Electron cyclotron emission imaging(ECEI)is a critical diagnostic tool for measuring two-dimensional electron temperature fluctuations.The optical system,a key component of the ECEI diagnostic,determines the spatial r...Electron cyclotron emission imaging(ECEI)is a critical diagnostic tool for measuring two-dimensional electron temperature fluctuations.The optical system,a key component of the ECEI diagnostic,determines the spatial resolution,field of view,and imaging performance of electron temperature fluctuations.In this study,comprehensive laboratory tests and characterizations of the optical system,including the local oscillator(LO)coupling optics and the radio frequency(RF)receiving optics,were conducted to ensure optimal performance during plasma discharge experiments.Laboratory testing of the LO optics revealed that the light intensity at the edge channels reaches 36%of that at the central channels;however,both are sufficient to effectively drive the down-converted mixers.The RF optics focus covers the entire non-harmonic overlap region,corresponding to a normalized plasma minor radius range of ρ=−0.2 to 0.9,and offers three zoom modes:narrow,medium,and wide,with poloidal resolutions of 1.5 cm,1.8 cm,and 2.1 cm,respectively.The characterizations for these zoom modes align well with the optical design specifications.It was observed that the imaging surfaces of all zoom modes are exceptionally flat,indicating high-quality ECEI measurements with excellent spatial resolution.The LO lens,focusing lens,and zoom adjustment lens are capable of remote independent control,which enhances the operational flexibility of the system.Preliminary analyses conducted with the ECEI system successfully captured the two-dimensional structure and spatiotemporal evolution of phenomena such as sawtooth crashes,demonstrating the robust capability of the system to provide valuable insights into plasma dynamics.展开更多
An improved method for analyzing the radiation characteristic of the quasi-optical launcher is presented. The launcher is decomposed into an open-ended waveguide and a helical cut according to the proposed method. The...An improved method for analyzing the radiation characteristic of the quasi-optical launcher is presented. The launcher is decomposed into an open-ended waveguide and a helical cut according to the proposed method. The radiation from the open-ended waveguide is obtained by using the Stratton-Chu formulation. The helical cut＇s radiation is calculated based on its current distribution, gained by several iterative computations, which helps to improve the calculation accuracy since the diffraction effect introduced by the helical cut is considered during the calculation. The proposed method is used to study different launches, and the results are compared with the existing results. Good agreement is achieved between the results obtained from our proposed method and the reported results. The present results provide an alternative for analysis and synthesis of the optical-mode converter.展开更多
We introduce an asymmetrical mirror design to a 140 GHz TE_（22,6） quasi-optical（QO） mode converter system to correct the asymmetry of the beam＇s field distribution caused by the Denisov launcher. By such optimiza...We introduce an asymmetrical mirror design to a 140 GHz TE_（22,6） quasi-optical（QO） mode converter system to correct the asymmetry of the beam＇s field distribution caused by the Denisov launcher. By such optimization, the output beam with better symmetrical distribution is obtained at the system＇s output window. Based on the calculated results,the QO mode converter system＇s performance is already satisfying without iterative phase correction. Scalar and vector correlation coefficients between the output beam and the fundamental Gaussian beam are respectively 98.4% and 93.0%,while the total power transmission efficiency of the converter system is 94.4%. The assistance of optical ray tracing to the design of such QO mode converters is introduced and discussed as well.展开更多
The principle and design method of Denisov-type quasi-optical mode converter is investigated indetail.The operation process of the Denisov-type launcher is analyzed by applying the geometrical optics,andthe Gaussian-l...The principle and design method of Denisov-type quasi-optical mode converter is investigated indetail.The operation process of the Denisov-type launcher is analyzed by applying the geometrical optics,andthe Gaussian-like field distribution achieved on the waveguide wall is also derived.The method for designing arippled-wall launcher is proposed on the basis of coupled mode theory.A simulation code for Denisov-type qua-si-optical mode converter GQOMC-D is developed based on coupled mode theory,vector diffraction integrationand physical optics,which is compared to the design parameters and experimental results reported in literaturefor its validity.According to this code,a Denisov-type quasi-optical mode converter used in 110 GHz TE22.6mode gyrotron oscillators is designed.Simulation results indicate that a Gaussian-like beam is obtained at theoutput window with a scalar content of 98.4%and a conversion efficiency of 94.7%.展开更多
The accurate power measurement is important for an ECRH system in tokamak.The dummy load is designed and developed for the measurement of the millimeter wave power.This work analyzes the dummy load based on the quasi-...The accurate power measurement is important for an ECRH system in tokamak.The dummy load is designed and developed for the measurement of the millimeter wave power.This work analyzes the dummy load based on the quasi-optical method and the ray tracing method.The reflectivity and thermal deposition of the dummy load have been considered to ensure the safety of the entire system.High-power tests have been carried out at a 105 GHz/500 kW ECRH system.The results of the tests indicate that the designed dummy load is stable and valid.展开更多
