Abstract
Future light sources aim at achieving a diffraction limited photon beam both in the horizontal and vertical planes. High gradient quadrupoles and strong chromaticity correction sextupoles in a corresponding ultra-low emittance ring may restrict the physical and dynamic aperture of the storage ring such that off-axis injection and accumulation may become impossible. We propose a longitudinal injection scheme, i.e., injecting an electron bunch onto the closed orbit with a time offset with respect to the circulating bunches. The temporal separation enables a pulsed dipole kicker to situate the injected bunch transversely on-axis without disturbing the circulating bunches if the pulse length is shorter than the bunch spacing. The injected bunch is finally merged to a circulating bunch through synchrotron radiation damping. We present the scheme in detail and its application to the lattice of the MAX IV 3 GeV storage ring. The requirements and feasibility of the pulsed dipole kicker are also discussed.4 MoreReceived 20 August 2014DOI:https://doi.org/10.1103/PhysRevSTAB.18.020701This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical Society
Highlights
The performance of light sources has been progressively approaching one of its ultimate goals, i.e., achieving a double plane diffraction limited photon beam
In this paper we present another transparent injection scheme for reduced-aperture machines—longitudinal injection—where the injected bunch is longitudinally separate from the circulating bunches, i.e., injected with a time offset
We present an application of the longitudinal injection scheme to the lattice of the MAX IV 3 GeV storage ring [10] with numerical simulations
Summary
The performance of light sources has been progressively approaching one of its ultimate goals, i.e., achieving a double plane diffraction limited photon beam. The injected bunch is transversely separate from the circulating bunches, and it is referred to as off-axis injection It requires a relatively large physical and dynamic aperture of the ring to capture the injected beam because the transverse separation must be larger than the septum thickness. Though this scheme is in principle transparent to the circulating bunches, the kicker bump introduces adverse disturbance to the photon beam even when intensive efforts are made to close the orbit bump Another important goal is to avoid such a kicker bump. The bunch can be injected transversely onaxis using a pulsed dipole kicker because the separation is realized in the longitudinal phase space. The injection scheme that we present is based on the separation in the longitudinal phase space but adapted to modern light sources: it requires neither a kicker bump nor a multiple rf system.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Physical Review Special Topics - Accelerators and Beams
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
