{"title":"在存在 \"空心 \"非麦克斯韦电子分布的情况下减少快速离子阻力","authors":"A P L Robinson","doi":"10.1088/1361-6587/ad238f","DOIUrl":null,"url":null,"abstract":"It is argued that the electronic stopping power in a plasma should be expected to exhibit significant differences in the presence of effects that shift the electron distribution function away from a Maxwellian. This is potentially important for nuclear reactions produced by laser-driven ion beams, where non-Maxwellian effects may have to be considered. We have calculated the electronic stopping power for a number of model distributions. Importantly, comparisons with the Maxwellian are done under the condition of energy density parity. ‘Hollow’ electron distribution functions (e.g. <inline-formula>\n<tex-math><?CDATA $f \\propto v^nf_{\\text{max}}$?></tex-math>\n<mml:math overflow=\"scroll\"><mml:mi>f</mml:mi><mml:mo>∝</mml:mo><mml:msup><mml:mi>v</mml:mi><mml:mi>n</mml:mi></mml:msup><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mtext>max</mml:mtext></mml:mrow></mml:msub></mml:math>\n<inline-graphic xlink:href=\"ppcfad238fieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\n</inline-formula>) could be expected to show a reduced stopping power (when <inline-formula>\n<tex-math><?CDATA $v_\\mathrm{i}/v_\\mathrm{t} \\lt 1$?></tex-math>\n<mml:math overflow=\"scroll\"><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">i</mml:mi></mml:mrow></mml:msub><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">t</mml:mi></mml:mrow></mml:msub><mml:mo><</mml:mo><mml:mn>1</mml:mn></mml:math>\n<inline-graphic xlink:href=\"ppcfad238fieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\n</inline-formula>). We show that this is indeed the case and that the difference can become a factor of 70. The super-Gaussian electron distribution function, on the other hand, will always show a higher stopping power than the Maxwellian for orders greater than 2.","PeriodicalId":20239,"journal":{"name":"Plasma Physics and Controlled Fusion","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Reduction of fast ion drag in the presence of ‘hollow’ non-Maxwellian electron distributions\",\"authors\":\"A P L Robinson\",\"doi\":\"10.1088/1361-6587/ad238f\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"It is argued that the electronic stopping power in a plasma should be expected to exhibit significant differences in the presence of effects that shift the electron distribution function away from a Maxwellian. This is potentially important for nuclear reactions produced by laser-driven ion beams, where non-Maxwellian effects may have to be considered. We have calculated the electronic stopping power for a number of model distributions. Importantly, comparisons with the Maxwellian are done under the condition of energy density parity. ‘Hollow’ electron distribution functions (e.g. <inline-formula>\\n<tex-math><?CDATA $f \\\\propto v^nf_{\\\\text{max}}$?></tex-math>\\n<mml:math overflow=\\\"scroll\\\"><mml:mi>f</mml:mi><mml:mo>∝</mml:mo><mml:msup><mml:mi>v</mml:mi><mml:mi>n</mml:mi></mml:msup><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mtext>max</mml:mtext></mml:mrow></mml:msub></mml:math>\\n<inline-graphic xlink:href=\\\"ppcfad238fieqn1.gif\\\" xlink:type=\\\"simple\\\"></inline-graphic>\\n</inline-formula>) could be expected to show a reduced stopping power (when <inline-formula>\\n<tex-math><?CDATA $v_\\\\mathrm{i}/v_\\\\mathrm{t} \\\\lt 1$?></tex-math>\\n<mml:math overflow=\\\"scroll\\\"><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi mathvariant=\\\"normal\\\">i</mml:mi></mml:mrow></mml:msub><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi mathvariant=\\\"normal\\\">t</mml:mi></mml:mrow></mml:msub><mml:mo><</mml:mo><mml:mn>1</mml:mn></mml:math>\\n<inline-graphic xlink:href=\\\"ppcfad238fieqn2.gif\\\" xlink:type=\\\"simple\\\"></inline-graphic>\\n</inline-formula>). We show that this is indeed the case and that the difference can become a factor of 70. The super-Gaussian electron distribution function, on the other hand, will always show a higher stopping power than the Maxwellian for orders greater than 2.\",\"PeriodicalId\":20239,\"journal\":{\"name\":\"Plasma Physics and Controlled Fusion\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.1000,\"publicationDate\":\"2024-02-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Plasma Physics and Controlled Fusion\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1088/1361-6587/ad238f\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, FLUIDS & PLASMAS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plasma Physics and Controlled Fusion","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1361-6587/ad238f","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, FLUIDS & PLASMAS","Score":null,"Total":0}
Reduction of fast ion drag in the presence of ‘hollow’ non-Maxwellian electron distributions
It is argued that the electronic stopping power in a plasma should be expected to exhibit significant differences in the presence of effects that shift the electron distribution function away from a Maxwellian. This is potentially important for nuclear reactions produced by laser-driven ion beams, where non-Maxwellian effects may have to be considered. We have calculated the electronic stopping power for a number of model distributions. Importantly, comparisons with the Maxwellian are done under the condition of energy density parity. ‘Hollow’ electron distribution functions (e.g. f∝vnfmax) could be expected to show a reduced stopping power (when vi/vt<1). We show that this is indeed the case and that the difference can become a factor of 70. The super-Gaussian electron distribution function, on the other hand, will always show a higher stopping power than the Maxwellian for orders greater than 2.
期刊介绍:
Plasma Physics and Controlled Fusion covers all aspects of the physics of hot, highly ionised plasmas. This includes results of current experimental and theoretical research on all aspects of the physics of high-temperature plasmas and of controlled nuclear fusion, including the basic phenomena in highly-ionised gases in the laboratory, in the ionosphere and in space, in magnetic-confinement and inertial-confinement fusion as well as related diagnostic methods.
Papers with a technological emphasis, for example in such topics as plasma control, fusion technology and diagnostics, are welcomed when the plasma physics is an integral part of the paper or when the technology is unique to plasma applications or new to the field of plasma physics. Papers on dusty plasma physics are welcome when there is a clear relevance to fusion.