Gabriel M. Rebeiz, Yong Guo, D. Rutledge, D. Kasilingam
A two-dimensional horn imaging array has been demonstrated at 242 GHz. In this configuration, a dipole is suspended in a pyramidal horn on a 1-μm silicon-oxynitride membrane. This approach leaves room for low-frequency lines and processing electronics. Pattern measurements agree well with theory, and show no sidelobes and 3-dB beamwidth of 35° and 46° for the E and H planes respectively. Possible application areas include superconducting tunnel-junction receivers for radio astronomy and imaging arrays for plasma diagnostics and radiometry.
{"title":"Two-dimensional horn imaging arrays","authors":"Gabriel M. Rebeiz, Yong Guo, D. Rutledge, D. Kasilingam","doi":"10.1117/12.943977","DOIUrl":"https://doi.org/10.1117/12.943977","url":null,"abstract":"A two-dimensional horn imaging array has been demonstrated at 242 GHz. In this configuration, a dipole is suspended in a pyramidal horn on a 1-μm silicon-oxynitride membrane. This approach leaves room for low-frequency lines and processing electronics. Pattern measurements agree well with theory, and show no sidelobes and 3-dB beamwidth of 35° and 46° for the E and H planes respectively. Possible application areas include superconducting tunnel-junction receivers for radio astronomy and imaging arrays for plasma diagnostics and radiometry.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130304906","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}
Qinsong Wang, A. T. Lin, N. Luhmann, D. Mcdermott, Kwo Ray Chu
Recent theoretical work has found conditions for stable operation of a CARM amplifier(1). The magnetic field should be somewhat less than βc = Ωc for stability, but considerably greater than the gyro-TWT grazing condition for higher efficiency due to autoresonance and higher frequency due to a Doppler upshift. The design of a 3 MW, 560 GHz CARM amplifier is presented.
{"title":"Cyclotron autoresonant maser (carm) ec heating source for high field tokamaks","authors":"Qinsong Wang, A. T. Lin, N. Luhmann, D. Mcdermott, Kwo Ray Chu","doi":"10.1117/12.951805","DOIUrl":"https://doi.org/10.1117/12.951805","url":null,"abstract":"Recent theoretical work has found conditions for stable operation of a CARM amplifier(1). The magnetic field should be somewhat less than βc = Ωc for stability, but considerably greater than the gyro-TWT grazing condition for higher efficiency due to autoresonance and higher frequency due to a Doppler upshift. The design of a 3 MW, 560 GHz CARM amplifier is presented.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130369658","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 : 1987-12-01DOI: 10.1109/irmm.1987.9126961
W. Manheimer, A. Fliflet, R. Lee
The quasi-optical gyrotron is a possible rf source for electron cyclotron resonances heating of large fusion reactors. To fully exploit its potential, a sheet beam electron gun should be utilized. A schematic and the parameters of the sheet beam gun are shown in Fig. 1. The gun shown is a magnetron injection gun modified for planar geometry. It actually produces a double sheet beam since up-down symmetry is assumed. In terms of the parameters of the beam in the gun, the gun parameters1 are derived for the parameters shown by conservation of canonical momentum, adiabatic compression in the presence of a voltage drop Vo-Va. The initial transverse energy comes from E × B motion in the voltage drop Va. Limiting currents are determined by the current being a small fraction of the space charge limiting current, and also by the current being able to propagate through the interaction region. Both of these limiting currents turn out to be expressed in terms of a current per unit length rather than total current. Thus, by making the emitting region long enough, the gun is capable of putting out arbitrary current. The focusing electrode shapes can be determined by electrode synthesis, modified to a planar configuration.2 The remaining issue is of edge losses. We show that the electrode synthesis technique can be modified to shape edge electrodes in such a way as to minimize edge effects. Results for such an electron gun design will be shown. This work was supported by the Department of Energy.
