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Szabatin Jerzy - One of the best experts on this subject based on the ideXlab platform.
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A Model Based Fast Protection System for High Power RF Tube Amplifiers Used at the European XFEL Accelerator
IEEE, 2018Co-Authors: Butkowski Lukasz, Vogel Vladimir, Schlarb Holger, Szabatin JerzyAbstract:The driving engine of the superconducting accelerator of the European X-ray free electron laser (XFEL) is a set of 27 radio frequency (RF) stations. Each of the underground RF stations consists of a multibeam horizontal Klystron that can provide up to 10 MW of power at 1.3 GHz. Klystrons are sensitive devices with a limited lifetime and a high mean time between failures. In real operation, the lifetime of the tube can be significantly reduced because of failures. The special fast protection Klystron lifetime management (KLM) system has been developed to minimize the influence of service conditions on the lifetime of Klystrons. The main task of this system is to detect all events which can destroy the tube as quickly as possible, and switch off the driving RF signal or the high voltage. Detection of events is based on a comparison of the value of the real signal obtained at the system output with the value estimated on the basis of a high-power RF amplifier model and input signals. The KLM system has been realized in field-programmable gate array (FPGA) and implemented in XFEL. Implementation is based on the standard low-level RF micro telecommunications computing architecture (MTCA.4 or xTCA). The main part of the paper focuses on an estimation of the Klystron model and the implementation of KLM in FPGA. The results of the performance of the KLM system will also be presented
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Model Based Fast Protection System for High Power RF Tube Amplifiers Used at European XFEL Accelerator
2016Co-Authors: Butkowski Lukasz, Vogel Vladimir, Schlarb Holger, Szabatin JerzyAbstract:The driving engine of the superconducting accelerator of the European X-ray Free-Electron Laser (XFEL) are 27 Radio Frequency (RF) stations. Each of an underground RF station consists from multi-beam horizontal Klystron which can provide up to 10MW of power at 1.3GHz. Klystrons are sensitive devices with limited lifetime and high mean time between failures. In the real operation the lifetime of the tube can be thoroughly reduced by failures. To minimize the influence of service conditions to the Klystrons lifetime the special fast protection system named as Klystron Lifetime Management System (KLM) has been developed. The main task of this system is to detect all events which can destroy the tube as quickly as possible and switch off driving signal. Detection of events is based on comparison of model of high power RF amplifier with real signals. All algorithms are implemented in Field Programmable Gate Array (FPGA). For the XFEL implementation of KLM is based on the standard Low Level RF (LLRF) Mi-cro TCA technology (MTCA.4 or xTCA).This article focus on the Klystron model estimation for protection system and implementation of KLM in FPGA on MTCA.4 architecture
Igor Syratchev - One of the best experts on this subject based on the ideXlab platform.
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modeling of coupled cell output structures for the Klystrons
IEEE Transactions on Electron Devices, 2019Co-Authors: Igor SyratchevAbstract:High-frequency, high-power Klystrons proved to be significant for application in compact particle accelerators, high-resolution radars, and fast data communication systems. As most of the linear beam devices, the performance of the Klystron deteriorates progressively with an increasing operating frequency due to the reduction of individual RF cavity impedances. Coupled cell structures can alleviate such degradation by extending the beam–wave interaction region. The accurate simulation of the Klystron with the coupled cell structure relies on the resources and the time-consuming particle-in-cell (PIC) codes. To speed up the Klystron design process, the coupled-mode theory was carefully reviewed and extended to facilitate the calculation of the complex spectra of the arbitrarily coupled cavity system and its interaction with the bunched electron beam. These new methods were implemented in the large signal Klystron simulation code KlyC. The design and optimization of the Ku -band, low-voltage Klystron is explained as a demonstration of the new technique’s effectiveness. The KlyC simulations have been thoroughly benchmarked with the CST PIC code and both codes showed a good (within 1%) agreement, while KlyC is significantly (about 100 times) faster.
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klyc 1 5 d large signal simulation code for Klystrons
IEEE Transactions on Plasma Science, 2019Co-Authors: Igor SyratchevAbstract:The High Efficiency International Klystron Activity (HEIKA) was initiated at CERN in 2014 to evaluate and develop new Klystron bunching technologies for high-efficiency Klystrons in application to the large-scale scientific projects such as the Compact Linear Collider (CLIC) and the Future Circular Collider (FCC). The success of such development strongly depends on the availability of the specialized Klystron computer codes. Unfortunately, the accurate and efficient 2-D large-signal codes are proprietary and are not freely available to the wide Klystron community. The new 1.5-D Klystron code called KlyC has been developed as an attempt to bridge the gap between fast, but approximate 1-D models and time/resources consuming particle-in-cell (PIC) codes. KlyC simulates the specific physical processes such as the current emission from the metal surface, the space charge depression along the Klystron, and the residual RF current modulation of the spent beam. KlyC internal eigenmode solver allows fast simulations of the 2-D complex electromagnetic (EM) field in the axis-symmetrical cavity with the arbitrary cavity profile. The internal KlyC optimizer module can help the designer to speed up the Klystron development process. In this paper, the theoretical model, general review of the code performance, and benchmarking between KlyC, AJDisk/1-D, PIC code MAGIC/2-D, and CST/3-D are presented using FCC Klystrons as an example.
