Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746989
M. S. Chauhan, P. K. Jain
In this paper the study of electron bunching in the output cavity of gyroklystron has been carried out to optimize the output efficiency of gyroklystron by numerically solving the coupled equations obtained from nonlinear analysis, describing the strong interaction between the beam and RF fields in the output cavity of the gyroklystron. The generalized results obtained here can be applied to optimize the output efficiency of a gyroklystron of any frequency and power.
{"title":"Study of electron bunching in gyroklystrons","authors":"M. S. Chauhan, P. K. Jain","doi":"10.1109/IVEC.2011.5746989","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746989","url":null,"abstract":"In this paper the study of electron bunching in the output cavity of gyroklystron has been carried out to optimize the output efficiency of gyroklystron by numerically solving the coupled equations obtained from nonlinear analysis, describing the strong interaction between the beam and RF fields in the output cavity of the gyroklystron. The generalized results obtained here can be applied to optimize the output efficiency of a gyroklystron of any frequency and power.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"1990 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125506519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746886
M. Aloisio, P. Angeletti, S. D'addio
In this paper, statistical techniques for the determination of Isolation Performance of Multiport Amplifiers are described and their critical comparison is discussed. Different approaches are considered and their results are compared from an end user perspective.
{"title":"Statistical characterization of Isolation Performance of Multiport Amplifiers: A critical discussion","authors":"M. Aloisio, P. Angeletti, S. D'addio","doi":"10.1109/IVEC.2011.5746886","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746886","url":null,"abstract":"In this paper, statistical techniques for the determination of Isolation Performance of Multiport Amplifiers are described and their critical comparison is discussed. Different approaches are considered and their results are compared from an end user perspective.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131815705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746934
T. Bui, M. Read, L. Ives
This paper will describe the new feature, temporal particle-in-cell analysis in Beam Optics Analyzer in detail. Algorithms for pushing particles and field solution will be discussed. Numerical results for a diode as well as a gridded electron gun will demonstrate the implementation.
{"title":"Temporal particle-in-cell analysis in Beam Optics Analyzer","authors":"T. Bui, M. Read, L. Ives","doi":"10.1109/IVEC.2011.5746934","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746934","url":null,"abstract":"This paper will describe the new feature, temporal particle-in-cell analysis in Beam Optics Analyzer in detail. Algorithms for pushing particles and field solution will be discussed. Numerical results for a diode as well as a gridded electron gun will demonstrate the implementation.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131933712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746881
A. Grede, H. Henke
Today, numerical simulations are an inherent part of the design process of electron vacuum tubes. By now, a number of PIC codes have been developed which allow for the simulation of complete electron tubes. However, due to their long calculation times these codes are not a good choice at the beginning of a design process or for the quick inspection of a new idea. Moreover, there are a lot of structures which can only be adequately modeled by a very fine mesh, resulting in an extremely small time step and therefore in an inconvienent simulation time. The particle tracker presented in this paper shows, that there is not always the need for an expensive high performance code or a large computer cluster. For a lot of problems, satisfying results can be achieved much faster by a simple code.
{"title":"QPT, a simple particle tracker for tube simulation","authors":"A. Grede, H. Henke","doi":"10.1109/IVEC.2011.5746881","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746881","url":null,"abstract":"Today, numerical simulations are an inherent part of the design process of electron vacuum tubes. By now, a number of PIC codes have been developed which allow for the simulation of complete electron tubes. However, due to their long calculation times these codes are not a good choice at the beginning of a design process or for the quick inspection of a new idea. Moreover, there are a lot of structures which can only be adequately modeled by a very fine mesh, resulting in an extremely small time step and therefore in an inconvienent simulation time. The particle tracker presented in this paper shows, that there is not always the need for an expensive high performance code or a large computer cluster. For a lot of problems, satisfying results can be achieved much faster by a simple code.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128396853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746945
Z. Geng, Yi-nong Su, Pu-kun Liu, Shi-Chang Zhang, W. Gu, Shou-xi Xu, Zhi-Chao Zeng
In this paper, the design of the conventional electron beam spreading system of the gyrotron collector consisted of the magnetic shade and two pairs of coils is presented. The simulation and experiment of the electron beam distribution on the collector wall of the gyrotron applied to the electron spreading system is completed.
{"title":"Study of the collector of W-band gyrotron","authors":"Z. Geng, Yi-nong Su, Pu-kun Liu, Shi-Chang Zhang, W. Gu, Shou-xi Xu, Zhi-Chao Zeng","doi":"10.1109/IVEC.2011.5746945","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746945","url":null,"abstract":"In this paper, the design of the conventional electron beam spreading system of the gyrotron collector consisted of the magnetic shade and two pairs of coils is presented. The simulation and experiment of the electron beam distribution on the collector wall of the gyrotron applied to the electron spreading system is completed.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122315832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5747054
Y. Liu, L. Tai, Shih-Hung Chen, L. Ang, W. Koh
Two-dimensional electromagnetic (EM) particle-in-cell simulations were performed to study the effect of the displacement current and the self-magnetic field on the space-charge limited current density or the Child-Langmuir law of a short-pulse electron flow with a propagation distance of ζ and an emitting width of W from the classical regime to the relativistic regime. Numerical scaling of the two-dimensional electromagnetic Child-Langmuir (CL) law was constructed, and it scales with (ζ / W) and (ζ / W)2 at the classical and relativistic regimes, respectively. Our findings reveal that the displacement current can considerably enhance the space-charge limited (SCL) current density as compared to the well-known two-dimensional electrostatic (ES) Child-Langmuir law even at the classical regime.
