Measuring β^{*} in SuperKEKB with K modulation
SuperKEKB is an asymmetric energy electron positrion collider currently under commissioning in Japan. It aims to achieve a record high luminosity of 8×10^{35} cm^{-2} s^{-1}, for which accurate control of β_{y}^{*} is needed. The advanced final focus system is also relevant for studies related to f...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-01-01
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| Series: | Physical Review Accelerators and Beams |
| Online Access: | http://doi.org/10.1103/PhysRevAccelBeams.23.012803 |
| _version_ | 1818853869276364800 |
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| author | P. Thrane R. Tomás A. Koval K. Ohmi Y. Ohnishi A. Wegscheider |
| author_facet | P. Thrane R. Tomás A. Koval K. Ohmi Y. Ohnishi A. Wegscheider |
| author_sort | P. Thrane |
| collection | DOAJ |
| description | SuperKEKB is an asymmetric energy electron positrion collider currently under commissioning in Japan. It aims to achieve a record high luminosity of 8×10^{35} cm^{-2} s^{-1}, for which accurate control of β_{y}^{*} is needed. The advanced final focus system is also relevant for studies related to future linear colliders, which similarly need to achieve very small beam sizes. To work for SuperKEKB, the K modulation technique is generalized to allow known quadrupole fields between the modulated magnets and the interaction point. Initial measurements taken in HER agree with simulations, and show that K modulation is suitable for measuring the minimum of the β function at the interaction point within 1%, however it is too uncertain to be used for measuring the displacement of the beam waist away from the interaction point. In addition, tune shift equations for a modulated quadrupole are derived without assuming a thin lens perturbation, giving a simple method to calculate the tune shift to second order in the quadrupole strength modulation. |
| first_indexed | 2024-12-19T07:43:40Z |
| format | Article |
| id | doaj.art-5e4df4f0f0e64b09a830fe086c76918b |
| institution | Directory Open Access Journal |
| issn | 2469-9888 |
| language | English |
| last_indexed | 2024-12-19T07:43:40Z |
| publishDate | 2020-01-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Accelerators and Beams |
| spelling | doaj.art-5e4df4f0f0e64b09a830fe086c76918b2022-12-21T20:30:24ZengAmerican Physical SocietyPhysical Review Accelerators and Beams2469-98882020-01-0123101280310.1103/PhysRevAccelBeams.23.012803Measuring β^{*} in SuperKEKB with K modulationP. ThraneR. TomásA. KovalK. OhmiY. OhnishiA. WegscheiderSuperKEKB is an asymmetric energy electron positrion collider currently under commissioning in Japan. It aims to achieve a record high luminosity of 8×10^{35} cm^{-2} s^{-1}, for which accurate control of β_{y}^{*} is needed. The advanced final focus system is also relevant for studies related to future linear colliders, which similarly need to achieve very small beam sizes. To work for SuperKEKB, the K modulation technique is generalized to allow known quadrupole fields between the modulated magnets and the interaction point. Initial measurements taken in HER agree with simulations, and show that K modulation is suitable for measuring the minimum of the β function at the interaction point within 1%, however it is too uncertain to be used for measuring the displacement of the beam waist away from the interaction point. In addition, tune shift equations for a modulated quadrupole are derived without assuming a thin lens perturbation, giving a simple method to calculate the tune shift to second order in the quadrupole strength modulation.http://doi.org/10.1103/PhysRevAccelBeams.23.012803 |
| spellingShingle | P. Thrane R. Tomás A. Koval K. Ohmi Y. Ohnishi A. Wegscheider Measuring β^{*} in SuperKEKB with K modulation Physical Review Accelerators and Beams |
| title | Measuring β^{*} in SuperKEKB with K modulation |
| title_full | Measuring β^{*} in SuperKEKB with K modulation |
| title_fullStr | Measuring β^{*} in SuperKEKB with K modulation |
| title_full_unstemmed | Measuring β^{*} in SuperKEKB with K modulation |
| title_short | Measuring β^{*} in SuperKEKB with K modulation |
| title_sort | measuring β in superkekb with k modulation |
| url | http://doi.org/10.1103/PhysRevAccelBeams.23.012803 |
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