This paper details the development and testing of the first working prototype of the S-band high-power klystron,accomplished at the Budker Institute of Nuclear Physics,Siberian Branch,Russian Academy of Sciences(BINP ...This paper details the development and testing of the first working prototype of the S-band high-power klystron,accomplished at the Budker Institute of Nuclear Physics,Siberian Branch,Russian Academy of Sciences(BINP SB RAS).Upon testing,the klystron demonstrated the following parameters:an operating frequency of 2856 MHz and a peak power output of 50 MW.The paper presents the klystron's design,its constituent units,and pertinent processing procedures,along with discussions on the measurement of its parameters.展开更多
This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the f...This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the future plan of circular electron–positron collider（CEPC） project. The RF window which is used in the klystron output section has a function to separate the klystron from the inner vacuum side to the outside, and high RF power propagates through the window with small power dissipation. Therefore, the window is a key component for the high power klystron. However, it is vulnerable to the high thermal stress and multipacting, so this paper presents the window design and analysis for these problems. The microwave design has been performed by using the computer simulation technology（CST） microwave studio and the return loss of the window has been established to be less than-90 d B. The multipacting simulation of the window has been carried out using MultiPac and CST particles studio. Through the multipacting analysis, it is shown that with thin coating of TiN, the multipacting effect has been suppressed effectively on the ceramic surface. The thermal analysis is carried out using ANSYS code and the temperature of alumina ceramic is lower than 310 K with water cooling.The design result successfully meets the requirement of the CEPC 650 MHz klystron. The manufacturing and high power test plan are also described in this paper.展开更多
To reduce the energy demand and operation cost for circular electron positron collider(CEPC), the high efficiency klystrons are being developed at Institute of High Energy Physics, Chinese Academy of Sciences. A 800-k...To reduce the energy demand and operation cost for circular electron positron collider(CEPC), the high efficiency klystrons are being developed at Institute of High Energy Physics, Chinese Academy of Sciences. A 800-k W continuous wave(CW) klystron operating at frequency of 650-MHz has been designed. The results of beam–wave interaction simulation with several different codes are presented. The efficiency is optimized to be 65% with a second harmonic cavity in three-dimensional(3D) particle-in-cell code CST. The effect of cavity frequency error and mismatch load on efficiency of klystron have been investigated. The design and cold test of reentrant cavities are described, which meet the requirements of RF section design. So far, the manufacturing and high-power test of the first klystron prototype have been completed.When the gun operated at DC voltage of 80 k V and current of 15.4 A, the klystron peak power reached 804 k W with output efficiency of about 65.3% at 40% duty cycle. The 1-d B bandwidth is ±0.8 MHZ. Due to the crack of ceramic window, the CW power achieved about 700 kW. The high-power test results are in good agreement with 3D simulation.展开更多
This letter reports the development of a 50MW S-band klystron in the Institute of Electronics, Chinese Academy of Sciences （IECAS）. It adopted a structure of six-cavity and single output window. Under conditions of ...This letter reports the development of a 50MW S-band klystron in the Institute of Electronics, Chinese Academy of Sciences （IECAS）. It adopted a structure of six-cavity and single output window. Under conditions of an RF （Radio Frequency） pulse width of 4t, ts, a beam voltage of 305,9kV and a beam current of 368A, the peak output power has achieved 51.4MW with an efficiency of 45.6% and a gain of 54dB.展开更多
The paper introduces the -35 kV/200 kW high voltage power supply (HVPS) which is specially used to test klystron units in LHCD system. The new klystrons must be tested under high voltage level before operation and the...The paper introduces the -35 kV/200 kW high voltage power supply (HVPS) which is specially used to test klystron units in LHCD system. The new klystrons must be tested under high voltage level before operation and the old klystrons which have worked for a longtime must be exercised by HVPS in lower hybrid current drive (LHCD) system. As the former HVPS has some shortages in engineering design and operation design, the HVPS has to be modified and rebuilt by adopting new method and technology to solve existing bottle-neck problems.展开更多
