Pub Date : 2025-01-24DOI: 10.1109/TPS.2025.3527476
Kirk J. Boehm;James D. Rogers;Richard D. Branam
Langmuir probe measurements have been performed many times in hollow cathodes and remain one of the most commonly used diagnostic methods to determine electron temperature, density, and plasma potential. The objective of this project was to analyze which possible electron processes can also be determined using a single-wire Langmuir probe in combination with the Druyvesteyn electron energy distribution function (EEDF) method. The well-documented JPL NASA LaB6 hollow cathode using argon, without a heater and without an orifice, was chosen for this study. The probe tip was located at the backend of the plasma. The Druyvesteyn EEDF method resulted in three distinct electron population peaks, representing single ionization, secondary electron production due to ion bombardment of the low work function insert, and thermionic electron production. The electron temperature for almost all three peaks decreased slightly with increasing mass flow rate. The electron number density also decreased with mass flow rate; however, each population showed a different rate of decrease. The detection showed different populations for different locations in the upstream plasma sheath. The results of this investigation indicate that thermionic emission, secondary ion bombardment, ionization, and their associated electron extractions can be measured using the Druyvesteyn EEDF method.
{"title":"Analysis of the Electron Distribution Function Inside of a LaB₆ Hollow Cathode","authors":"Kirk J. Boehm;James D. Rogers;Richard D. Branam","doi":"10.1109/TPS.2025.3527476","DOIUrl":"https://doi.org/10.1109/TPS.2025.3527476","url":null,"abstract":"Langmuir probe measurements have been performed many times in hollow cathodes and remain one of the most commonly used diagnostic methods to determine electron temperature, density, and plasma potential. The objective of this project was to analyze which possible electron processes can also be determined using a single-wire Langmuir probe in combination with the Druyvesteyn electron energy distribution function (EEDF) method. The well-documented JPL NASA LaB6 hollow cathode using argon, without a heater and without an orifice, was chosen for this study. The probe tip was located at the backend of the plasma. The Druyvesteyn EEDF method resulted in three distinct electron population peaks, representing single ionization, secondary electron production due to ion bombardment of the low work function insert, and thermionic electron production. The electron temperature for almost all three peaks decreased slightly with increasing mass flow rate. The electron number density also decreased with mass flow rate; however, each population showed a different rate of decrease. The detection showed different populations for different locations in the upstream plasma sheath. The results of this investigation indicate that thermionic emission, secondary ion bombardment, ionization, and their associated electron extractions can be measured using the Druyvesteyn EEDF method.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"63-70"},"PeriodicalIF":1.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1109/TPS.2025.3527373
Kamal M. Ahmed;A. H. Bekheit;M. M. Abdelrahman
In magnetic confinement reactors, the radial electric field and its shear are very important for edge transport barrier (ETB) formation and turbulence suppression. In the present work, a multifluid transport code, B2SOLPS5.02D, was used to model the radial distribution of plasma parameters (such as electron density, electron temperature, and ion velocity), radial electric field, and its shear in both cases with and without the ETB formation in small size divertor tokamak (SSDT) devices. The results demonstrated that the radial electric field in the ETB mode is similar to the neoclassical electric field near the separatrix. A toroidal rotation was observed in the co-current/counter-current directions in the discharge without/with the ETB, respectively. An intense radial electric field shear developed, resulting in a significant reduction in the transport coefficient. The ETB region appeared to be located between the maximum and minimum values of the radial electric field shear. Furthermore, the results demonstrated that the ETB width was proportional to the ion temperature and inversely proportional to the radial electric field shear. The impact of the radial electric field shear on the diffusion coefficient, plasma density, and ETB formation was investigated.