The electromagnetic field integral equation in the quasi-optical cavity is obtained using the dyadic Green’s function. An expression is derived for the input impedance of a single microstrip patch cavity excited by a...The electromagnetic field integral equation in the quasi-optical cavity is obtained using the dyadic Green’s function. An expression is derived for the input impedance of a single microstrip patch cavity excited by a coaxial probe using moment method. The input impedance of a rectangular microstrip patch is discussed with this method. The result of this paper is similar to that of the microstrip antenna. This paper is of very important value for designing microstrip quasi-optical oscillator.展开更多
A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The ...A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The powerful optical design software ZEMAX was utilized to design the contours of the lens, and numerical method based on ray tracing and Huygens’ Principle was processed to verify the design result. Measurement result shows that the 3 dB width of the beam spot formed by the lens is 34 mm at distance of 3460 mm, and the beam pattern on imaging plane are equally arranged and the intensity decreases only 0.55 dB while the object lateral deviation increases to 300 mm.展开更多
A novel quasi-opitcal resonance system modified axisymmetrical quasi-optical cavity of oblique ratation(MAQCOR)-is proposed using the laplace integral transormation the kinetic theory of the high relativsitic electron...A novel quasi-opitcal resonance system modified axisymmetrical quasi-optical cavity of oblique ratation(MAQCOR)-is proposed using the laplace integral transormation the kinetic theory of the high relativsitic electron cyclotron maser with MAQCORis carried out within the framowrk of the linearized vlasov-mxawel eauations the formulas of beamwave intreaction power starting current and frequency shift have been derived some important plroblems such as high-order harmonic modes competition inflneces of the rationg angle and space charge and space chrage effcet are andlyaed and discussed in detall and a serios fo new condinsions are obtained a theoretical bssia is laid for the design of this novel qussi-optical gyrotron展开更多
This study contributes to renewable energy policy modeling by developing a dynamic decision-making framework that incorporates uncertainty,irreversibility,and the value of information.It responds to the growing need f...This study contributes to renewable energy policy modeling by developing a dynamic decision-making framework that incorporates uncertainty,irreversibility,and the value of information.It responds to the growing need for structured tools to guide investments amid climate volatility,technological change,and economic risk.Grounded in decision theory—especially the work of Von Neumann,Morgenstern,and Savage—the framework models renewable energy investments using subjective probabilities and quasi-option value under evolving climate conditions.The empirical component focuses on ARAMCO’s renewable energy strategy,a corporate case illustrating how fossil-fuel-dependent entities can pivot toward sustainability.The analysis uses Net Present Value(NPV)modeling and real options analysis under different discount rates and carbon pricing scenarios to assess financial feasibility.Results show that lower discount rates and moderate carbon prices improve investment attractiveness,while high carbon pricing significantly reduces project viability.The study also highlights the policy relevance of this framework.Government subsidies,adaptive regulation,and public-private partnerships emerge as critical enablers of resilient investments.It further suggests that aligning ESG reporting standards with carbon pricing policies can strengthen market signals and encourage private capital flow into renewables.By integrating theoretical modeling with corporate investment realities,this chapter offers a replicable tool for policymakers and investors.Future research should expand its application across sectors and geographies to validate generalizability and improve planning in the transition toward low-carbon economies.展开更多
We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion...We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion loss less than 0.4 dB, and separation between adjacent channels more than 20 dB for either TE or TM incidence. Firstly, we briefly introduce the disadvantages of two types of FSS filter： waveguide-array FSS and printed FSS, which are commonly employed in the millimeter and sub-millimeter wave band. In order to meet the insertion loss requirement and specified spectral transmission response, we adopt a filter composed of two closely spaced freestanding metal plates, which con- tains an array of resonant ring slot elements. Computer simulation technology （CST） is used to optimize the structural dimensions of the resonant unit and interlayer separation. Numerical results show that these FSS filters exhibit trans- mission loss of less than 0.4 dB and separation between adjacent channels of more than 20 dB. Simulated transmission coefficients are in close agreement with the required specification, and even exceed the performance specifications.展开更多
基金partly supported by the National MCF Energy R&D Program of China(No.2022YFE03060003)partly by the Chinese National Fusion Project for ITER(No.2024YFE03190000)+2 种基金partly by National Natural Science Foundation of China(No.12405254)partly by the Innovation Program of Southwestern Institute of Physics(No.202301XWCX001-02)partly by Sichuan Science and Technology Program(No.2023ZYD0014).
