WEKO3
アイテム
{"_buckets": {"deposit": "818f6dcc-738c-46f7-a265-271e78718411"}, "_deposit": {"created_by": 1, "id": "48866", "owners": [1], "pid": {"revision_id": 0, "type": "depid", "value": "48866"}, "status": "published"}, "_oai": {"id": "oai:repo.qst.go.jp:00048866", "sets": ["1"]}, "author_link": ["492268", "492267", "492266"], "item_8_biblio_info_7": {"attribute_name": "書誌情報", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2018-05", "bibliographicIssueDateType": "Issued"}, "bibliographicPageEnd": "116063-21", "bibliographicPageStart": "116063-1", "bibliographicVolumeNumber": "57", "bibliographic_titles": [{"bibliographic_title": "Nuclear Fusion"}]}]}, "item_8_description_5": {"attribute_name": "抄録", "attribute_value_mlt": [{"subitem_description": "Using the linear gyrokinetic code LIGKA, we study the structure of the continuous spectra Ω(ρ) = ω(ρ) + iγ(ρ) of shear Alfvén waves (SAW) and ion sound waves (ISW) in a high-beta JT60U tokamak plasma and look for evidence of Alfvén acoustic couplings or mode conversion. Here, Ω is the complex local eigenfrequency, ρ is a radial coordinate, and we consider waves with low toroidal mode number n = 3 . We focus on the frequency range\nω[BAE] \u003c= ω \u003c= ω[TAE] between the beta-induced and toroidicity-induced Alfvén frequency gaps. The real frequencies ω(ρ) of the gyrokinetic ISW continua are remarkably similar to MHD results. The kinetic damping rates are of order −γ/ω ~ 30% for Te /Ti ≈ 1.7 , and reduce to 15% when the temperature ratio is raised to Te /Ti ≈ 4.8 . It is shown that SAW and ISW continua can be simultaneously excited with an antenna and that the global response of the\nISWs is significantly enhanced when the on-axis beta value is raised from β0 = 1.7% to 3.6% while keeping Te /Ti \u003e 1 . In contrast, when the ion temperature is increased such that Te /Ti ≈ 0.4 , ISW branches become undetectable in spite of higher β0 . At the same time, a large part of the SAW continuum is locally destabilized by ion temperature gradients and a set of discrete global modes was found, some of which are weakly damped or unstable and interpreted as kinetic beta-induced Alfvén eigenmodes. It is estimated that the kinetic damping\nof such low-n Alfvénic modes contributes much more to the anomalous bulk ion heating than the excitation of nearby ISW continua, so that Alfvén acoustic couplings in the frequency band ω[BAE] \u003c= ω \u003c= ω[TAE] are irrelevant within the scope of the model used.", "subitem_description_type": "Abstract"}]}, "item_8_relation_14": {"attribute_name": "DOI", "attribute_value_mlt": [{"subitem_relation_type_id": {"subitem_relation_type_id_text": "10.1088/1741-4326/aa80fe", "subitem_relation_type_select": "DOI"}}]}, "item_access_right": {"attribute_name": "アクセス権", "attribute_value_mlt": [{"subitem_access_right": "metadata only access", "subitem_access_right_uri": "http://purl.org/coar/access_right/c_14cb"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "ビアワーゲ, アンドレアス"}], "nameIdentifiers": [{"nameIdentifier": "492266", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Lauber, Philipp"}], "nameIdentifiers": [{"nameIdentifier": "492267", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "ビアワーゲ アンドレアス", "creatorNameLang": "en"}], "nameIdentifiers": [{"nameIdentifier": "492268", "nameIdentifierScheme": "WEKO"}]}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_resource_type": {"attribute_name": "資源タイプ", "attribute_value_mlt": [{"resourcetype": "journal article", "resourceuri": "http://purl.org/coar/resource_type/c_6501"}]}, "item_title": "Gyrokinetic analysis of low-n shear Alfvén and ion sound wave spectra in a high-beta tokamak plasma", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "Gyrokinetic analysis of low-n shear Alfvén and ion sound wave spectra in a high-beta tokamak plasma"}]}, "item_type_id": "8", "owner": "1", "path": ["1"], "permalink_uri": "https://repo.qst.go.jp/records/48866", "pubdate": {"attribute_name": "公開日", "attribute_value": "2018-05-08"}, "publish_date": "2018-05-08", "publish_status": "0", "recid": "48866", "relation": {}, "relation_version_is_last": true, "title": ["Gyrokinetic analysis of low-n shear Alfvén and ion sound wave spectra in a high-beta tokamak plasma"], "weko_shared_id": -1}
Gyrokinetic analysis of low-n shear Alfvén and ion sound wave spectra in a high-beta tokamak plasma
https://repo.qst.go.jp/records/48866
https://repo.qst.go.jp/records/48866e022a7dc-3ea4-4535-8539-aaead10ca7cb
Item type | 学術雑誌論文 / Journal Article(1) | |||||
---|---|---|---|---|---|---|
公開日 | 2018-05-08 | |||||
タイトル | ||||||
タイトル | Gyrokinetic analysis of low-n shear Alfvén and ion sound wave spectra in a high-beta tokamak plasma | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
資源タイプ | journal article | |||||
アクセス権 | ||||||
アクセス権 | metadata only access | |||||
アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
著者 |
ビアワーゲ, アンドレアス
× ビアワーゲ, アンドレアス× Lauber, Philipp× ビアワーゲ アンドレアス |
|||||
抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | Using the linear gyrokinetic code LIGKA, we study the structure of the continuous spectra Ω(ρ) = ω(ρ) + iγ(ρ) of shear Alfvén waves (SAW) and ion sound waves (ISW) in a high-beta JT60U tokamak plasma and look for evidence of Alfvén acoustic couplings or mode conversion. Here, Ω is the complex local eigenfrequency, ρ is a radial coordinate, and we consider waves with low toroidal mode number n = 3 . We focus on the frequency range ω[BAE] <= ω <= ω[TAE] between the beta-induced and toroidicity-induced Alfvén frequency gaps. The real frequencies ω(ρ) of the gyrokinetic ISW continua are remarkably similar to MHD results. The kinetic damping rates are of order −γ/ω ~ 30% for Te /Ti ≈ 1.7 , and reduce to 15% when the temperature ratio is raised to Te /Ti ≈ 4.8 . It is shown that SAW and ISW continua can be simultaneously excited with an antenna and that the global response of the ISWs is significantly enhanced when the on-axis beta value is raised from β0 = 1.7% to 3.6% while keeping Te /Ti > 1 . In contrast, when the ion temperature is increased such that Te /Ti ≈ 0.4 , ISW branches become undetectable in spite of higher β0 . At the same time, a large part of the SAW continuum is locally destabilized by ion temperature gradients and a set of discrete global modes was found, some of which are weakly damped or unstable and interpreted as kinetic beta-induced Alfvén eigenmodes. It is estimated that the kinetic damping of such low-n Alfvénic modes contributes much more to the anomalous bulk ion heating than the excitation of nearby ISW continua, so that Alfvén acoustic couplings in the frequency band ω[BAE] <= ω <= ω[TAE] are irrelevant within the scope of the model used. |
|||||
書誌情報 |
Nuclear Fusion 巻 57, p. 116063-1-116063-21, 発行日 2018-05 |
|||||
DOI | ||||||
識別子タイプ | DOI | |||||
関連識別子 | 10.1088/1741-4326/aa80fe |