{"title":"Comparative Analysis of Radial Plasma Parameters and Electric Field Shear With and Without the Edge Transport Barrier Formation in SSDT Devices","authors":"Kamal M. Ahmed;A. H. Bekheit;M. M. Abdelrahman","doi":"10.1109/TPS.2025.3527373","DOIUrl":"https://doi.org/10.1109/TPS.2025.3527373","url":null,"abstract":"In magnetic confinement reactors, the radial electric field and its shear are very important for edge transport barrier (ETB) formation and turbulence suppression. In the present work, a multifluid transport code, B2SOLPS5.02D, was used to model the radial distribution of plasma parameters (such as electron density, electron temperature, and ion velocity), radial electric field, and its shear in both cases with and without the ETB formation in small size divertor tokamak (SSDT) devices. The results demonstrated that the radial electric field in the ETB mode is similar to the neoclassical electric field near the separatrix. A toroidal rotation was observed in the co-current/counter-current directions in the discharge without/with the ETB, respectively. An intense radial electric field shear developed, resulting in a significant reduction in the transport coefficient. The ETB region appeared to be located between the maximum and minimum values of the radial electric field shear. Furthermore, the results demonstrated that the ETB width was proportional to the ion temperature and inversely proportional to the radial electric field shear. The impact of the radial electric field shear on the diffusion coefficient, plasma density, and ETB formation was investigated.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"122-135"},"PeriodicalIF":1.3,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-17DOI: 10.1109/TPS.2024.3522894
Pallabi Pathak;H. Bailung
Evolution of large-amplitude ion-acoustic shock in plasma containing electrons, $text {Ar}^{+}$ and $text {F}^{-}$ ions, has been investigated. As for the extremely high-amplitude shock wave in multicomponent plasma with negative ions, we achieved a density perturbation of ~70%, in contrast to the ~15% density perturbation observed in an electron-ion plasma. The numerical results of well-known Korteweg-de Vries (KdV)–Burger equation were employed in order to compare our exquisite observations. Furthermore, we explore the impact of enhanced Landau damping on the large-amplitude shocks in the plasma containing negative ions. The negative-to-positive ion density ratio is kept at approximately $r(=n_{-}{/}{n}_{+})sim 0.25$ .
{"title":"Investigation on Large-Amplitude Ion-Acoustic Shock in Negative Ion Plasma","authors":"Pallabi Pathak;H. Bailung","doi":"10.1109/TPS.2024.3522894","DOIUrl":"https://doi.org/10.1109/TPS.2024.3522894","url":null,"abstract":"Evolution of large-amplitude ion-acoustic shock in plasma containing electrons, <inline-formula> <tex-math>$text {Ar}^{+}$ </tex-math></inline-formula> and <inline-formula> <tex-math>$text {F}^{-}$ </tex-math></inline-formula> ions, has been investigated. As for the extremely high-amplitude shock wave in multicomponent plasma with negative ions, we achieved a density perturbation of ~70%, in contrast to the ~15% density perturbation observed in an electron-ion plasma. The numerical results of well-known Korteweg-de Vries (KdV)–Burger equation were employed in order to compare our exquisite observations. Furthermore, we explore the impact of enhanced Landau damping on the large-amplitude shocks in the plasma containing negative ions. The negative-to-positive ion density ratio is kept at approximately <inline-formula> <tex-math>$r(=n_{-}{/}{n}_{+})sim 0.25$ </tex-math></inline-formula>.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"3-11"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To suppress the backward wave oscillations in traveling wave tube (TWT) amplifiers, which are caused by the high gain of higher-order modes, mode selective folded waveguide (MSFW) is proposed as a slow wave structure (SWS). The MSFW consists of folded waveguide (FW) and mode selective circuit (MSC). Specifically, the MSC is made up of two segments of discontinuous rectangular waveguides. Consequently, the MSC can realize the suppression of the higher-order modes of the FW effectively and thus improve the performance of the FW-TWT. The simulation results show that the single-segment MSFW-TWT has a 3-dB bandwidth of 212.5–218.5 GHz, a saturated output power of more than 72 W, and a maximal gain of 39.59 dB. Meanwhile, the risk of the TWT’s backward wave oscillations is greatly reduced. As a result, the great potential of MSFW as a terahertz (THz) amplifier can be clearly seen from these results.
