systems are used to drive the booster and the storage ring. For the booster ring, a total of 600-kW continuous-wave (CW) RF power is generated by six 500-MHz solid-state power amplifiers (SSA) and fed into six normal-conducting copper cavities. Concerning the storage ring, five CW 260-kW SSAs at 166 MHz and two CW 260-kW SSAs at 500-MHz are used to drive five fundamental and two third-harmonic superconducting cavities respectively. The RF power distributions are realized by 9-3/16" rigid coaxial line for the 166-MHz system and EIA standard WR1800 waveguide for the 500-MHz one. High-power circulators and loads are installed at the outputs of all SSAs to further protect the power transmitters from damages due to reflected power although each amplifier module is equipped with individual isolators. The overall system layout and the progress of the main components are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB402
About •	paper received ※ 18 May 2021 paper accepted ※ 02 July 2021 issue date ※ 14 August 2021
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THXC07	Adaptive Control of Klystron Operation Parameters for Energy Saving at Storage Ring of TPS	3748
	T.-C. Yu, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.D. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh NSRRC, Hsinchu, Taiwan
	To satisfy maximum beam current operation in the storage ring of TPS, the operation parameters of both RF transmitters are set to be able to generate its maxi-mum RF power in daily usage. Under such condition, the klystrons can deliver any power below 300kW at constant AC power consumption which is about 520-530 kW. Hence, the AC power usage is independent of the required RF output power. To best utilize the avail-able AC power based on the required RF power, an adaptive control methodology is proposed here to change the operation parameters of the klystron, cath-ode voltage and anode voltage, according to the pre-sent RF power. The corresponding operation parame-ters are applied by the prior tested table which maps the operation parameters with the different saturation RF power. The test results show that the saved energy can be 32% to 11% from 30mA to 450mA for both RF plants as comparing to constant operation parameters of 1047 kW AC power.
	Slides THXC07 [1.241 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXC07
About •	paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 11 August 2021
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THPAB319	RF Power Generating System for the Linear Ion Accelerator	4417
	V.G. Kuzmichev, T. Kulevoy, D.A. Liakin, D.N. Selesnev, A. Sitnikov ITEP, Moscow, Russia M.L. Smetanin, A.V. Telnov, N.V. Zavyalov VNIIEF, Sarov, Russia
	An RF power supply system based on solid-state amplifiers has been developed for the linear accelerator of heavy ions. The report contains information on the characteristics and composition of the system, presents the LLRF structure for RFQ and DTL sections.
	Poster THPAB319 [0.275 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB319
About •	paper received ※ 16 May 2021 paper accepted ※ 16 August 2021 issue date ※ 19 August 2021
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THPAB336	Novel Magnetron Operation and Control Methods for Superconducting RF Accelerators	4442
	G.M. Kazakevich, R.P. Johnson Muons, Inc, Illinois, USA T.N. Khabiboulline, G.V. Romanov, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	High power magnetrons designed and optimized for industrial heating, being injection-locked, have been suggested to power superconducting RF cavities for accelerators due to lower cost and higher efficiency. However, standard operation methods do not provide high efficiency with wideband control suppressing microphonics. We have developed and experimentally verified novel methods of operating and controlling the magnetron that provide stable RF generation with higher efficiency and lower noise than other RF sources. By our method the magnetrons operate with the anode voltage notably lower than the self-excitation threshold improving its performance. This is also a promising way to increase tube reliability and longevity. A magnetron operating with the anode voltage lower than the self-excitation threshold, in so-called stimulated coherent generation mode has special advantage for pulse operation with a gated injection-locking signal. This eliminates the need for expensive pulsed HV modulators and additionally increases the magnetron RF source efficiency due to absence of losses in HV modulators.
	Poster THPAB336 [0.960 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB336
About •	paper received ※ 15 May 2021 paper accepted ※ 08 July 2021 issue date ※ 22 August 2021
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Paper

Title

Page

Availability Modeling of the Solid-State Power Amplifiers for the CERN SPS RF Upgrade

