Stabilizing effects of chromaticity and synchrotron emission on coupled-bunch transverse dynamics in storage rings

Journal Article · Fri Feb 26 00:00:00 EST 2021 · Physical Review Accelerators and Beams

DOI:https://doi.org/10.1103/PhysRevAccelBeams.24.024402· OSTI ID:1768096

Lindberg, Ryan R.

We present a theory that can compute the transverse coupled-bunch instability growth rates at any chromaticity and for any longitudinal potential provided only that the long-range wakefield varies slowly over the bunch. The theory is expressed in terms of the usual coupled-bunch eigenvalues at zero chromaticity, and when the longitudinal motion is simple harmonic our solution only requires numerical root-finding that is easy to implement and fast to solve; the more general case requires some additional calculations, but is still relatively fast. The theory predicts that the coupled-bunch growth rates can be significantly reduced when the chromatic betatron tune spread is larger than the coupled-bunch growth rate at zero chromaticity. Our theoretical results are compared favorably with tracking simulations for the long-range resistive wall instability, and we also indicate how damping and diffusion from sychrotron emission can further reduce or even stabilize the dynamics.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1768096
• Alternate ID(s): OSTI ID: 1798330
• Journal Information: Physical Review Accelerators and Beams, Journal Name: Physical Review Accelerators and Beams Vol. 24 Journal Issue: 2; ISSN 2469-9888
• Publisher: American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
beam instabilities
relativistic multiple-particle dynamics