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scaling procedures and post optimization for the design of high efficiency Klystrons
IEEE Transactions on Electron Devices, 2019Co-Authors: Igor SyratchevAbstract:A semianalytical parametric scaling procedure (PSP) for Klystron design has been developed. The PSP allows existing Klystron designs to be scaled to different operating frequencies, beam power, and perveance, while maintaining the electron bunching and deceleration processes. For the fixed layout of a Klystron RF circuit, the PSP provides parameters of the scaled Klystron which are nearly optimal. The theoretical background and step by step derivation of the scaling principles are presented. The effectiveness of the PSP is shown through a generic five-cavity L-band Klystron.
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toward high power Klystrons with rf power conversion efficiency on the order of 90
IEEE Transactions on Electron Devices, 2015Co-Authors: Andrey Yu Baikov, Chiara Marrelli, Igor SyratchevAbstract:The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF Klystrons operates in the electronic efficiency range between 40% and 55%. Only a few Klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF power conversion efficiency in a Klystron amplifier is presented. The essential part of this method is a new bunching technique—bunching with bunch core oscillations. Computer simulations confirm that the RF production efficiency above 90% can be reached with this new bunching method. The results of a preliminary study of an $L$ -band, 20-MW peak RF power multibeam Klystron for Compact Linear Collider with the efficiency above 85% are presented.
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high power microwave pulse compression of Klystrons by phase modulation of high q storage cavities
2004Co-Authors: R Bossart, Igor Syratchev, P Brown, J Mourier, L TannerAbstract:At the CERN linear electron accelerators LIL and CTF, the peak RF power from the 3GHzKlystrons was doubled by means of LIPS microwave pulse compressors. To produce constant RF power from the cavity-based pulse compressors, the Klystrons were driven by a fast RF-phase modulation program. For the CLIC Test Facility CTF3, a new type of a Barrel Open Cavity (BOC) with a high quality factor Q0 has been developed. Contrary to LIPS with two resonant cavities, BOC operates with a single cavity supporting two orthogonal resonant modes TM 10,1,1 in the same cavity. For both LIPS and BOC storage cavities, it is important that the RF power reflected back to the Klystron is minimal. This implies that the resonant frequencies, Q-factors and coupling factors of the two resonant modes of a pulse compressor are closely matched, and that the resonant frequencies are accurate to within a few KHz. The effects of small differences between the two orthogonal modes of the BOC cavity have been investigated. The dynamic pulse response of a Klystron and LIPS pulse compressor has been measured for fast phase modulation. The high power tests have demonstrated that the compressed RF power was doubled and reached 70 MW during 1.5 µs. The power amplitude was stabilized to within ±1% by the feed-forward phase correction program, and the measured phase sag of the compressed output pulse was 8°, as predicted by the theory.
GEORGE CARYOTAKIS - One of the best experts on this subject based on the ideXlab platform.
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latest results in slac 75 mw ppm Klystrons
Prepared for 7th Workshop on High Energy Density and High Power RF Kalamata Greece 13-17 Jun 2005, 2006Co-Authors: Daryl Sprehn, Erik Jongewaard, A Haase, L. St-laurent, C Pearson, GEORGE CARYOTAKIS, R PhillipsAbstract:75 MW X-band Klystrons utilizing Periodic Permanent Magnet (PPM) focusing have been undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC) for almost nine years. The Klystron development has been geared toward realizing the necessary components for the construction of the Next Linear Collider (NLC). The PPM devices built to date which fit this class of operation consist of a variety of 50 MW and 75 MW devices constructed by SLAC, KEK (Tsukuba, Japan) and industry. All these tubes follow from the successful SLAC design of a 50 MW PPM Klystron in 1996. In 2004 the latest two Klystrons were constructed and tested with preliminary results reported at EPAC2004. The first of these two devices was tested to the full NLC specifications of 75 MW, 1.6 microseconds pulse length, and 120 Hz. This 14.4 kW average power operation came with a tube efficiency >50%. The most recent testing of these last two devices will be presented here. Design and manufacturing issues of the latest Klystron, due to be tested by the Fall of 2005, are also discussed.
