Abstract
Recently, resonance driving terms were successfully measured in the CERN SPS and the BNL RHIC from the Fourier spectrum of beam position monitor (BPM) data. Based on these measurements a new analysis has been derived to extract truly local observables from BPM data. These local observables are called local resonance terms since they share some similarities with the global resonance terms. In this paper we derive these local terms analytically and present experimental measurements of sextupolar global and local resonance terms in RHIC. Nondestructive measurements of these terms using ac dipoles are also presented.
Highlights
In [1] normal form and Lie algebra techniques were used to describe the motion of a particle confined in an accelerator in the presence of nonlinearities
The generating function terms are directly related to the Hamiltonian terms h1
In the presence of multipoles distributed around the ring, N only depends on those nonlinearities placed between the three beam position monitor (BPM)
Summary
In [1] normal form and Lie algebra techniques were used to describe the motion of a particle confined in an accelerator in the presence of nonlinearities. In [2] the measurement of amplitudes and phases of generating function terms was successfully achieved at two accelerators: the CERN SPS and the BNL RHIC. This measurement together with Eq (3) opens the possibility of measuring magnet strengths. For an ideal uncoupled linear machine, N 0 for any N and for any set of three BPMs. in the presence of multipoles distributed around the ring, N only depends on those nonlinearities placed between the three BPMs. The analytical proof of these statements and the following expressions is given in Appendix A. The measurement of the local terms represents a means of finding lattice imperfections or unexpected multipoles in an accelerator
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