2308

L. Felsberger, A. Apollonio, T. Cartier-Michaud, E. Montesinos, J.C. Oliveira, J.A. Uythoven
CERN, Geneva, Switzerland

Funding: This project has received funding from the Euratom research and training programme 2019-2020 under grant agreement No 945077.
As part of the LHC Injector Upgrade program a complete overhaul of the Super Proton Synchrotron Radio-Frequency (RF) system took place. New cavities have been installed for which the solid-state technology was chosen to deliver a combined RF power of 2 MW from 2560 RF amplifiers. This strategy promises high availability as the system continues operation when some of the amplifiers fail. This study quantifies the operational availability that can be achieved with this new installation. The evaluation is based on a Monte Carlo simulation of the system using the novel AvailSim4 simulation software. A model based on lifetime estimations of the RF modules is compared against data from early operational experience. Sensitivity analyses have been made, that give insight to the chosen operational scenario. With the increasing use of solid-state RF power amplifiers, the findings of this study provide a useful reference for future application of this technology in particle accelerators.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB345

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paper received ※ 19 May 2021 paper accepted ※ 01 July 2021 issue date ※ 19 August 2021

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TUPAB346

Development of a 500-MHz 150-kW Solid-State Power Amplifier for High Energy Photon Source

2312

Y.L. Luo, T.M. Huang, J. Li, H.Y. Lin, Q. Ma, Q.Y. Wang, P. Zhang, F.C. Zhao
IHEP, Beijing, People’s Republic of China

A 500-MHz 150-kW solid-state power amplifier (SSA) has been developed to test the 500-MHz normal conducting cavities for High Energy Photon Source (HEPS) booster ring. It will also be used to power normal conducting cavities in the initial beam commissioning stage of the HEPS storage ring. A total number of 96 amplifier modules are combined initially by coaxial and later by waveguide combiners to deliver the 150-kW RF power. The final output is of EIA standard WR1800 rectangular waveguide. Each amplifier module consists four transistors equipped with individual circulator and load and outputs 2-kW RF power. Modularity, redundancy and satisfactory RF performance are demonstrated. In the final stage of HEPS project, this 150-kW amplifier will be modified to a 100-kW amplifier to join the other five 100-kW SSAs for normal operation of the booster cavities. The development and test results are presented in this paper.

Poster TUPAB346 [1.870 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB346

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 15 August 2021

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TUPAB347

Development of a 166-MHz 260-kW Solid-State Power Amplifier for High Energy Photon Source

2315

Y.L. Luo, T.M. Huang, J. Li, H.Y. Lin, Q. Ma, Q.Y. Wang, P. Zhang, F.C. Zhao
IHEP, Beijing, People’s Republic of China

166-MHz 260-kW solid-state power amplifiers have been chosen to drive the 166.6-MHz superconducting cavities for the storage ring of High Energy Photon Source. Highly modular yet compact are desired. A total number of 112 amplifier modules of 3 kW each are combined in a multi-stage power combining topology. The final output is of 9-3/16" 50 Ω coaxial rigid line. Each amplifier module consists of 3 LDMOS transistors with individual circulator and load. Thermal simulations of the amplifier module have been conducted to optimize cooling capabilities for both travelling-wave and full-reflection operation scenarios. High efficiency, sufficient redundancy and excellent RF performances of the 260-kW system are demonstrated. A control system is also integrated and EPICS is used to manage the monitored data. The design and test results of the amplifier system are presented in this paper.

