Measurement and correction of third resonance driving term in the RHIC

To further improve the luminosity in polarized proton operation of the relativistic heavy ion collider, correction of the horizontal two-third resonance at store is desirable. The long-lasting coherent beam oscillations, produced by the AC dipole, are used to measure 3Q_x's resonance driving term h₃₀₀₀₀ through the analysis of turn-by-turn beam position data with the algorithm outlined by J. Bengtsson. The resonance driving term h₃₀₀₀₀ can be compensated with the 12 arc chromatic sextupole families. In this article, we will review the technique of h₃₀₀₀₀ resonance driving term's measurement and correction with AC dipole excitation in the RHIC, followed by the preliminary beam experiment results from the RHIC 2006 polarized proton run.