{"title":"A G-Band Traveling Wave Tube Based on Mode Selection Circuit for Suppressing Backward Wave Oscillation","authors":"Zechuan Wang;Zhigang Lu;Peng Gao;Li Qiu;Jingrui Duan;Zhanliang Wang;Shaomeng Wang;Yuan Zheng;Huarong Gong;Yubin Gong","doi":"10.1109/TPS.2024.3524420","DOIUrl":"https://doi.org/10.1109/TPS.2024.3524420","url":null,"abstract":"To suppress the backward wave oscillations in traveling wave tube (TWT) amplifiers, which are caused by the high gain of higher-order modes, mode selective folded waveguide (MSFW) is proposed as a slow wave structure (SWS). The MSFW consists of folded waveguide (FW) and mode selective circuit (MSC). Specifically, the MSC is made up of two segments of discontinuous rectangular waveguides. Consequently, the MSC can realize the suppression of the higher-order modes of the FW effectively and thus improve the performance of the FW-TWT. The simulation results show that the single-segment MSFW-TWT has a 3-dB bandwidth of 212.5–218.5 GHz, a saturated output power of more than 72 W, and a maximal gain of 39.59 dB. Meanwhile, the risk of the TWT’s backward wave oscillations is greatly reduced. As a result, the great potential of MSFW as a terahertz (THz) amplifier can be clearly seen from these results.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"146-152"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-17DOI: 10.1109/TPS.2024.3522911
Yun-Sik Jin;Chuhyun Cho;Chae-Hwa Shon;Daejong Kim;Keekon Kang;Sung-Roc Jang
In the agricultural and food industries, there is an urgent need for large-capacity and high-efficiency plasma-activated water (PAW) production technology. Regarding this matter, we demonstrate the mass production of PAW with high efficiency based on reverse vortex flow (RVF) gliding arc (GA) plasma with an input power of 4 kW or higher. With the current system, the production capacity of the PAW with pH 3.0 is 1000 L/h for distilled water and 500 L/h for tap water. The amount of ${mathrm {NO}}_{3}^{-}$ ion in the PAW was 60 g/kWh, which is ten times higher than that of a dielectric barrier discharge (DBD) method. The produced PAW tends to show a higher acidity for a longer storage time.
{"title":"High-Efficiency Mass Production of Plasma Activated Water by the Gliding Arc Plasma","authors":"Yun-Sik Jin;Chuhyun Cho;Chae-Hwa Shon;Daejong Kim;Keekon Kang;Sung-Roc Jang","doi":"10.1109/TPS.2024.3522911","DOIUrl":"https://doi.org/10.1109/TPS.2024.3522911","url":null,"abstract":"In the agricultural and food industries, there is an urgent need for large-capacity and high-efficiency plasma-activated water (PAW) production technology. Regarding this matter, we demonstrate the mass production of PAW with high efficiency based on reverse vortex flow (RVF) gliding arc (GA) plasma with an input power of 4 kW or higher. With the current system, the production capacity of the PAW with pH 3.0 is 1000 L/h for distilled water and 500 L/h for tap water. The amount of <inline-formula> <tex-math>${mathrm {NO}}_{3}^{-}$ </tex-math></inline-formula> ion in the PAW was 60 g/kWh, which is ten times higher than that of a dielectric barrier discharge (DBD) method. The produced PAW tends to show a higher acidity for a longer storage time.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"34-39"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we present a contribution on the applicability of the recursive least squares method used for the parametric identification of a corona discharge phenomenon at small distances. Furthermore, we show the influence of the choice of the forgetting factor for a better performance of the identification operation and the quality of estimation of the identified parameters. The identification process is based on experimental input/output measurements. The validation of the parameter results is done by a physical analysis of the behaviors of these parameters and by comparing the output calculated according to these parameters, with the real output obtained experimentally. The results show that with a constant forgetting factor close to 1 ($lambda = 0.99$ ), parameter quality improves but output accuracy may vary. In contrast, a variable forgetting factor enhances both parameter quality and model output consistently. A good agreement observed between the real and calculated outputs confirms both the good choice of the forgetting factor and the precision of the estimated parameters as well as the validity of the identified model in general.