文摘Electron cyclotron emission imaging(ECEI)is a critical diagnostic tool for measuring two-dimensional electron temperature fluctuations.The optical system,a key component of the ECEI diagnostic,determines the spatial resolution,field of view,and imaging performance of electron temperature fluctuations.In this study,comprehensive laboratory tests and characterizations of the optical system,including the local oscillator(LO)coupling optics and the radio frequency(RF)receiving optics,were conducted to ensure optimal performance during plasma discharge experiments.Laboratory testing of the LO optics revealed that the light intensity at the edge channels reaches 36%of that at the central channels;however,both are sufficient to effectively drive the down-converted mixers.The RF optics focus covers the entire non-harmonic overlap region,corresponding to a normalized plasma minor radius range of ρ=−0.2 to 0.9,and offers three zoom modes:narrow,medium,and wide,with poloidal resolutions of 1.5 cm,1.8 cm,and 2.1 cm,respectively.The characterizations for these zoom modes align well with the optical design specifications.It was observed that the imaging surfaces of all zoom modes are exceptionally flat,indicating high-quality ECEI measurements with excellent spatial resolution.The LO lens,focusing lens,and zoom adjustment lens are capable of remote independent control,which enhances the operational flexibility of the system.Preliminary analyses conducted with the ECEI system successfully captured the two-dimensional structure and spatiotemporal evolution of phenomena such as sawtooth crashes,demonstrating the robust capability of the system to provide valuable insights into plasma dynamics.
文摘An improved method for analyzing the radiation characteristic of the quasi-optical launcher is presented. The launcher is decomposed into an open-ended waveguide and a helical cut according to the proposed method. The radiation from the open-ended waveguide is obtained by using the Stratton-Chu formulation. The helical cut＇s radiation is calculated based on its current distribution, gained by several iterative computations, which helps to improve the calculation accuracy since the diffraction effect introduced by the helical cut is considered during the calculation. The proposed method is used to study different launches, and the results are compared with the existing results. Good agreement is achieved between the results obtained from our proposed method and the reported results. The present results provide an alternative for analysis and synthesis of the optical-mode converter.
基金Project supported by the National Natural Science Foundation of China(Grant No.61671032)
文摘We introduce an asymmetrical mirror design to a 140 GHz TE_（22,6） quasi-optical（QO） mode converter system to correct the asymmetry of the beam＇s field distribution caused by the Denisov launcher. By such optimization, the output beam with better symmetrical distribution is obtained at the system＇s output window. Based on the calculated results,the QO mode converter system＇s performance is already satisfying without iterative phase correction. Scalar and vector correlation coefficients between the output beam and the fundamental Gaussian beam are respectively 98.4% and 93.0%,while the total power transmission efficiency of the converter system is 94.4%. The assistance of optical ray tracing to the design of such QO mode converters is introduced and discussed as well.
基金supported by National Natural Science Foundation of China(61102026)Science&Technology Research Project of Chongqing Municipal Educntional Commission of China(KJ120505)
文摘The principle and design method of Denisov-type quasi-optical mode converter is investigated indetail.The operation process of the Denisov-type launcher is analyzed by applying the geometrical optics,andthe Gaussian-like field distribution achieved on the waveguide wall is also derived.The method for designing arippled-wall launcher is proposed on the basis of coupled mode theory.A simulation code for Denisov-type qua-si-optical mode converter GQOMC-D is developed based on coupled mode theory,vector diffraction integrationand physical optics,which is compared to the design parameters and experimental results reported in literaturefor its validity.According to this code,a Denisov-type quasi-optical mode converter used in 110 GHz TE22.6mode gyrotron oscillators is designed.Simulation results indicate that a Gaussian-like beam is obtained at theoutput window with a scalar content of 98.4%and a conversion efficiency of 94.7%.