Two methods for improving the equidriving power-frequency characteristics of broad-band high power klystrons are presented. One is that a comb-line bandpass filter with someattenuation properties is inserted between t...Two methods for improving the equidriving power-frequency characteristics of broad-band high power klystrons are presented. One is that a comb-line bandpass filter with someattenuation properties is inserted between the TWT driver and the klystron for compensatingthe gain-frequency characteristics of the klystron to get the required equidriving power-frequencycharacteristics. The other is that a reactive element is connected with the input cavity to changeits resonance frequencies f<sub>0</sub> and Q<sub>L</sub>, and thus to improve the power-frequency characteristics ofthe klystron.展开更多
The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandw...The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandwidth synthetically.As a part of beam-wave interaction section,buncher section is simulated by Particle-In-Cell(PIC) code to observe the bunching process of electron beam to achieve high conversion efficiency of electron beam and RF field.When it comes to the other part,output circuit is designed as a three-section filter by an output cavity loaded with Chebyshev filter,and the cold test results are given.The beam-wave interaction is simulated by EGUN code and Arsenal-MSU code respectively.The simulated results indicated that,the existence of power dips in the operating bandwidth is verified by Arsenal-MSU code,comparing proper results by EGUN code.Then,the method that design parameters are not adjusted except parameters of buncher cavities to remove potential power dips is described.What is more,the simulated results of electron optics system are given by EGUN code and Arsenal-MSU code respectively.The further hot test results of klystron prove that the whole design of beam-wave interaction is effective.展开更多
This paper describes a high security data transmission system over X-band microwave frequency. The paper has two parts. The first part deals with encryption of binary data by Advanced Encryption Standard (AES) using V...This paper describes a high security data transmission system over X-band microwave frequency. The paper has two parts. The first part deals with encryption of binary data by Advanced Encryption Standard (AES) using VHDL modeling of Field Programmable Gate Array (FPGA). The second part deals with a novel idea of transmitting the encrypted data by using a single klystron. This requires the simultaneous generation of a pair of two independent RF frequencies from a reflex klystron working for X-band frequency range. In this scheme, the klystron is suitably biased on the repeller terminal and superimposed on a train of AES encrypted binary data so as to create two RF frequencies one corresponding to negative peaks and the other one to the positive peaks of the data resulting in an Frequency Shift Keying (FSK) signal. The results have been verified experimentally.展开更多
文摘This paper details the development and testing of the first working prototype of the S-band high-power klystron,accomplished at the Budker Institute of Nuclear Physics,Siberian Branch,Russian Academy of Sciences(BINP SB RAS).Upon testing,the klystron demonstrated the following parameters:an operating frequency of 2856 MHz and a peak power output of 50 MW.The paper presents the klystron's design,its constituent units,and pertinent processing procedures,along with discussions on the measurement of its parameters.
基金Project supported by Yifang Wang’s Science Studio of the Ten Thousand Talents Project,China
文摘This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the future plan of circular electron–positron collider（CEPC） project. The RF window which is used in the klystron output section has a function to separate the klystron from the inner vacuum side to the outside, and high RF power propagates through the window with small power dissipation. Therefore, the window is a key component for the high power klystron. However, it is vulnerable to the high thermal stress and multipacting, so this paper presents the window design and analysis for these problems. The microwave design has been performed by using the computer simulation technology（CST） microwave studio and the return loss of the window has been established to be less than-90 d B. The multipacting simulation of the window has been carried out using MultiPac and CST particles studio. Through the multipacting analysis, it is shown that with thin coating of TiN, the multipacting effect has been suppressed effectively on the ceramic surface. The thermal analysis is carried out using ANSYS code and the temperature of alumina ceramic is lower than 310 K with water cooling.The design result successfully meets the requirement of the CEPC 650 MHz klystron. The manufacturing and high power test plan are also described in this paper.