{"title":"Influence of the Forgetting Factor in the Recursive Least Squares RLS Algorithm on the Quality and Precision of the Identified Parameters in a DC Corona Discharge","authors":"Tahtah Abdelkarim;Raouti Driss;Olivier Eichwald;Lionel Vido;Nassour Kamel;Bouanane Abdelkrim","doi":"10.1109/TPS.2024.3524470","DOIUrl":"https://doi.org/10.1109/TPS.2024.3524470","url":null,"abstract":"In this work, we present a contribution on the applicability of the recursive least squares method used for the parametric identification of a corona discharge phenomenon at small distances. Furthermore, we show the influence of the choice of the forgetting factor for a better performance of the identification operation and the quality of estimation of the identified parameters. The identification process is based on experimental input/output measurements. The validation of the parameter results is done by a physical analysis of the behaviors of these parameters and by comparing the output calculated according to these parameters, with the real output obtained experimentally. The results show that with a constant forgetting factor close to 1 (<inline-formula> <tex-math>$lambda = 0.99$ </tex-math></inline-formula>), parameter quality improves but output accuracy may vary. In contrast, a variable forgetting factor enhances both parameter quality and model output consistently. A good agreement observed between the real and calculated outputs confirms both the good choice of the forgetting factor and the precision of the estimated parameters as well as the validity of the identified model in general.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"108-115"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The immense waste generated from sweet orange (Citrus sinensis) peel during processing poses significant challenges in waste management, contributing to environmental pollution and health hazards. This study explores the impact of plasma-activated water (PAW) on sweet orange peel, focusing on polyphenols total phenol content (TPC), total flavonoid content (TFC), total terpenoid content (TTC), flavonoids (hesperidin, naringin), limonin, antioxidant activity 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and anti-nutritional factors (tannin, phytic acid, and saponin), with an emphasis on optimization. The central composite rotatable design (CCRD) was employed, resulting in 13 experimental runs with independent parameters set at 7–13 kV (voltage) and 60–180 min (soaking time). PAW treatment significantly enhanced total polyphenols [112.52- ± 4.63- to 170.56- ± 5.78-mg gallic acid equivalent (GAE)/100 g], total flavonoids (621.26- ±25.15- to 972.69- ±80.29-mg QE/100 g), and antioxidant activities (DPPH 37.59% ±3.71% to 79.61% ±1.83% and FRAP 96.34- ±2.13- to 256.01- ±11.8-$mu $ g AA/g) in sweet orange peel powder (SOPP). Conversely, TTC, naringin, limonin, and anti-nutrients decreased compared to control samples. Fourier transform infrared (FT-IR) analysis revealed characteristic peaks, confirming the alteration of polyphenolic functional groups. This study presents strategies for valorizing SOPP, enhancing its polyphenols and antioxidant properties for potential applications in nutraceuticals and novel functional foods.
