Commissioning of a first-order matched transition jump at the Brookhaven Relativistic Heavy Ion Collider

Abstract

When accelerating gold ions in the Relativistic Heavy Ion Collider (RHIC) the transition energy must be crossed. For this purpose, RHIC uses a set of correction quadrupoles and special power supplies which can reverse polarity in less than 40 ms. These quadrupoles are used to produce dispersion bumps which increase the transition energy as the beam approaches transition. The change of polarity will then jump the transition energy across the beam energy. This paper describes the commissioning of the RHIC first-order matched transition crossing system.