基金Project supported by Yifang Wang’s Science Studio of the Ten Thousand Talents Project。
文摘To reduce the energy demand and operation cost for circular electron positron collider(CEPC), the high efficiency klystrons are being developed at Institute of High Energy Physics, Chinese Academy of Sciences. A 800-k W continuous wave(CW) klystron operating at frequency of 650-MHz has been designed. The results of beam–wave interaction simulation with several different codes are presented. The efficiency is optimized to be 65% with a second harmonic cavity in three-dimensional(3D) particle-in-cell code CST. The effect of cavity frequency error and mismatch load on efficiency of klystron have been investigated. The design and cold test of reentrant cavities are described, which meet the requirements of RF section design. So far, the manufacturing and high-power test of the first klystron prototype have been completed.When the gun operated at DC voltage of 80 k V and current of 15.4 A, the klystron peak power reached 804 k W with output efficiency of about 65.3% at 40% duty cycle. The 1-d B bandwidth is ±0.8 MHZ. Due to the crack of ceramic window, the CW power achieved about 700 kW. The high-power test results are in good agreement with 3D simulation.
文摘This letter reports the development of a 50MW S-band klystron in the Institute of Electronics, Chinese Academy of Sciences （IECAS）. It adopted a structure of six-cavity and single output window. Under conditions of an RF （Radio Frequency） pulse width of 4t, ts, a beam voltage of 305,9kV and a beam current of 368A, the peak output power has achieved 51.4MW with an efficiency of 45.6% and a gain of 54dB.
基金The project supported by the Meg-Science Engineering Project of Chinese Academy of Sciences
文摘The paper introduces the -35 kV/200 kW high voltage power supply (HVPS) which is specially used to test klystron units in LHCD system. The new klystrons must be tested under high voltage level before operation and the old klystrons which have worked for a longtime must be exercised by HVPS in lower hybrid current drive (LHCD) system. As the former HVPS has some shortages in engineering design and operation design, the HVPS has to be modified and rebuilt by adopting new method and technology to solve existing bottle-neck problems.
文摘Two methods for improving the equidriving power-frequency characteristics of broad-band high power klystrons are presented. One is that a comb-line bandpass filter with someattenuation properties is inserted between the TWT driver and the klystron for compensatingthe gain-frequency characteristics of the klystron to get the required equidriving power-frequencycharacteristics. The other is that a reactive element is connected with the input cavity to changeits resonance frequencies f<sub>0</sub> and Q<sub>L</sub>, and thus to improve the power-frequency characteristics ofthe klystron.
文摘The paper mainly presents the design of beam-wave interaction of a C-band high-peakpower high-efficiency broadband klystron.The beam-wave interaction section is designed based on considerations of efficiency and bandwidth synthetically.As a part of beam-wave interaction section,buncher section is simulated by Particle-In-Cell(PIC) code to observe the bunching process of electron beam to achieve high conversion efficiency of electron beam and RF field.When it comes to the other part,output circuit is designed as a three-section filter by an output cavity loaded with Chebyshev filter,and the cold test results are given.The beam-wave interaction is simulated by EGUN code and Arsenal-MSU code respectively.The simulated results indicated that,the existence of power dips in the operating bandwidth is verified by Arsenal-MSU code,comparing proper results by EGUN code.Then,the method that design parameters are not adjusted except parameters of buncher cavities to remove potential power dips is described.What is more,the simulated results of electron optics system are given by EGUN code and Arsenal-MSU code respectively.The further hot test results of klystron prove that the whole design of beam-wave interaction is effective.
文摘This paper describes a high security data transmission system over X-band microwave frequency. The paper has two parts. The first part deals with encryption of binary data by Advanced Encryption Standard (AES) using VHDL modeling of Field Programmable Gate Array (FPGA). The second part deals with a novel idea of transmitting the encrypted data by using a single klystron. This requires the simultaneous generation of a pair of two independent RF frequencies from a reflex klystron working for X-band frequency range. In this scheme, the klystron is suitably biased on the repeller terminal and superimposed on a train of AES encrypted binary data so as to create two RF frequencies one corresponding to negative peaks and the other one to the positive peaks of the data resulting in an Frequency Shift Keying (FSK) signal. The results have been verified experimentally.
