Analytic fluid theory of beam spiraling in high-intensity cyclotrons
Using a two-dimensional fluid description, we investigate the nonlinear radial-longitudinal dynamics of intense beams in isochronous cyclotrons in the nonrelativistic limit. With a multiscale analysis separating the time scale associated with the betatron motion and the slower time scale associated...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2013
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| Online Access: | http://hdl.handle.net/1721.1/78264 |
| _version_ | 1826215197302325248 |
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| author | Cerfon, Antoine J. Freidberg, Jeffrey P. Parra Fabian, Ignacio Esteban Antaya, T. A. |
| author2 | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Cerfon, Antoine J. Freidberg, Jeffrey P. Parra Fabian, Ignacio Esteban Antaya, T. A. |
| author_sort | Cerfon, Antoine J. |
| collection | MIT |
| description | Using a two-dimensional fluid description, we investigate the nonlinear radial-longitudinal dynamics of intense beams in isochronous cyclotrons in the nonrelativistic limit. With a multiscale analysis separating the time scale associated with the betatron motion and the slower time scale associated with space-charge effects, we show that the longitudinal-radial vortex motion can be understood in the frame moving with the charged beam as the nonlinear advection of the beam by the E×B velocity field, where E is the electric field due to the space charge and B is the external magnetic field. This interpretation provides simple explanations for the stability of round beams and for the development of spiral halos in elongated beams. By numerically solving the nonlinear advection equation for the beam density, we find that it is also in quantitative agreement with results obtained in particle-in-cell simulations. |
| first_indexed | 2024-09-23T16:19:12Z |
| format | Article |
| id | mit-1721.1/78264 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:19:12Z |
| publishDate | 2013 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/782642022-10-02T07:40:21Z Analytic fluid theory of beam spiraling in high-intensity cyclotrons Cerfon, Antoine J. Freidberg, Jeffrey P. Parra Fabian, Ignacio Esteban Antaya, T. A. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Massachusetts Institute of Technology. Plasma Science and Fusion Center Freidberg, Jeffrey P. Parra Fabian, Ignacio Esteban Using a two-dimensional fluid description, we investigate the nonlinear radial-longitudinal dynamics of intense beams in isochronous cyclotrons in the nonrelativistic limit. With a multiscale analysis separating the time scale associated with the betatron motion and the slower time scale associated with space-charge effects, we show that the longitudinal-radial vortex motion can be understood in the frame moving with the charged beam as the nonlinear advection of the beam by the E×B velocity field, where E is the electric field due to the space charge and B is the external magnetic field. This interpretation provides simple explanations for the stability of round beams and for the development of spiral halos in elongated beams. By numerically solving the nonlinear advection equation for the beam density, we find that it is also in quantitative agreement with results obtained in particle-in-cell simulations. 2013-04-03T14:02:00Z 2013-04-03T14:02:00Z 2013-02 2012-10 Article http://purl.org/eprint/type/JournalArticle 1098-4402 http://hdl.handle.net/1721.1/78264 Cerfon, A. J. et al. “Analytic Fluid Theory of Beam Spiraling in High-intensity Cyclotrons.” Physical Review Special Topics - Accelerators and Beams 16.2 (2013). en_US http://dx.doi.org/10.1103/PhysRevSTAB.16.024202 Physical Review Special Topics - Accelerators and Beams Creative Commons Attribution 3.0 http://creativecommons.org/licenses/by/3.0/ application/pdf American Physical Society APS |
| spellingShingle | Cerfon, Antoine J. Freidberg, Jeffrey P. Parra Fabian, Ignacio Esteban Antaya, T. A. Analytic fluid theory of beam spiraling in high-intensity cyclotrons |
| title | Analytic fluid theory of beam spiraling in high-intensity cyclotrons |
| title_full | Analytic fluid theory of beam spiraling in high-intensity cyclotrons |
| title_fullStr | Analytic fluid theory of beam spiraling in high-intensity cyclotrons |
| title_full_unstemmed | Analytic fluid theory of beam spiraling in high-intensity cyclotrons |
| title_short | Analytic fluid theory of beam spiraling in high-intensity cyclotrons |
| title_sort | analytic fluid theory of beam spiraling in high intensity cyclotrons |
| url | http://hdl.handle.net/1721.1/78264 |
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