Poster TUPAB347 [1.972 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB347

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 29 August 2021

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TUPAB348

Magnetron R&D for High Efficiency CW RF Sources for Industrial Accelerators

2318

H. Wang, K. Jordan, R.M. Nelson, R.A. Rimmer, S.O. Solomon
JLab, Newport News, Virginia, USA
B.R.L. Coriton, C.P. Moeller, K.A. Thackston
GA, San Diego, California, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177, and DOE OS/HEP Accelerator Stewardship award 2019-2021.
The scheme of using high-efficiency magnetrons to drive radiofrequency accelerators has been demonstrated at 2450 MHz in CW mode *. Magnetron test stands at JLab and GA have been set up to further test the noise figure and the locking speed of the injection phase-lock method. For higher power applications, power combining experiments using a TM010 cavity-type combiner and a magic tee for the binary combiner while using a single clean injection signal has been carried out at 2450 MHz. The frequency pulling effect between the magnetron and a low-Q cavity has been shown to enhance the frequency locking bandwidth compared to the injection phase-lock alone. The principle has been studied by the equivalent circuit simulation, analytical model, and finally confirmed experimentally on the magnetrons. Due to the pandemic delay in 2020, the equivalent high power tests using a 75kW, 915MHz industrial magnetron will be done in 2021 and will be reported in a future paper.
* H. Wang, et al, Magnetron R&Ds for High-Efficiency CW RF Sources of Particle Accelerators, WEXXPLS1, proceedings of IPAC 2019, Melbourne, Australia, May 19 -24, 2019.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB348

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paper received ※ 22 May 2021 paper accepted ※ 21 June 2021 issue date ※ 30 August 2021

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TUPAB349

High Efficiency, Low Cost RF Sources for Accelerators and Colliders

2322

R.L. Ives, T. Bui, G. Collins, H. Freund, T.W. Habermann, D. Marsden, M.E. Read
CCR, San Mateo, California, USA
B.E. Chase, J. Reid
Fermilab, Batavia, Illinois, USA
N. Chaudhary, J.R. Conant, T. Cox, R. Ho, C. McVey, C.M. Walker
CPI, Palo Alto, California, USA
J.C. Frisch, L. Ma
SLAC, Menlo Park, California, USA
A. Jensen
Leidos Corp, Billerica, MA, USA
J.M. Potter
JP Accelerator Works, Los Alamos, New Mexico, USA
W. Sessions
Georgia Tech Research Institute, Smyrna, Georgia, USA

Funding: U.S. Department of Energy
Calabazas Creek Research, Inc. (CCR) and its collaborators are developing high efficiency, low cost RF sources. Phase and Amplitude Controlled Magnetrons: CCR, Fermilab, and Communications & Power Industries, LLC (CPI) recently developed a 100 kW, 1.3 GHz magnetron system with amplitude and phase control. The system operated at more than 80% efficiency and demonstrated rapid control of amplitude and phase. Multiple Beam Triodes: CCR, in collaboration with CPI and JP Accelerator Works, Inc., is developing 200 kW, pulsed and CW RF sources from 350 to 700 MHz with projected efficiencies exceeding 80% and cost of $0.50/Watt. Prototype tubes are scheduled for tests in spring 2021. High Efficiency Klystrons:CCR, CPI, and Leidos, Inc. are building a 1.3 GHz, 100 kW klystron operating at 80% efficiency. High power testing is scheduled for summer 2021. Multiple Beam IOTs: CCR and Georgia Tech Research Institute are developing MBIOTs with simplified input coupling and high efficiency. Simulations indicate that 3rd harmonic drive power can increase the efficiency 8-10 %. The program is developing a prototype tube to produce 200 kW peak, 100 kW average power at 704 MHz.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB349

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paper received ※ 18 May 2021 paper accepted ※ 01 June 2021 issue date ※ 27 August 2021

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TUPAB350

Design of 71 MHz Power Amplifier in a Single-ended Architecture for IRANCYC-10 Cyclotron

2325

F. Babagoli Moziraji, H. Afarideh
AUT, Tehran, Iran
M. Dehghan
Shahid Beheshti University, Tehran, Iran
F. Ghasemi
NSTRI, Tehran, Iran

In this paper, the design and simulation of a high power amplifier to provide the required power of a cyclotron accelerator (IRANCYC-10) is presented step-by-step. By combining four modules of this amplifier, a power of 2.5 kW can be achieved to start the main power amplifier. The single ended designs amplifier can generate 1 kW the operating frequency of 71MHz continuous wave (CW). The purpose of choosing this type of design is simplicity to build without the need for a balun, low weight to build high power, as well as cost-effectiveness. The gain and PAE of the SSPA are 21.21 and 71%, respectively. There are also ways to reduce the size of the amplifier.

