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...
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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 |
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doaj-5e4df4f0f0e64b09a830fe086c76918b2020-11-25T02:53:17ZengAmerican 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 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
P. Thrane R. Tomás A. Koval K. Ohmi Y. Ohnishi A. Wegscheider |
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 |
author_facet |
P. Thrane R. Tomás A. Koval K. Ohmi Y. Ohnishi A. Wegscheider |
author_sort |
P. Thrane |
title |
Measuring β^{*} in SuperKEKB with K modulation |
title_short |
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_sort |
measuring β^{*} in superkekb with k modulation |
publisher |
American Physical Society |
series |
Physical Review Accelerators and Beams |
issn |
2469-9888 |
publishDate |
2020-01-01 |
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. |
url |
http://doi.org/10.1103/PhysRevAccelBeams.23.012803 |
work_keys_str_mv |
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