{"title":"Enhancing Nutritional Potential: Plasma-Activated Water Treatment on Sweet Orange Peel Powder—Polyphenols, Flavonoids, Antioxidants, and Anti-Nutrients Optimization","authors":"Venkatraman Bansode;Tarak Chandra Panda;Samuel Jaddu;Sibasish Sahoo;Kadavakollu Subrahmanyam;V. Vignesh;Thota Niranjan;Rama Chandra Pradhan;Madhuresh Dwivedi","doi":"10.1109/TPS.2024.3523670","DOIUrl":"https://doi.org/10.1109/TPS.2024.3523670","url":null,"abstract":"The immense waste generated from sweet orange (Citrus sinensis) peel during processing poses significant challenges in waste management, contributing to environmental pollution and health hazards. This study explores the impact of plasma-activated water (PAW) on sweet orange peel, focusing on polyphenols total phenol content (TPC), total flavonoid content (TFC), total terpenoid content (TTC), flavonoids (hesperidin, naringin), limonin, antioxidant activity 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and anti-nutritional factors (tannin, phytic acid, and saponin), with an emphasis on optimization. The central composite rotatable design (CCRD) was employed, resulting in 13 experimental runs with independent parameters set at 7–13 kV (voltage) and 60–180 min (soaking time). PAW treatment significantly enhanced total polyphenols [112.52- ± 4.63- to 170.56- ± 5.78-mg gallic acid equivalent (GAE)/100 g], total flavonoids (621.26- ±25.15- to 972.69- ±80.29-mg QE/100 g), and antioxidant activities (DPPH 37.59% ±3.71% to 79.61% ±1.83% and FRAP 96.34- ±2.13- to 256.01- ±11.8-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>g AA/g) in sweet orange peel powder (SOPP). Conversely, TTC, naringin, limonin, and anti-nutrients decreased compared to control samples. Fourier transform infrared (FT-IR) analysis revealed characteristic peaks, confirming the alteration of polyphenolic functional groups. This study presents strategies for valorizing SOPP, enhancing its polyphenols and antioxidant properties for potential applications in nutraceuticals and novel functional foods.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"51-62"},"PeriodicalIF":1.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article, a 1-THz fourth harmonic complex cavity gyrotron with the magnetic cusp gun (MCG) has been investigated theoretically with the self-consistent nonlinear theory. The self-consistent nonlinear theory is composed of the electron motion equation and the electron excitation equation, which could accurately describe the interaction process between the electron beam and electromagnetic wave. The MCG is optimized to generate a large-orbit beam (LOB), and the complex cavity is designed to suppress parasitic modes and improve the output efficiency. The complex cavity gyrotron is optimized to operate at a frequency of 1-THz, achieving an output efficiency of 1% and an output power of 0.5 kW when the beam voltage is 59 kV, the beam current is 0.8 A, and the magnetic field is 9.9 T. The effects of the beam voltage, the beam current, and the pitch factor of the electron beam on the output efficiency are analyzed. Results show that when the beam voltage varies between 57 and 61 kV, the beam current between 0.3 and 1.2 A, and the pitch factor between 1.05 and 1.5, the output efficiency of the gyrotron is maintained above 0.7%. The effects of the beam quality, including the velocity spread and the beam thickness on the output efficiency, are discussed as well. Meanwhile, the effects of machining errors including structure changes of the complex cavity gyrotron and the eccentricity angle of the cathode in MCG on the output efficiency are discussed.
