Abstract
We suggest a new on-axis injection scheme that uses a transverse deflecting rf cavity to kick the incoming beam into an already populated bucket but with a timing offset from the synchronous phase. In a new on-axis injection scheme, two deflecting rf cavities are required: one upstream of the injection point that crabs the stored beam and the other downstream of the injection point that both uncrabs the stored beam and kicks the incoming beam onto the axis of the orbital plane. We present a theoretical analysis and numerical simulations of the stored beam and injected beam with the new injection scheme.
Highlights
The fourth-generation storage ring (4GSR) based on the multibend achromat (MBA) lattice concept may be able to surpass the brightness and coherence that are attained using present third-generation storage rings (3GSRs)
Strong chromatic sextupoles are needed. These nonlinear elements will significantly reduce the dynamic apertures, and this is a great challenge for 4GSR lattice design
Three on-axis injection schemes have been proposed for 4GSR. (i) “Swap-out” injection [9] uses a fast dipole kicker to inject a fresh high-charge beam onto the closed orbit while the stored beam is extracted. (ii) Longitudinal injection with a low-frequency rf system injects a bunch on axis at an rf phase that is far away from the synchrotron phase and with an energy slightly higher than the stored beam; the synchrotron oscillation of the injected beam is damped to the synchrotron phase. (iii) Longitudinal injection with a double-frequency rf system alters two rf voltages to create empty rf buckets that can be taken for onaxis injection; after bunches are injected, the voltage-altering process is reversed, and the injected bunches can be transferred longitudinally to the main rf buckets. These new injection schemes suggest solutions for beam injection into a small dynamics aperture, but the schemes require a tight condition on the injected beam and a kicker that has a very short pulse to avoid disturbing the stored beam
Summary
The fourth-generation storage ring (4GSR) based on the multibend achromat (MBA) lattice concept may be able to surpass the brightness and coherence that are attained using present third-generation storage rings (3GSRs). These nonlinear elements will significantly reduce the dynamic apertures, and this is a great challenge for 4GSR lattice design. (iii) Longitudinal injection with a double-frequency rf system alters two rf voltages to create empty rf buckets that can be taken for onaxis injection; after bunches are injected, the voltage-altering process is reversed, and the injected bunches can be transferred longitudinally to the main rf buckets These new injection schemes suggest solutions for beam injection into a small dynamics aperture, but the schemes require a tight condition on the injected beam and a kicker that has a very short pulse to avoid disturbing the stored beam. The scheme uses two transverse deflecting cavities (TDCs) and thereby eliminates the need to swap out stored beams and implement a short pulse (a few nanoseconds) kicker.
Sign-in/Register to view highlights & summary 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 callDisclaimer: 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.
