{"title":"ECR等离子体微波耦合的简化模型","authors":"M. Cavenago","doi":"10.23919/URSIGASS51995.2021.9560454","DOIUrl":null,"url":null,"abstract":"A magnetized plasma strongly interacts with microwaves, when their angular frequency <tex>$\\omega$</tex> is around the electron cyclotron resonance (ECR) one, that is <tex>$\\Omega=e\\vert \\mathrm{B}^{s}\\vert /m_{e}$</tex>, with <tex>$\\mathrm{B}^{s}$</tex> the static flux density. The case of small ion sources with <tex>$\\mathrm{B}^{s}\\cong 0.5$</tex> to 1 T, where wavelength and plasma chamber radius are comparable, is studied with full wave equations, assuming a collision rate <tex>$v$</tex> and a plasma of given density. Wave initially launched in the TE mode from a waveguide (TE<inf>11</inf> for a circular waveguide), aligned with the axis <tex>$z$</tex> of a cylindrical plasma chamber and of <tex>$\\mathrm{B}^{s}$</tex>, are partially converted to <tex>$E_{z}$</tex> waves; use of azimuthal symmetry to consider only the <tex>$m=1$</tex> component is discussed. Large reflections are sometimes observed as a function of ratio of plasma angular frequency <tex>$\\omega_{p}(z)$</tex> and <tex>$\\omega$</tex>, possibly due to model simplification (density constant in <tex>$x$</tex> and <tex>$y$</tex>). Extension to off-axis waveguides (perhaps rectangular or coaxial) is mentioned.","PeriodicalId":152047,"journal":{"name":"2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2021-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"A Simplified Model of Microwave Coupling in ECR Plasmas\",\"authors\":\"M. Cavenago\",\"doi\":\"10.23919/URSIGASS51995.2021.9560454\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"A magnetized plasma strongly interacts with microwaves, when their angular frequency <tex>$\\\\omega$</tex> is around the electron cyclotron resonance (ECR) one, that is <tex>$\\\\Omega=e\\\\vert \\\\mathrm{B}^{s}\\\\vert /m_{e}$</tex>, with <tex>$\\\\mathrm{B}^{s}$</tex> the static flux density. The case of small ion sources with <tex>$\\\\mathrm{B}^{s}\\\\cong 0.5$</tex> to 1 T, where wavelength and plasma chamber radius are comparable, is studied with full wave equations, assuming a collision rate <tex>$v$</tex> and a plasma of given density. Wave initially launched in the TE mode from a waveguide (TE<inf>11</inf> for a circular waveguide), aligned with the axis <tex>$z$</tex> of a cylindrical plasma chamber and of <tex>$\\\\mathrm{B}^{s}$</tex>, are partially converted to <tex>$E_{z}$</tex> waves; use of azimuthal symmetry to consider only the <tex>$m=1$</tex> component is discussed. Large reflections are sometimes observed as a function of ratio of plasma angular frequency <tex>$\\\\omega_{p}(z)$</tex> and <tex>$\\\\omega$</tex>, possibly due to model simplification (density constant in <tex>$x$</tex> and <tex>$y$</tex>). Extension to off-axis waveguides (perhaps rectangular or coaxial) is mentioned.\",\"PeriodicalId\":152047,\"journal\":{\"name\":\"2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)\",\"volume\":\"19 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-08-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.23919/URSIGASS51995.2021.9560454\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"2021 XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.23919/URSIGASS51995.2021.9560454","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
A Simplified Model of Microwave Coupling in ECR Plasmas
A magnetized plasma strongly interacts with microwaves, when their angular frequency $\omega$ is around the electron cyclotron resonance (ECR) one, that is $\Omega=e\vert \mathrm{B}^{s}\vert /m_{e}$, with $\mathrm{B}^{s}$ the static flux density. The case of small ion sources with $\mathrm{B}^{s}\cong 0.5$ to 1 T, where wavelength and plasma chamber radius are comparable, is studied with full wave equations, assuming a collision rate $v$ and a plasma of given density. Wave initially launched in the TE mode from a waveguide (TE11 for a circular waveguide), aligned with the axis $z$ of a cylindrical plasma chamber and of $\mathrm{B}^{s}$, are partially converted to $E_{z}$ waves; use of azimuthal symmetry to consider only the $m=1$ component is discussed. Large reflections are sometimes observed as a function of ratio of plasma angular frequency $\omega_{p}(z)$ and $\omega$, possibly due to model simplification (density constant in $x$ and $y$). Extension to off-axis waveguides (perhaps rectangular or coaxial) is mentioned.