{"title":"Study of Double-Pulse Magnetic Structure During Decoupling Expansion of Debris Plasma","authors":"Ziming Wang, Ye Dong, Mengmeng Song, Zhaohui Liu, Wei Yang, Qiang Sun, Wenbin Wu, Zhekai Luo, Hantian Zhang, Qianhong Zhou","doi":"10.1029/2024JA033641","DOIUrl":null,"url":null,"abstract":"<p>The decoupling expansion of debris plasma refers to the process where debris plasma generated by a high-altitude nuclear explosion (HANE) slips through the ambient plasma. Unlike the coupled expansion of the debris plasma and ambient plasma, decoupling expansion leads to a smaller magnetic cavity and wider debris dispersal. This significantly alters the magnetic field structures within hundreds of kilometers around the HANE center and even the artificial radiation belt at higher altitude. In this paper, the evolution mechanism of the double-pulse magnetic structure is investigated by simulating the decoupling expansion process of super- Alfvénic debris plasma using a two-dimensional hybrid model. It is found that the rapidly formed azimuthal electron current generates a debris magnetic pulse (the initial magnetic pulse), which remains attached to the expanding debris shell. Subsequently, the spatially nonmonotonically varying ambient ions velocity, characterized by an initial increase followed by a decrease, aggregates ambient ions to gradually form an ambient magnetic pulse (the second magnetic pulse). This study provides essential insights into the magnetic field evolution during the decoupling expansion and the interaction between debris and ambient plasma.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 5","pages":""},"PeriodicalIF":2.9000,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research: Space Physics","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2024JA033641","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
The decoupling expansion of debris plasma refers to the process where debris plasma generated by a high-altitude nuclear explosion (HANE) slips through the ambient plasma. Unlike the coupled expansion of the debris plasma and ambient plasma, decoupling expansion leads to a smaller magnetic cavity and wider debris dispersal. This significantly alters the magnetic field structures within hundreds of kilometers around the HANE center and even the artificial radiation belt at higher altitude. In this paper, the evolution mechanism of the double-pulse magnetic structure is investigated by simulating the decoupling expansion process of super- Alfvénic debris plasma using a two-dimensional hybrid model. It is found that the rapidly formed azimuthal electron current generates a debris magnetic pulse (the initial magnetic pulse), which remains attached to the expanding debris shell. Subsequently, the spatially nonmonotonically varying ambient ions velocity, characterized by an initial increase followed by a decrease, aggregates ambient ions to gradually form an ambient magnetic pulse (the second magnetic pulse). This study provides essential insights into the magnetic field evolution during the decoupling expansion and the interaction between debris and ambient plasma.