基金supported by the National Key Research and Development Program of China (Nos. 2017YFE0300200 and 2017YFE0300204)part by National Natural Science Foundation of China (No. 51821005)
文摘The accurate power measurement is important for an ECRH system in tokamak.The dummy load is designed and developed for the measurement of the millimeter wave power.This work analyzes the dummy load based on the quasi-optical method and the ray tracing method.The reflectivity and thermal deposition of the dummy load have been considered to ensure the safety of the entire system.High-power tests have been carried out at a 105 GHz/500 kW ECRH system.The results of the tests indicate that the designed dummy load is stable and valid.
基金Supported by the National Science Foundation of China
文摘The electromagnetic field integral equation in the quasi-optical cavity is obtained using the dyadic Green’s function. An expression is derived for the input impedance of a single microstrip patch cavity excited by a coaxial probe using moment method. The input impedance of a rectangular microstrip patch is discussed with this method. The result of this paper is similar to that of the microstrip antenna. This paper is of very important value for designing microstrip quasi-optical oscillator.
文摘A quasi-optical dielectric lens used for W-band focal plane array passive imaging has been developed. The imaging system requires the lens to form beam spot with 3 dB width less than 35 mm at distance of 3500 mm. The powerful optical design software ZEMAX was utilized to design the contours of the lens, and numerical method based on ray tracing and Huygens’ Principle was processed to verify the design result. Measurement result shows that the 3 dB width of the beam spot formed by the lens is 34 mm at distance of 3460 mm, and the beam pattern on imaging plane are equally arranged and the intensity decreases only 0.55 dB while the object lateral deviation increases to 300 mm.
基金the National Natural Science Foundation of China the Doctoral Fund of Education Committee of China
文摘A novel quasi-opitcal resonance system modified axisymmetrical quasi-optical cavity of oblique ratation(MAQCOR)-is proposed using the laplace integral transormation the kinetic theory of the high relativsitic electron cyclotron maser with MAQCORis carried out within the framowrk of the linearized vlasov-mxawel eauations the formulas of beamwave intreaction power starting current and frequency shift have been derived some important plroblems such as high-order harmonic modes competition inflneces of the rationg angle and space charge and space chrage effcet are andlyaed and discussed in detall and a serios fo new condinsions are obtained a theoretical bssia is laid for the design of this novel qussi-optical gyrotron
文摘This study contributes to renewable energy policy modeling by developing a dynamic decision-making framework that incorporates uncertainty,irreversibility,and the value of information.It responds to the growing need for structured tools to guide investments amid climate volatility,technological change,and economic risk.Grounded in decision theory—especially the work of Von Neumann,Morgenstern,and Savage—the framework models renewable energy investments using subjective probabilities and quasi-option value under evolving climate conditions.The empirical component focuses on ARAMCO’s renewable energy strategy,a corporate case illustrating how fossil-fuel-dependent entities can pivot toward sustainability.The analysis uses Net Present Value(NPV)modeling and real options analysis under different discount rates and carbon pricing scenarios to assess financial feasibility.Results show that lower discount rates and moderate carbon prices improve investment attractiveness,while high carbon pricing significantly reduces project viability.The study also highlights the policy relevance of this framework.Government subsidies,adaptive regulation,and public-private partnerships emerge as critical enablers of resilient investments.It further suggests that aligning ESG reporting standards with carbon pricing policies can strengthen market signals and encourage private capital flow into renewables.By integrating theoretical modeling with corporate investment realities,this chapter offers a replicable tool for policymakers and investors.Future research should expand its application across sectors and geographies to validate generalizability and improve planning in the transition toward low-carbon economies.
文摘We report the design of three frequency selective surface （FSS） filters used on the FengYun-4 （FY-4） microwave satellite, which separate five-frequency bands in the frequency range of 50-429 GHz with the insertion loss less than 0.4 dB, and separation between adjacent channels more than 20 dB for either TE or TM incidence. Firstly, we briefly introduce the disadvantages of two types of FSS filter： waveguide-array FSS and printed FSS, which are commonly employed in the millimeter and sub-millimeter wave band. In order to meet the insertion loss requirement and specified spectral transmission response, we adopt a filter composed of two closely spaced freestanding metal plates, which con- tains an array of resonant ring slot elements. Computer simulation technology （CST） is used to optimize the structural dimensions of the resonant unit and interlayer separation. Numerical results show that these FSS filters exhibit trans- mission loss of less than 0.4 dB and separation between adjacent channels of more than 20 dB. Simulated transmission coefficients are in close agreement with the required specification, and even exceed the performance specifications.
