Cyclotron Radiation Model of Type III Bursts

III型爆发的回旋辐射模型

• 批准号: 0535821
• 负责人: Ching-Sheng Wu
• 金额: $ 12.5万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-01 至 2008-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0535821&HistoricalAwards=false
• 关键词: Cyclotron; Radiation; Model; Type; III

Solar radio burst phenomena have been traditionally classified into Types I to V. Of these, Type II bursts are associated with interplanetary shock waves (also known as coronal mass ejections or CMEs) while Type III bursts are closely related to flares. Many in the solar radio community feel that Type III bursts are the most well-studied and well-understood solar radio emission phenomenon. In spite of such a pervasive view, there is observational evidence suggesting that the customary theories may not be applicable in some situations. This proposal specifically aims to address some of these difficulties, particularly those associated with Type III bursts.The standard interpretation of radio bursts involves electron beam-generated Langmuir waves that are nonlinearly converted to electromagnetic radiation. While some (or majority) of the observations of coronal and interplanetary Type III bursts can be explained in light of such a scenario (known as the plasma emission model), a shortcoming of this approach is that it ignores the effects of the solar magnetic field. Observational evidence shows that some Type III and other solar radio bursts are closely associated with active regions (sunspots) where the magnetic field is very intense. As an alternative model to the standard theory of Type III bursts, the PI proposes to investigate the effects of these strong magnetic fields on the radiation generation process. In particular, the PI will study the role of the electromagnetic cyclotron maser instability as a source of Type III radio bursts. Over the past few years, the PI and Co-PI have been working very closely with colleagues in China. The proposed project will involve a number of scientists from China, many of whom are junior personnel. The proposed project will obviously encourage international collaboration and promote the education and training of young scientists.

太阳射电爆发现象传统上被分为I型到V型，其中II型爆发与行星际冲击波（也称为日冕物质抛射或CME）有关，而III型爆发与耀斑密切相关。太阳射电界的许多人认为III型爆发是研究得最透彻、理解得最透彻的太阳射电现象。尽管这种观点很普遍，但观察证据表明，习惯理论在某些情况下可能不适用。这个建议特别针对解决这些困难，特别是那些与III型爆发。无线电爆发的标准解释涉及电子束产生的朗缪尔波，非线性转换为电磁辐射。虽然一些（或大多数）日冕和行星际III型爆发的观测可以根据这种情况（称为等离子体发射模型）来解释，但这种方法的缺点是它忽略了太阳磁场的影响。观测证据表明，一些III型和其他太阳射电爆发与磁场非常强烈的活动区域（太阳黑子）密切相关。作为III型爆发标准理论的替代模型，PI建议研究这些强磁场对辐射产生过程的影响。特别是，PI将研究电磁回旋脉泽不稳定性作为III型射电爆发源的作用。在过去的几年里，PI和Co-PI一直与中国的同事密切合作。拟议的项目将涉及一些来自中国的科学家，其中许多是初级人员。拟议的项目显然将鼓励国际合作，促进青年科学家的教育和培训。