{"title":"Design considerations for a sheet beam electron gun for the quasi-optical gyrotron","authors":"W. Manheimer, A. Fliflet, R. Lee","doi":"10.1109/irmm.1987.9126961","DOIUrl":"https://doi.org/10.1109/irmm.1987.9126961","url":null,"abstract":"The quasi-optical gyrotron is a possible rf source for electron cyclotron resonances heating of large fusion reactors. To fully exploit its potential, a sheet beam electron gun should be utilized. A schematic and the parameters of the sheet beam gun are shown in Fig. 1. The gun shown is a magnetron injection gun modified for planar geometry. It actually produces a double sheet beam since up-down symmetry is assumed. In terms of the parameters of the beam in the gun, the gun parameters1 are derived for the parameters shown by conservation of canonical momentum, adiabatic compression in the presence of a voltage drop Vo-Va. The initial transverse energy comes from E × B motion in the voltage drop Va. Limiting currents are determined by the current being a small fraction of the space charge limiting current, and also by the current being able to propagate through the interaction region. Both of these limiting currents turn out to be expressed in terms of a current per unit length rather than total current. Thus, by making the emitting region long enough, the gun is capable of putting out arbitrary current. The focusing electrode shapes can be determined by electrode synthesis, modified to a planar configuration.2 The remaining issue is of edge losses. We show that the electrode synthesis technique can be modified to shape edge electrodes in such a way as to minimize edge effects. Results for such an electron gun design will be shown. This work was supported by the Department of Energy.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130404170","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 : 1987-12-01DOI: 10.1109/irmm.1987.9127079
W. Lawson, J. Calame, B. Hogan, W. Wang, D. Welsh, P. Latham, H. Heikkinen, M. Read, C. Striffler, V. L. Granatsteln
The feasibility of using gyroklystrons in linear collider applications is currently under investigation at the University of Maryland.1 We are constructing a four-cavity X-band tube which is predicted to achieve a peak power of 30–50 MW in 1–2 us pulses with an efficiency of 45% and a gain of 63 dB. This goal represents an increase in the state-of-the-art by three orders of magnitude in power2 and is close to predicted collider requirements.
{"title":"Final design and initial operation of a high peak power x-band gyroklystron","authors":"W. Lawson, J. Calame, B. Hogan, W. Wang, D. Welsh, P. Latham, H. Heikkinen, M. Read, C. Striffler, V. L. Granatsteln","doi":"10.1109/irmm.1987.9127079","DOIUrl":"https://doi.org/10.1109/irmm.1987.9127079","url":null,"abstract":"The feasibility of using gyroklystrons in linear collider applications is currently under investigation at the University of Maryland.1 We are constructing a four-cavity X-band tube which is predicted to achieve a peak power of 30–50 MW in 1–2 us pulses with an efficiency of 45% and a gain of 63 dB. This goal represents an increase in the state-of-the-art by three orders of magnitude in power2 and is close to predicted collider requirements.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"50 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114010334","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 : 1987-12-01DOI: 10.1109/irmm.1987.9126923
W. Morgan, K. Stephan
A novel technique for phase control in millimeter-wave phased arrays has been demonstrated with a 10 GHz model. The main beam of a four-element array has been steered ±5° using only one phase shifter. The system's characteristics such as an effective radiated power of 7.4 W, a sidelobe level 16 dB below the main beam, and adaptability to monolithic fabrication make this technique attractive for beam steering at millimeter wave frequencies.
{"title":"Inter-injection locking — a novel phase control technique for monolithic phased arrays","authors":"W. Morgan, K. Stephan","doi":"10.1109/irmm.1987.9126923","DOIUrl":"https://doi.org/10.1109/irmm.1987.9126923","url":null,"abstract":"A novel technique for phase control in millimeter-wave phased arrays has been demonstrated with a 10 GHz model. The main beam of a four-element array has been steered ±5° using only one phase shifter. The system's characteristics such as an effective radiated power of 7.4 W, a sidelobe level 16 dB below the main beam, and adaptability to monolithic fabrication make this technique attractive for beam steering at millimeter wave frequencies.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121717543","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 : 1987-12-01DOI: 10.1109/irmm.1987.9126887
M. Afsar
Dielectric measurement techniques developed over last twelve years are reviewed. Varieties of measurement techniques are necessary in order to cope with material problems such as absorption characteristics, size and thickness, shape and temperature and frequency coverage. Precision data are now required on absorption coefficient, refractive index, real and imaginary parts of dielectric permittivity and loss tangent for varieties of classes of materials over a wide frequency range for applications such as substrate, window and lens material, as dielectric waveguide, quarter wave plates, insulators and in integrated circuitry.
{"title":"Precision millimeter and submillimeter wave measurements of material properties","authors":"M. Afsar","doi":"10.1109/irmm.1987.9126887","DOIUrl":"https://doi.org/10.1109/irmm.1987.9126887","url":null,"abstract":"Dielectric measurement techniques developed over last twelve years are reviewed. Varieties of measurement techniques are necessary in order to cope with material problems such as absorption characteristics, size and thickness, shape and temperature and frequency coverage. Precision data are now required on absorption coefficient, refractive index, real and imaginary parts of dielectric permittivity and loss tangent for varieties of classes of materials over a wide frequency range for applications such as substrate, window and lens material, as dielectric waveguide, quarter wave plates, insulators and in integrated circuitry.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131751503","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 : 1987-12-01DOI: 10.1109/irmm.1987.9126990
T. Bigelow, T. White, H. Kimrey
The Advanced Toroidal Facility (ATF) Electron Cyclotron Heating (ECH) system presently under construction will consist of two 53.2-GHz, 200-kW continuous-wave (cw) gyrotrons with a mode-controlled waveguide system and polarized launcher optimized for maximum power in the ATF plasma. Several components, such as a waveguide mode-analyzing directional coupler, a TiO2 mode absorber, miter bends, and a polarization-selectable beamed launcher, have been developed and tested. Laboratory results and initial high-power operation of the system are presented.
