CBB addresses the transit of the beam from production through acceleration and onward to its target.
The goal is to maximize beam brightness at the beam’s final destination through understanding and controlling the phenomena that can spoil brightness. By ensuring that CBB advances in beam production and beam acceleration are realized in brightness at the target, this theme unifies the center’s research.
Conserve – The more exquisite the beam at the source, the more difficult it is to preserve its brightness as it travels to its destination. A prime example of this problem is space charge (the internal electrostatic repulsion of the electrons in the bunch), which grows in importance for when the bunch is tightly packed. CBB seeks to identify and minimize space charge and other effects for beamlines ranging from X-ray free-electron lasers (FELs) to electron microscopes.
Cool - CBB is developing methods for reducing the transverse momentum spread of beams using optical stochastic cooling (OSC). In this challenging technique, the beam is prompted to emit light in the optical range and then, at the right moment, reabsorb it. A mature cousin, stochastic cooling in the GHz regime, uses a similar technique in a different frequency regime; by comparison, OSC promises faster cooling but success requires much more precise manipulation of the beam. If successful, OSC could increase the luminosity of next-generation particle colliders.
Control - CBB is investigating advanced optimization schemes, including machine learning and parameter reduction techniques, for precision phase-space control of particle accelerator systems.