{"title":"Simulation of a 1-THz Complex Cavity Gyrotron With a Magnetic Cusp Gun","authors":"Xu Qi;Zhi Yi;Tao Song;Yuxuan Chai;Taotao Mao;Chen Zhang;Peisheng Liang;Chenghui Zhu;Jiao Jiao;Na Yao;Kaichun Zhang;Zhenhua Wu;Yanyu Wei;Yubin Gong;Wei Wang;Diwei Liu","doi":"10.1109/TPS.2025.3526243","DOIUrl":"https://doi.org/10.1109/TPS.2025.3526243","url":null,"abstract":"In this article, a 1-THz fourth harmonic complex cavity gyrotron with the magnetic cusp gun (MCG) has been investigated theoretically with the self-consistent nonlinear theory. The self-consistent nonlinear theory is composed of the electron motion equation and the electron excitation equation, which could accurately describe the interaction process between the electron beam and electromagnetic wave. The MCG is optimized to generate a large-orbit beam (LOB), and the complex cavity is designed to suppress parasitic modes and improve the output efficiency. The complex cavity gyrotron is optimized to operate at a frequency of 1-THz, achieving an output efficiency of 1% and an output power of 0.5 kW when the beam voltage is 59 kV, the beam current is 0.8 A, and the magnetic field is 9.9 T. The effects of the beam voltage, the beam current, and the pitch factor of the electron beam on the output efficiency are analyzed. Results show that when the beam voltage varies between 57 and 61 kV, the beam current between 0.3 and 1.2 A, and the pitch factor between 1.05 and 1.5, the output efficiency of the gyrotron is maintained above 0.7%. The effects of the beam quality, including the velocity spread and the beam thickness on the output efficiency, are discussed as well. Meanwhile, the effects of machining errors including structure changes of the complex cavity gyrotron and the eccentricity angle of the cathode in MCG on the output efficiency are discussed.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"153-160"},"PeriodicalIF":1.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-14DOI: 10.1109/TPS.2024.3520713
Daisheng Zhang;Wenxuan Liao;Xiaojun Sun;Wei Chen;Lixia Yang
In this study, the Bhatnagar-Gross–Krook (BGK) collision model for weakly ionized dusty plasmas is obtained and the FDTD iterative equations for dusty plasma in the time-varying case is derived in combination with the Z-finite difference time domain (Z-FDTD) method (2-D TM wave). The electromagnetic (EM) scattering characteristic of a time-varying hypersonic target with a dusty plasma coating in the BGK collision model is studied by calculating the radar scattering cross section (RCS) with varying dust particle radius, dust particle concentration ratio, dusty plasma relaxation time, collision frequency, incident angle, and time-varying laws of electron density in the dusty plasma. Results show that the increase in dust particle radius and concentration, as influenced by the charging effect of dust particles, enhances the scattering of EM waves. This improvement leads to the increment in RCS. The augmented charging and collision frequencies of dusty plasma intensify the collision effect of electrons, ions, and dust particles, which decreases RCS. In addition, the effects of different incident angles and time-varying laws on the RCS are analyzed. In addition, the change in incident angle causes deviations in the overall change in RCS. Furthermore, different time-varying laws change the oscillation amplitude of RCS to some extent. These results provide theoretical support for solving the “communication blackout” problem.
{"title":"Study on the Electromagnetic Scattering Characteristics of Time-Varying Dusty Plasma Target in the BGK Collision Model-TM Case","authors":"Daisheng Zhang;Wenxuan Liao;Xiaojun Sun;Wei Chen;Lixia Yang","doi":"10.1109/TPS.2024.3520713","DOIUrl":"https://doi.org/10.1109/TPS.2024.3520713","url":null,"abstract":"In this study, the Bhatnagar-Gross–Krook (BGK) collision model for weakly ionized dusty plasmas is obtained and the FDTD iterative equations for dusty plasma in the time-varying case is derived in combination with the Z-finite difference time domain (Z-FDTD) method (2-D TM wave). The electromagnetic (EM) scattering characteristic of a time-varying hypersonic target with a dusty plasma coating in the BGK collision model is studied by calculating the radar scattering cross section (RCS) with varying dust particle radius, dust particle concentration ratio, dusty plasma relaxation time, collision frequency, incident angle, and time-varying laws of electron density in the dusty plasma. Results show that the increase in dust particle radius and concentration, as influenced by the charging effect of dust particles, enhances the scattering of EM waves. This improvement leads to the increment in RCS. The augmented charging and collision frequencies of dusty plasma intensify the collision effect of electrons, ions, and dust particles, which decreases RCS. In addition, the effects of different incident angles and time-varying laws on the RCS are analyzed. In addition, the change in incident angle causes deviations in the overall change in RCS. Furthermore, different time-varying laws change the oscillation amplitude of RCS to some extent. These results provide theoretical support for solving the “communication blackout” problem.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"53 1","pages":"116-121"},"PeriodicalIF":1.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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