{"title":"Two-dimensional electromagnetic Child-Langmuir law of a short-pulse electron flow","authors":"Y. Liu, L. Tai, Shih-Hung Chen, L. Ang, W. Koh","doi":"10.1109/IVEC.2011.5747054","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5747054","url":null,"abstract":"Two-dimensional electromagnetic (EM) particle-in-cell simulations were performed to study the effect of the displacement current and the self-magnetic field on the space-charge limited current density or the Child-Langmuir law of a short-pulse electron flow with a propagation distance of ζ and an emitting width of W from the classical regime to the relativistic regime. Numerical scaling of the two-dimensional electromagnetic Child-Langmuir (CL) law was constructed, and it scales with (ζ / W) and (ζ / W)2 at the classical and relativistic regimes, respectively. Our findings reveal that the displacement current can considerably enhance the space-charge limited (SCL) current density as compared to the well-known two-dimensional electrostatic (ES) Child-Langmuir law even at the classical regime.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129913196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746849
S. Chattopadhyay
John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society.
{"title":"Microwaves and particle accelerators: A fundamental link","authors":"S. Chattopadhyay","doi":"10.1109/IVEC.2011.5746849","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746849","url":null,"abstract":"John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134569714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746895
S. M. Chung
Carbon nanotube (CNT) cathode is considered a hopeful new cathode for various vacuum electronics devices, and the most important specifications are turn-on field and current density. One factor that affects turn-on field most is the Schottky barrier between CNT and the metal electrode in CNT cathode. We manage to reduce this barrier by using metal-CNT hot-bonding process and found the turn-on field improved to 1–2 V/μm. Current density is found related to microscopic shielding effect, and the heating results to shifting of emission sites, thus a lowered average current density and fluctuation in emission current.
{"title":"On the turn-on field of carbon nanotube cathode","authors":"S. M. Chung","doi":"10.1109/IVEC.2011.5746895","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746895","url":null,"abstract":"Carbon nanotube (CNT) cathode is considered a hopeful new cathode for various vacuum electronics devices, and the most important specifications are turn-on field and current density. One factor that affects turn-on field most is the Schottky barrier between CNT and the metal electrode in CNT cathode. We manage to reduce this barrier by using metal-CNT hot-bonding process and found the turn-on field improved to 1–2 V/μm. Current density is found related to microscopic shielding effect, and the heating results to shifting of emission sites, thus a lowered average current density and fluctuation in emission current.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130857268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746965
C. Du, Pu‐Kun Liu, Q. Xue, Shi-Chang Zhang
This paper presents the development of a fundamental harmonic TE01 mode W-band gyrotron backward-wave oscillator (Gyro-BWO). The MIG employs a triode configuration to generate a helical electron beam with the current of 1.5 A, the voltage of 30 kV, and a pitch factor of 1.0. A mode-converter free reflective cavity is employed. Simulation reveals that the TE01 mode reflective cavity is capable of generating highest output power up to 10.7 kW with a tunable 3dB bandwidth of about 4 GHz. The present system is aiming at providing a 3kW average power in a tunable bandwidth of 3GHz around 94GHz.
{"title":"Development of a W-band gyrotron backward wave oscillator","authors":"C. Du, Pu‐Kun Liu, Q. Xue, Shi-Chang Zhang","doi":"10.1109/IVEC.2011.5746965","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746965","url":null,"abstract":"This paper presents the development of a fundamental harmonic TE01 mode W-band gyrotron backward-wave oscillator (Gyro-BWO). The MIG employs a triode configuration to generate a helical electron beam with the current of 1.5 A, the voltage of 30 kV, and a pitch factor of 1.0. A mode-converter free reflective cavity is employed. Simulation reveals that the TE01 mode reflective cavity is capable of generating highest output power up to 10.7 kW with a tunable 3dB bandwidth of about 4 GHz. The present system is aiming at providing a 3kW average power in a tunable bandwidth of 3GHz around 94GHz.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133366478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-21DOI: 10.1109/IVEC.2011.5746878
T. Bui, L. Ives, M. Read
This paper will describe the new capability in BOA, the heat transfer integration with particle simulations. It will discuss implemented techniques to smooth the wall power density field generated by electron energy. It will explain the finite element method with adaptivity used to solve the heat equation, and provide numerical results to demonstrate the implementation.
{"title":"Heat transfer integration with Beam Optics Analyzer","authors":"T. Bui, L. Ives, M. Read","doi":"10.1109/IVEC.2011.5746878","DOIUrl":"https://doi.org/10.1109/IVEC.2011.5746878","url":null,"abstract":"This paper will describe the new capability in BOA, the heat transfer integration with particle simulations. It will discuss implemented techniques to smooth the wall power density field generated by electron energy. It will explain the finite element method with adaptivity used to solve the heat equation, and provide numerical results to demonstrate the implementation.","PeriodicalId":106174,"journal":{"name":"2011 IEEE International Vacuum Electronics Conference (IVEC)","volume":"32 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114010936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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