Blob interactions in 2D scrape-off layer simulations
| Autor: | Decristoforo, G., Militello, F., Nicholas, T., Omotani, J., Marsden, C., Walkden, N., Garcia, O. E. |
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| Rok vydání: | 2020 |
| Předmět: |
Astrophysics::High Energy Astrophysical Phenomena
Population FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Tracking (particle physics) 01 natural sciences 010305 fluids & plasmas law.invention law Position (vector) Physics::Plasma Physics Intermittency 0103 physical sciences 010306 general physics education Scaling Physics education.field_of_study VDP::Mathematics and natural science: 400::Physics: 430::Space and plasma physics: 437 Plasma Condensed Matter Physics Physics - Plasma Physics Computational physics Plasma Physics (physics.plasm-ph) Amplitude VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430::Rom- og plasmafysikk: 437 Center of mass |
| Zdroj: | Physics of Plasmas |
| ISSN: | 1070-664X |
| DOI: | 10.1063/5.0021314 |
| Popis: | Interaction of coherent structures known as blobs in the scrape-off layer of magnetic confinement fusion devices is investigated. Isolated and interacting seeded blobs as well as full plasma turbulence are studied with a two dimensional fluid code. The features of the blobs (size, amplitude, position) are determined with a blob tracking algorithm, which identifies them as coherent structures above a chosen density threshold and compared to a conventional center of mass approach. The agreement of these two methods is shown to be affected by the parameters of the blob tracking algorithm. The benchmarked approach is then extended to a population of interacting plasma blobs with statistically distributed amplitudes, sizes and initial positions for different levels of intermittency. As expected, for decreasing intermittency, we observe an increasing number of blobs deviating from size-velocity scaling laws of perfectly isolated blobs. This is found to be caused by the interaction of blobs with the electrostatic potential of one another, leading to higher average blob velocities. The degree of variation from the picture of perfectly isolated blobs is quantified as a function of the average waiting time of the seeded blobs. Comment: 12 pages, 15 figures |
| Databáze: | OpenAIRE |
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