Poster TUPAB350 [1.008 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB350

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paper received ※ 19 May 2021 paper accepted ※ 25 August 2021 issue date ※ 11 August 2021

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TUPAB351

The Progress of 300 kW Home-Made Fully Solid-State Transmitter for TPS

2328

T.-C. Yu, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.D. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh
NSRRC, Hsinchu, Taiwan

To support the stable operation of Taiwan Photon Source (TPS) with 500mA beam current and the in-creasing beam line construction, a 3rd RF plant is thus constructed for such demand. The RF power source of the other 2 RF plants adopts klystron type transmitter and the 3rd RF plants is transferred to new technology of solid-state for better redundancy and easier mainte-nance. Base on the success of solid-state power ampli-fier development in 2020, a 3rd RF power source is thus decided to be made in house by solid-state tech-nology. The 500MHz 300kW solid-state transmitter is constructed by 4 80 kW solid-state power amplifier (SSPA) towers and power combined by 3 WR1800 3-dB hybrid couplers. Each tower is consisted of 110 850W final stage SSPA modules with 4 100W pre-amplifiers and 6 600W drive amplifiers. The pre and drive amplifiers are power combined for higher redun-dancy. The DC power are economical industrial 48V AC-DC rack mount power supplies which are parallel connected for higher total DC power and best redun-dancy. The architecture and present progress are pre-sented in this article.

Poster TUPAB351 [2.348 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB351

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paper received ※ 20 May 2021 paper accepted ※ 11 June 2021 issue date ※ 20 August 2021

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TUPAB353

Remote Commissioning of 400 kW 352 MHz Amplifiers

2332

C. Pasotti, A. Cuttin, A. Fabris
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. Frizzi, G. Zardi
Itelco Broadcast Srl, Orvieto (TR), Italy
M. Rossi
DB Science, Padova, Italy

In the framework of the European Spallation Source ERIC (ESS ERIC) In-Kind collaboration, Elettra Sincrotrone Trieste has the task to deliver 26 400 kW 352 MHz Radio Frequency Power Station (RFPS) units. They will feed the Spoke Cavities section of the proton Linac. The RFPS manufacturing contract has been awarded to the European Science Solutions consortium (ESS-C) gained the. The production of the amplifiers is well underway and it has reached a steady rate of delivery. Each RFPS is subject to a Factory Acceptance Test (FAT). In this contribution, the main results of the FATs are presented, together with the FAT remote session protocol. This protocol has been specifically developed to cope with the traveling and in persons meeting restrictions imposed by the COVID-19 pandemic.

Poster TUPAB353 [2.675 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB353

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paper received ※ 17 May 2021 paper accepted ※ 23 June 2021 issue date ※ 17 August 2021

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TUPAB354

352-MHz Solid State RF System Development at the Advanced Photon Source

2335

D. Horan, D.J. Bromberek, N.P. DiMonte, A. Goel, T.J. Madden, A. Nassiri, G. Trento, G.J. Waldschmidt
ANL, Lemont, Illinois, USA

Development effort is underway on a 352MHz, 200kW solid state rf system intended as the base design to replace the existing klystron-based rf systems presently in use at the Advanced Photon Source (APS). A sixteen-input, 200kW final combining cavity was designed, built, and successfully tested to 29kW CW in combiner mode, and to 200kW CW in back-feed mode, where an external klystron was used to transmit power into the combining cavity. A four-port waveguide combiner was also tested in both backfeed and combiner mode to 193kW and 26kW respectively. Slow and fast interlock systems were designed and implemented to support the testing process. An EPICS and Programmable Logic Controller (PLC)-based system was developed to control, communicate with, and monitor the rf amplifiers used in the combiner-mode test, and to monitor and log system performance parameters relating to the combining cavity. Low-level rf control of the cavity in 29kW combiner-mode operation was achieved using the existing APS analog low-level rf hardware. Test data and design details are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB354

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paper received ※ 18 May 2021 paper accepted ※ 31 May 2021 issue date ※ 19 August 2021

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TUPAB355

Design and Implementation of a Production Model Bias Tee

2339

T.L. Larter, E. Gutierrez, S.H. Kim, D.G. Morris, J.T. Popielarski, T. Xu, S. Zhao
FRIB, East Lansing, Michigan, USA

Funding: This work is supported by the US Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
The Facility for Rare Isotope Beams (FRIB) includes two types of half wave SC resonators (HWR) operating at 322MHz. The fundamental power couplers used to transmit RF power into the HWRs commonly suffer from multipacting which can result in long conditioning times. A bias tee can be used to apply a high voltage to the couplers to help alleviate multipacting. A production version of the bias tee was commissioned for use at FRIB. The bias tee went through several design revisions to diagnose and correct thermal dissipation issues. This paper will discuss details of design and challenges faced during production validation of the bias tee.

