Optical stochastic cooling for RHIC using optical parametric amplification

Abstract

We propose using an optical parametric amplifier, with a $\ensuremath{\sim}12\text{ }\ensuremath{\mu}\mathrm{m}$ wavelength, for optical-stochastic cooling of $^{79}\mathrm{Au}$ ions in the Relativistic Heavy Ion Collider. While the bandwidth of this amplifier is comparable to that of a Ti:sapphire laser, it has a higher average output power. Its wavelength is longer than that of the laser amplifiers previously considered for such an application. This longer wavelength permits a longer undulator period and higher magnetic field, thereby generating a larger signal from the pickup undulator and ensuring a more efficient interaction in the kicker undulator, both being essential elements in cooling moderately relativistic ions. The transition to a longer wavelength also relaxes the requirements for stability of the path length during ion-beam transport between pickup and kicker undulators.