Abstract
Beam halo formation issues are important for the design of high current linear ion accelerators. Various mechanisms can potentially cause beam halo. Some recent studies suggested that Coulomb collisions in the beam bunch can contribute significantly to beam bunch growth and halo development in linear accelerators. Despite the general belief that collisions are not important, it is clear that a rigorous treatment of this question is needed. In an effort to explore this issue in detail we have undertaken an analysis of the effects of Coulomb scattering between ions in a self-consistent spherical bunch.
Highlights
During the last several years, interest has grown in the design of high current linear ion accelerators for a variety of important applications
Our recent contributions to these efforts have been the construction of a model which identifies a major mechanism for transverse halo formation [1], followed by the construction of a self-consistent 6D phase space distribution for studies of halo formation in spheroidal bunches in a linear external confining field [2]
We performed numerical studies with an rms matched, but otherwise non-self-consistent 6D distribution and found a rather rapid transition to a more or less self-consistent distribution with a corresponding small mismatch [3]. In these studies we found that starting with a non-self-consistent distribution altered the parameters for halo formation obtained for the self-consistent distribution only slightly
Summary
During the last several years, interest has grown in the design of high current linear ion accelerators for a variety of important applications. Our objective in this paper is to explore the effect of Coulomb collisions in the beam bunch and to see if this process contributes significantly to beam emittance growth and halo development in linear accelerators. He related the rate for a particle to scatter into the shell around the bunch to the admittance of the accelerator His conclusion was that the effect is important if the acceptance of the machine is small, and. There have been some recent numerical studies which suggest that small angle single Coulomb scattering may not be negligible for spheroidal bunches in a linac [11]. Because of the importance of this question for the design of high current linear ion accelerators, a more rigorous treatment of the effect of single Coulomb collisions is needed. We try to relate our perspective to diffusion caused by many small angle Coulomb collisions as treated by the Fokker-Planck equation
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.
