Brookhaven Lecture

The Relativistic Heavy Ion Collider (RHIC) has been accelerating ion and proton beams for just over a decade. Collisions between high energy particles are enabled when bunches of particles in each of RHIC's two superconducting rings are guided, focused, and accelerated to nearly the speed of light and then made to collide with similarly accelerated bunches travelling in the opposite direction. To ensure highest collision rates, the beam sizes, if properly maintained during acceleration, are electromagnetically squeezed down to the width of a human hair and then these two-foot-long bunches are made to collide head-on so maximizing the overlap between bunches. Key to achieving ultimate performance are adjustments of the collider system parameters based on continuous precision measurements of the beam's properties. In the past few years, developments have led to improved measurements of the most critical beam properties which in turn has allowed feedback-based beam control â€" a world's first in high energy hadron colliders. The essential achievements and impact on RHIC performance will be presented in this Brookhaven Lecture titled "Keeping RHIC's Beam Tight and the Orbit Right: Precision Control of Accelerating Beams."