{"title":"Atf ech waveguide component development and testing","authors":"T. Bigelow, T. White, H. Kimrey","doi":"10.1109/irmm.1987.9126990","DOIUrl":"https://doi.org/10.1109/irmm.1987.9126990","url":null,"abstract":"The Advanced Toroidal Facility (ATF) Electron Cyclotron Heating (ECH) system presently under construction will consist of two 53.2-GHz, 200-kW continuous-wave (cw) gyrotrons with a mode-controlled waveguide system and polarized launcher optimized for maximum power in the ATF plasma. Several components, such as a waveguide mode-analyzing directional coupler, a TiO2 mode absorber, miter bends, and a polarization-selectable beamed launcher, have been developed and tested. Laboratory results and initial high-power operation of the system are presented.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"42 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131826371","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 : 1987-12-01DOI: 10.1109/irmm.1987.9127078
B. James, I. Falconer, M. Bowden, L. Whitbourn, P. Stimson, J. Macfarlane
An optically pumped HCOOH laser has been operated simultaneously on three cascade rotational transitions. This leads to enhanced output power for all three transitions. The application of this mode of operation to interferometry is described.
{"title":"Simultaneous triple cascade operation of optically pumped submillimeter lasers","authors":"B. James, I. Falconer, M. Bowden, L. Whitbourn, P. Stimson, J. Macfarlane","doi":"10.1109/irmm.1987.9127078","DOIUrl":"https://doi.org/10.1109/irmm.1987.9127078","url":null,"abstract":"An optically pumped HCOOH laser has been operated simultaneously on three cascade rotational transitions. This leads to enhanced output power for all three transitions. The application of this mode of operation to interferometry is described.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130851106","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 : 1987-12-01DOI: 10.1109/irmm.1987.9127039
H. Jory, K. Felch, E. Jongewaard
A typical double disc window geometry is described for a CW millimeter-wave gyrotron. The desired microwave and mechanical properties for the two discs and for the coolant material are discussed. Sample thermal and mechanical calculations are presented for a 200 kW CW 60 GHz window design. The measured peak temperature for the same window is given for comparison.
{"title":"Material requirements for gyrotron windows","authors":"H. Jory, K. Felch, E. Jongewaard","doi":"10.1109/irmm.1987.9127039","DOIUrl":"https://doi.org/10.1109/irmm.1987.9127039","url":null,"abstract":"A typical double disc window geometry is described for a CW millimeter-wave gyrotron. The desired microwave and mechanical properties for the two discs and for the coolant material are discussed. Sample thermal and mechanical calculations are presented for a 200 kW CW 60 GHz window design. The measured peak temperature for the same window is given for comparison.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127622050","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 : 1987-12-01DOI: 10.1109/irmm.1987.9126935
Q. Wang, T. Kho, A. T. Lin, D. Mcdermott, N. Luhmann
The growth rate and efficiency of a general traveling wave interaction (TWI) can be significantly enhanced by selectively suppressing those electrons which are phased to gain energy from the wave. We have observed in simulations of a particular TWI, a cyclotron autoresonant maser (CARM), the increase of efficiency by a factor of three and growth rate by two.
{"title":"A gyroresonant phase filter for the enhancement of traveling wave gain and efficiency","authors":"Q. Wang, T. Kho, A. T. Lin, D. Mcdermott, N. Luhmann","doi":"10.1109/irmm.1987.9126935","DOIUrl":"https://doi.org/10.1109/irmm.1987.9126935","url":null,"abstract":"The growth rate and efficiency of a general traveling wave interaction (TWI) can be significantly enhanced by selectively suppressing those electrons which are phased to gain energy from the wave. We have observed in simulations of a particular TWI, a cyclotron autoresonant maser (CARM), the increase of efficiency by a factor of three and growth rate by two.","PeriodicalId":399243,"journal":{"name":"1987 Twelth International Conference on Infrared and Millimeter Waves","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1987-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114669234","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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