On the ambipolar diffusion formulation for ion-neutral drifts in the non-negligible drift velocity limit
dc.contributor.author | Hillier, A | |
dc.date.accessioned | 2024-03-19T10:39:34Z | |
dc.date.issued | 2024-04-25 | |
dc.date.updated | 2024-03-18T23:27:32Z | |
dc.description.abstract | The ambipolar diffusion approximation is used to model partially ionised plasma dynamics in a single fluid setting. To correctly apply the commonly used version of ambipolar diffusion, a set of criteria should be satisfied including the requirement that the difference in velocity between charges and neutral species (known as drift velocity) is much smaller than the thermal velocity, otherwise the drift velocity will drive a non-negligible level of further collisions between the two species. In this paper we explore the consequence of relaxing this assumption. We show that a new induction equation can be formulated without this assumption. This formulation reduces to the ambipolar induction equation in the case the drift velocity is small. In the large drift velocity limit, the feedback of the drift velocity on the collision frequency results in decreased diffusion of the magnetic field compared with the standard ambipolar diffusion approximation for the same parameters. This has a natural consequence of reducing the frictional heating that can occur. Applying this to results from flux emergence simulations where the expansion of the magnetic field leads to strong adiabatic cooling of the partially ionised chromosphere resulted in a noticeable reduction in the magnitude of the predicted drift velocities. | en_GB |
dc.description.sponsorship | Science and Technology Facilities Council (STFC) | en_GB |
dc.identifier.citation | Vol. 382 (2272), article 20230229 | en_GB |
dc.identifier.doi | 10.1098/rsta.2023.0229 | |
dc.identifier.grantnumber | ST/L00397X/2 | en_GB |
dc.identifier.grantnumber | ST/R000891/1 | en_GB |
dc.identifier.grantnumber | ST/V000659/1 | en_GB |
dc.identifier.uri | http://hdl.handle.net/10871/135582 | |
dc.identifier | ORCID: 0000-0002-0851-5362 (Hillier, Andrew) | |
dc.language.iso | en | en_GB |
dc.publisher | The Royal Society | en_GB |
dc.rights | © 2024 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. | en_GB |
dc.title | On the ambipolar diffusion formulation for ion-neutral drifts in the non-negligible drift velocity limit | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2024-03-19T10:39:34Z | |
dc.identifier.issn | 1471-2962 | |
dc.description | This is the final version. Available on open access from the Royal Society via the DOI in this record | en_GB |
dc.identifier.journal | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | en_GB |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | en_GB |
dcterms.dateAccepted | 2024-03-18 | |
dcterms.dateSubmitted | 2023-12-12 | |
rioxxterms.version | VoR | en_GB |
rioxxterms.licenseref.startdate | 2024-03-18 | |
rioxxterms.type | Journal Article/Review | en_GB |
refterms.dateFCD | 2024-03-18T23:27:37Z | |
refterms.versionFCD | AM | |
refterms.dateFOA | 2024-06-25T12:27:28Z | |
refterms.panel | B | en_GB |
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Except where otherwise noted, this item's licence is described as © 2024 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.