Poster TUPAB355 [0.630 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB355

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paper received ※ 19 May 2021 paper accepted ※ 28 May 2021 issue date ※ 12 August 2021

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TUPAB356

Electron Beam Driven Cavities

2342

M. Schuett, U. Ratzinger
IAP, Frankfurt am Main, Germany

State of the art high power feeder for RF cavities used as accelerators generally require RF amplifiers consisting of a vacuum tube, such as a klystron or Grid Tubes. In addition, a number of cost intensive RF auxiliary devices are needed: Modulator, waveguides, circulator, power dump and couplers. The equipment requires significant floor space within the linac building. Alternatively, we propose a direct driven system. Aμbunched electron beam is injected directly into the cavity. A high perveance bunched electron beam can be generated by a standard electron gun combined with a deflecting beam chopper*, an off-the-shelf IOT or klystron, respectively. The pulse rate is determined by the resonance frequency of the cavity. The resonator hereby acts like the output cavity of a klystron: Within its propagation through the cavity the beam is decelerated increasing the stored energy of the accelerator. We present 3D particle PIC simulations evaluating the geometry and beam properties in order to optimize the coupling efficiency and cavity excitation of state-of-art CH particle accelerator structures.
* S. Setzer, T. Weiland and U. Ratzinger, A Chopped Electron Beam Driver for H-Type Cavities, 20th ‘International Linac Conference, Monterey, California, August 21-25, 2000, pp. 1001-1003

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB356

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paper received ※ 19 May 2021 paper accepted ※ 21 June 2021 issue date ※ 11 August 2021

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TUPAB357

Development of the X-Band Megawatt-Class Coaxial Magnetrons

2346

J.Y. Liu, H.B. Chen, Y.S. Han, J. Shi, C.-X. Tang, C.J. Wang, J. Wang, H. Zha
TUB, Beijing, People’s Republic of China

X-band coaxial magnetrons are preferred for industrial and medical accelerators owing to the compact size, low cost and high efficiency. A conditioning and high power test stand for X-band magnetrons has been built in Tsinghua University. Two X-band magnetrons named "MGT-1#" and "MGT-2#" were tested at this stand. The maximum anode currents of both magnetrons reached 100 A after the conditioning process. Maximum peak output power of 1.71 MW and 1.89 MW was achieved for "MGT-1#" and "MGT-2#", respectively. The efficiencies of the two magnetrons are both about 50%.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB357

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paper received ※ 19 May 2021 paper accepted ※ 02 June 2021 issue date ※ 28 August 2021

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TUPAB358

Novel 500 MHz Solid State Power Amplifier Module Development at Sirius

2349

M.H. Wallner, R.H. Farias, A.P.B. Lima, F. Santiago de Oliveira
LNLS, Campinas, Brazil

A new solid state power amplifier (SSPA) module is being developed at the Brazilian Center for Research in Energy and Materials (CNPEM) to drive one of the superconducting RF cavities to be installed at Sirius, its new 3 GeV fourth generation synchrotron light source. Several prototypes have been built and tested in-house, and a planar balun was designed to achieve a push-pull configuration at deep class AB operation. Efforts to optimize heat exchange in various ways have been made. Results obtained thus far are presented and the next steps concerning development are discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB358

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paper received ※ 19 May 2021 paper accepted ※ 18 June 2021 issue date ※ 19 August 2021

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WEPAB402

Status and Progress of the High-Power RF System for High Energy Photon Source

3653

T.M. Huang, J. Li, H.Y. Lin, Y.L. Luo, Q. Ma, W.M. Pan, P. Zhang, F.C. Zhao
IHEP, Beijing, People’s Republic of China