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latest results in slac 75 mw ppm Klystrons
Prepared for 7th Workshop on High Energy Density and High Power RF Kalamata Greece 13-17 Jun 2005, 2006Co-Authors: Daryl Sprehn, Erik Jongewaard, A Haase, L. St-laurent, GEORGE CARYOTAKIS, C PearsonAbstract:75 MW X-band Klystrons utilizing Periodic Permanent Magnet (PPM) focusing have been undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC) for almost nine years. The Klystron development has been geared toward realizing the necessary components for the construction of the Next Linear Collider (NLC). The PPM devices built to date which fit this class of operation consist of a variety of 50 MW and 75 MW devices constructed by SLAC, KEK (Tsukuba, Japan) and industry. All these tubes follow from the successful SLAC design of a 50 MW PPM Klystron in 1996. In 2004 the latest two Klystrons were constructed and tested with preliminary results reported at EPAC2004. The first of these two devices was tested to the full NLC specifications of 75 MW, 1.6 microseconds pulse length, and 120 Hz. This 14.4 kW average power operation came with a tube efficiency >50%. The most recent testing of these last two devices will be presented here. Design and manufacturing issues of the latest Klystron, due to be tested by the Fall of 2005, are also discussed.
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high power Klystrons theory and practice at the stanford linear accelerator centerpart i
2004Co-Authors: GEORGE CARYOTAKISAbstract:This is Part I of a two-part report on design and manufacturing methods used at SLAC to produce accelerator Klystrons. Chapter 1 begins with the history and applications for Klystrons, in both of which Stanford University was extensively involved. The remaining chapters review the theory of Klystron operation, derive the principal formulae used in their design, and discuss the assumptions that they involve. These formulae are subsequently used in small-signal calculations of the frequency response of a particular Klystron, whose performance is also simulated by two different computer codes. The results of calculations and simulations are compared to the actual performance of the Klystron.
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x band Klystron development at the stanford linear accelerator center
Proceedings of SPIE the International Society for Optical Engineering, 2000Co-Authors: Daryl Sprehn, Erik Jongewaard, GEORGE CARYOTAKIS, R Phillips, Arnold VlieksAbstract:X-band Klystrons capable of 75 MW and utilizing either solenoidal or Periodic Permanent Magnet (PPM) focusing are undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC). The Klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). SLAC has completed a solenoidal-focused X-band Klystron development effort to study the design and operation of tubes with beam microperveances of 1.2. As of early 2000, nine 1.2 (mu) K Klystrons have been tested to 50 MW at 1.5 microsecond(s) . The first 50 MW PPM Klystron, constructed in 1996, was designed with a 0.6 (mu) K beam at 465 kV and uses a 5-cell traveling-wave output structure. Recent testing of this tube at wider pulsewidths has reached 50 MW at 55% efficiency, 2.4 microsecond(s) and 60 Hz. A 75 MW PPM Klystron prototype was constructed in 1998 and has reached the NLC design target of 75 MW at 1.5 microsecond(s) . A new 75 MW PPM Klystron design, which is aimed at reducing the cost and increasing the reliability of multi- megawatt PPM Klystrons, is under investigation. The tube is scheduled for testing during early 2001.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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the future of Klystrons
International Vacuum Electronics Conference, 2000Co-Authors: GEORGE CARYOTAKISAbstract:Summary form only given, as follows. The Klystron is the oldest of the microwave tubes, but continues to be essential to a number of user communities, principally that of experimental physics, which was also responsible for its invention. The advent of traveling-wave tubes and of the transistor has limited the uses of the Klystron to applications requiring a high pf/sup 2/ product. For those applications, it remains the amplifier of choice, particularly if cost is considered. The paper describes some new Klystron configurations and their potential future. These include multi-beam and sheet-beam Klystrons, PPM Klystrons, and millimeter-wave Klystrons, mass-produced with lithographic techniques.
Butkowski Lukasz - One of the best experts on this subject based on the ideXlab platform.
