Abstract 1: A Muon Collider requires a reduction of the six-dimensional emittance of the captured muon beam by several orders of magnitude. In this study, we present a new cooling scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we detail its basic features. Then, we establish the theoretical framework to predict and evaluate the performance of ionization cooling channels and discuss its application to our specific case. Finally, we present the first end-to-end simulation of 6D cooling for a Muon Collider and show a notable reduction of the 6D emittance by five orders of magnitude. We find good agreement between simulation and theory.
Abstract 2: Cooling schemes for intense muon beams require the operation of RF cavities in multi-Tesla magnetic fields. This configuration poses some interesting challenges with regard to RF breakdown, surface preparation, instrumentation, etc. Recently, aspects of this technology have successfully been demonstrated at Fermilab's MuCool Test Area (MTA). Specifically, a 201 MHz prototype cavity for the Muon Ionization Cooling Experiment (MICE) was commissioned to its design gradient in a >1 Tesla magnetic field with essentially no RF breakdown -- a significant performance validation for MICE. Furthermore, 805 MHz cavities in the MTA operating in 5 T fields have reached gradients appropriate for the front end of a future muon accelerator.