Funding: Work was supported in part by High Energy Photon Source, a major national science and technology infrastructure in China, and in part by the National Natural Science Foundation of China(12075263).
High Energy Photon Source is a 6-GeV diffraction-limited synchrotron light source currently under construction in Beijing. Three types of high-power RF systems are used to drive the booster and the storage ring. For the booster ring, a total of 600-kW continuous-wave (CW) RF power is generated by six 500-MHz solid-state power amplifiers (SSA) and fed into six normal-conducting copper cavities. Concerning the storage ring, five CW 260-kW SSAs at 166 MHz and two CW 260-kW SSAs at 500-MHz are used to drive five fundamental and two third-harmonic superconducting cavities respectively. The RF power distributions are realized by 9-3/16" rigid coaxial line for the 166-MHz system and EIA standard WR1800 waveguide for the 500-MHz one. High-power circulators and loads are installed at the outputs of all SSAs to further protect the power transmitters from damages due to reflected power although each amplifier module is equipped with individual isolators. The overall system layout and the progress of the main components are presented in this paper.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB402

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paper received ※ 18 May 2021 paper accepted ※ 02 July 2021 issue date ※ 14 August 2021

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THXC07

Adaptive Control of Klystron Operation Parameters for Energy Saving at Storage Ring of TPS

3748

T.-C. Yu, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.D. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh
NSRRC, Hsinchu, Taiwan

To satisfy maximum beam current operation in the storage ring of TPS, the operation parameters of both RF transmitters are set to be able to generate its maxi-mum RF power in daily usage. Under such condition, the klystrons can deliver any power below 300kW at constant AC power consumption which is about 520-530 kW. Hence, the AC power usage is independent of the required RF output power. To best utilize the avail-able AC power based on the required RF power, an adaptive control methodology is proposed here to change the operation parameters of the klystron, cath-ode voltage and anode voltage, according to the pre-sent RF power. The corresponding operation parame-ters are applied by the prior tested table which maps the operation parameters with the different saturation RF power. The test results show that the saved energy can be 32% to 11% from 30mA to 450mA for both RF plants as comparing to constant operation parameters of 1047 kW AC power.

Slides THXC07 [1.241 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THXC07

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paper received ※ 19 May 2021 paper accepted ※ 06 July 2021 issue date ※ 11 August 2021

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THPAB319

RF Power Generating System for the Linear Ion Accelerator

4417

V.G. Kuzmichev, T. Kulevoy, D.A. Liakin, D.N. Selesnev, A. Sitnikov
ITEP, Moscow, Russia
M.L. Smetanin, A.V. Telnov, N.V. Zavyalov
VNIIEF, Sarov, Russia

An RF power supply system based on solid-state amplifiers has been developed for the linear accelerator of heavy ions. The report contains information on the characteristics and composition of the system, presents the LLRF structure for RFQ and DTL sections.

Poster THPAB319 [0.275 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB319

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paper received ※ 16 May 2021 paper accepted ※ 16 August 2021 issue date ※ 19 August 2021

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THPAB336

Novel Magnetron Operation and Control Methods for Superconducting RF Accelerators

4442

G.M. Kazakevich, R.P. Johnson
Muons, Inc, Illinois, USA
T.N. Khabiboulline, G.V. Romanov, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

High power magnetrons designed and optimized for industrial heating, being injection-locked, have been suggested to power superconducting RF cavities for accelerators due to lower cost and higher efficiency. However, standard operation methods do not provide high efficiency with wideband control suppressing microphonics. We have developed and experimentally verified novel methods of operating and controlling the magnetron that provide stable RF generation with higher efficiency and lower noise than other RF sources. By our method the magnetrons operate with the anode voltage notably lower than the self-excitation threshold improving its performance. This is also a promising way to increase tube reliability and longevity. A magnetron operating with the anode voltage lower than the self-excitation threshold, in so-called stimulated coherent generation mode has special advantage for pulse operation with a gated injection-locking signal. This eliminates the need for expensive pulsed HV modulators and additionally increases the magnetron RF source efficiency due to absence of losses in HV modulators.

Poster THPAB336 [0.960 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB336

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paper received ※ 15 May 2021 paper accepted ※ 08 July 2021 issue date ※ 22 August 2021

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