Higher order modes of 100 MHz RF cavities and their effect on beam instabilities in the storage ring of Iranian Light Source Facility (ILSF)
Increasing the current, beam lifetime and, the quality of dynamic properties of the stored electron beam in the storage ring are the important purposes of synchrotrons. One of the phenomena affecting the beam quality is the longitudinal and transverse instabilities that increase as the beam current...
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Nuclear Science and Technology Research Institute
2020-12-01
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| Series: | مجله علوم و فنون هستهای |
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| Online Access: | https://jonsat.nstri.ir/article_1166_8133d1499e980970bfdae5b1580c3d4a.pdf |
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| author | S. Ahmadiannamin M. Lamehi Rachti F. Abbasi Davani J. Rahighi |
| author_facet | S. Ahmadiannamin M. Lamehi Rachti F. Abbasi Davani J. Rahighi |
| author_sort | S. Ahmadiannamin |
| collection | DOAJ |
| description | Increasing the current, beam lifetime and, the quality of dynamic properties of the stored electron beam in the storage ring are the important purposes of synchrotrons. One of the phenomena affecting the beam quality is the longitudinal and transverse instabilities that increase as the beam current increases. Longitudinal instability in radiofrequency cavities has the greatest impact due to the high-quality factor of their higher order modes. As a result of these modes, one electron bunch affects the next one and it has a long-range nature. Longitudinal instabilities increase the energy spread and lead to loss of the beam current and reduce the intensity of the output synchrotron radiation. Considering the current and emittance of the Iranian light source which is 400 mA and 270 picometer-radian in the final phase of project, it is important to evaluate the higher order modes and identify the most effective ones. Simulation studies using CST Studio Suit software show that there are 13 monopole modes up to 1500 MHz in the project's 100 MHz radio frequency cavity. Seven modes are dangerous, and two modes at frequencies of 624.67 and 1432.55 MHz, with shunt impedances of 70.8 and 115 kHz, are very effective and must be dealt with in all phases of commissioning. |
| first_indexed | 2024-04-09T14:53:45Z |
| format | Article |
| id | doaj.art-fd5416e548da488ba9538e4f2612d6d8 |
| institution | Directory Open Access Journal |
| issn | 1735-1871 2676-5861 |
| language | fas |
| last_indexed | 2024-04-09T14:53:45Z |
| publishDate | 2020-12-01 |
| publisher | Nuclear Science and Technology Research Institute |
| record_format | Article |
| series | مجله علوم و فنون هستهای |
| spelling | doaj.art-fd5416e548da488ba9538e4f2612d6d82023-05-02T09:07:30ZfasNuclear Science and Technology Research Instituteمجله علوم و فنون هستهای1735-18712676-58612020-12-0141417218110.24200/nst.2021.11661166Higher order modes of 100 MHz RF cavities and their effect on beam instabilities in the storage ring of Iranian Light Source Facility (ILSF)S. Ahmadiannamin0M. Lamehi Rachti1F. Abbasi Davani2J. Rahighi3Physics and Accelerators School, Nuclear Science and Technology Research Institute, AEOI, P.O. Box: 11365-3486, Tehran – IranPhysics and Accelerators School, Nuclear Science and Technology Research Institute, AEOI, P.O. Box: 11365-3486, Tehran – IranRadiation Application Department, Nuclear Engineering Faculty, Shahid Beheshti University, P.O. Box: 1983963113, Tehran – IranIranian Light Source Facility (ILSF), Institute of research in fundamental Sciences (IPM), P.O. Box: 19395-5746, Tehran – IranIncreasing the current, beam lifetime and, the quality of dynamic properties of the stored electron beam in the storage ring are the important purposes of synchrotrons. One of the phenomena affecting the beam quality is the longitudinal and transverse instabilities that increase as the beam current increases. Longitudinal instability in radiofrequency cavities has the greatest impact due to the high-quality factor of their higher order modes. As a result of these modes, one electron bunch affects the next one and it has a long-range nature. Longitudinal instabilities increase the energy spread and lead to loss of the beam current and reduce the intensity of the output synchrotron radiation. Considering the current and emittance of the Iranian light source which is 400 mA and 270 picometer-radian in the final phase of project, it is important to evaluate the higher order modes and identify the most effective ones. Simulation studies using CST Studio Suit software show that there are 13 monopole modes up to 1500 MHz in the project's 100 MHz radio frequency cavity. Seven modes are dangerous, and two modes at frequencies of 624.67 and 1432.55 MHz, with shunt impedances of 70.8 and 115 kHz, are very effective and must be dealt with in all phases of commissioning.https://jonsat.nstri.ir/article_1166_8133d1499e980970bfdae5b1580c3d4a.pdfhigher order modes100 mhz rf cavitylongitudinal instabilitiesshunt impedance |
| spellingShingle | S. Ahmadiannamin M. Lamehi Rachti F. Abbasi Davani J. Rahighi Higher order modes of 100 MHz RF cavities and their effect on beam instabilities in the storage ring of Iranian Light Source Facility (ILSF) مجله علوم و فنون هستهای higher order modes 100 mhz rf cavity longitudinal instabilities shunt impedance |
| title | Higher order modes of 100 MHz RF cavities and their effect on beam
instabilities in the storage ring of Iranian Light Source Facility (ILSF) |
| title_full | Higher order modes of 100 MHz RF cavities and their effect on beam
instabilities in the storage ring of Iranian Light Source Facility (ILSF) |
| title_fullStr | Higher order modes of 100 MHz RF cavities and their effect on beam
instabilities in the storage ring of Iranian Light Source Facility (ILSF) |
| title_full_unstemmed | Higher order modes of 100 MHz RF cavities and their effect on beam
instabilities in the storage ring of Iranian Light Source Facility (ILSF) |
| title_short | Higher order modes of 100 MHz RF cavities and their effect on beam
instabilities in the storage ring of Iranian Light Source Facility (ILSF) |
| title_sort | higher order modes of 100 mhz rf cavities and their effect on beam instabilities in the storage ring of iranian light source facility ilsf |
| topic | higher order modes 100 mhz rf cavity longitudinal instabilities shunt impedance |
| url | https://jonsat.nstri.ir/article_1166_8133d1499e980970bfdae5b1580c3d4a.pdf |
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