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A Model Based Fast Protection System for High Power RF Tube Amplifiers Used at the European XFEL Accelerator
IEEE, 2018Co-Authors: Butkowski Lukasz, Vogel Vladimir, Schlarb Holger, Szabatin JerzyAbstract:The driving engine of the superconducting accelerator of the European X-ray free electron laser (XFEL) is a set of 27 radio frequency (RF) stations. Each of the underground RF stations consists of a multibeam horizontal Klystron that can provide up to 10 MW of power at 1.3 GHz. Klystrons are sensitive devices with a limited lifetime and a high mean time between failures. In real operation, the lifetime of the tube can be significantly reduced because of failures. The special fast protection Klystron lifetime management (KLM) system has been developed to minimize the influence of service conditions on the lifetime of Klystrons. The main task of this system is to detect all events which can destroy the tube as quickly as possible, and switch off the driving RF signal or the high voltage. Detection of events is based on a comparison of the value of the real signal obtained at the system output with the value estimated on the basis of a high-power RF amplifier model and input signals. The KLM system has been realized in field-programmable gate array (FPGA) and implemented in XFEL. Implementation is based on the standard low-level RF micro telecommunications computing architecture (MTCA.4 or xTCA). The main part of the paper focuses on an estimation of the Klystron model and the implementation of KLM in FPGA. The results of the performance of the KLM system will also be presented
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Model Based Fast Protection System for High Power RF Tube Amplifiers Used at European XFEL Accelerator
2016Co-Authors: Butkowski Lukasz, Vogel Vladimir, Schlarb Holger, Szabatin JerzyAbstract:The driving engine of the superconducting accelerator of the European X-ray Free-Electron Laser (XFEL) are 27 Radio Frequency (RF) stations. Each of an underground RF station consists from multi-beam horizontal Klystron which can provide up to 10MW of power at 1.3GHz. Klystrons are sensitive devices with limited lifetime and high mean time between failures. In the real operation the lifetime of the tube can be thoroughly reduced by failures. To minimize the influence of service conditions to the Klystrons lifetime the special fast protection system named as Klystron Lifetime Management System (KLM) has been developed. The main task of this system is to detect all events which can destroy the tube as quickly as possible and switch off driving signal. Detection of events is based on comparison of model of high power RF amplifier with real signals. All algorithms are implemented in Field Programmable Gate Array (FPGA). For the XFEL implementation of KLM is based on the standard Low Level RF (LLRF) Mi-cro TCA technology (MTCA.4 or xTCA).This article focus on the Klystron model estimation for protection system and implementation of KLM in FPGA on MTCA.4 architecture
Vogel Vladimir - One of the best experts on this subject based on the ideXlab platform.
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A Model Based Fast Protection System for High Power RF Tube Amplifiers Used at the European XFEL Accelerator
IEEE, 2018Co-Authors: Butkowski Lukasz, Vogel Vladimir, Schlarb Holger, Szabatin JerzyAbstract:The driving engine of the superconducting accelerator of the European X-ray free electron laser (XFEL) is a set of 27 radio frequency (RF) stations. Each of the underground RF stations consists of a multibeam horizontal Klystron that can provide up to 10 MW of power at 1.3 GHz. Klystrons are sensitive devices with a limited lifetime and a high mean time between failures. In real operation, the lifetime of the tube can be significantly reduced because of failures. The special fast protection Klystron lifetime management (KLM) system has been developed to minimize the influence of service conditions on the lifetime of Klystrons. The main task of this system is to detect all events which can destroy the tube as quickly as possible, and switch off the driving RF signal or the high voltage. Detection of events is based on a comparison of the value of the real signal obtained at the system output with the value estimated on the basis of a high-power RF amplifier model and input signals. The KLM system has been realized in field-programmable gate array (FPGA) and implemented in XFEL. Implementation is based on the standard low-level RF micro telecommunications computing architecture (MTCA.4 or xTCA). The main part of the paper focuses on an estimation of the Klystron model and the implementation of KLM in FPGA. The results of the performance of the KLM system will also be presented
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Model Based Fast Protection System for High Power RF Tube Amplifiers Used at European XFEL Accelerator
2016Co-Authors: Butkowski Lukasz, Vogel Vladimir, Schlarb Holger, Szabatin JerzyAbstract:The driving engine of the superconducting accelerator of the European X-ray Free-Electron Laser (XFEL) are 27 Radio Frequency (RF) stations. Each of an underground RF station consists from multi-beam horizontal Klystron which can provide up to 10MW of power at 1.3GHz. Klystrons are sensitive devices with limited lifetime and high mean time between failures. In the real operation the lifetime of the tube can be thoroughly reduced by failures. To minimize the influence of service conditions to the Klystrons lifetime the special fast protection system named as Klystron Lifetime Management System (KLM) has been developed. The main task of this system is to detect all events which can destroy the tube as quickly as possible and switch off driving signal. Detection of events is based on comparison of model of high power RF amplifier with real signals. All algorithms are implemented in Field Programmable Gate Array (FPGA). For the XFEL implementation of KLM is based on the standard Low Level RF (LLRF) Mi-cro TCA technology (MTCA.4 or xTCA).This article focus on the Klystron model estimation for protection system and implementation of KLM in FPGA on MTCA.4 architecture