A Simulation Study of Linear Coupling Effects and Their Correction in RHIC

Technical Report · Sun Nov 01 04:00:00 EST 1992

DOI:https://doi.org/10.2172/1119370· OSTI ID:1119370

Parzen, G. ^[1]

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1. Brookhaven National Lab. (BNL), Upton, NY (United States)

This paper describes a possible skew quadrupole correction system for linear coupling for the RHIC92 lattice. A simulation study has been done for the correction system. Results are given for the performance of the correction system, and the required strength of the skew quadrupole correctors. An important effect of linear coupling in RHIC is to shift the tune v_x, v_y, sometimes called tune splitting. Most of this tune splitting can be corrected with a two family skew quadrupole correction system. For RHIC92, the same 2 family correction system will work for all likely choices of β*. This was not the case for the RHIC91 lattice where different families of correctors were needed for different β*. The tune splitting described above which is corrected with a 2 family correction system is driven primarily by the v_x $$-$$ v_y harmonic of the skew quadrupole field given by the field multipole a₁. There are several other effects of linear coupling present which are driven primarily by the v_x + v_y harmonics of the skew quadrupole field, a₁. These include the following: 1. A higher order residual tune shift that remains after correction with the 2 family correction system. This tune shift is roughly quadratic in a₁. 2.Possible large changes in the beta functions. 3. Possible increase in the beam size at injection due to the beta function distortion and the emittance distortion at injection. The simulation study computes the magnitude of two of these effects, the higher order residual tune shift and the change in the beta functions.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1119370
• Report Number(s): BNL--102028-2013-IR
• Country of Publication: United States
• Language: English

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