Helical Muon Beam Cooling Channel Engineering Design

The Helical Cooling Channel (HCC), a novel technique for six-dimensional (6D) ionization cooling of muon beams, has shown considerable promise based on analytic and simulation studies. However, the implementation of this revolutionary method of muon cooling requires new techniques for the integration of high-power RF cavities into the low-temperature superconducting magnets of the HCC. Several SBIR-STTR-developed inventions will be combined in an innovative practical engineering solution for a muon cooling channel suitable for a muon collider. The design will incorporate the HCC, the Helical Solenoid, pressurized RF cavities, and emittance exchange using a continuous absorber and be optimized using G4beamline muon beam cooling simulations. The goal of the project is to optimize beam cooling for maximum collider luminosity while including all known engineering constraints, from material properties to affordable RF power sources and cryogenic loads, and to generate an engineering design of a segment of a channel as a prototype to build and test. A conceptual design for the integration of 805 MHz RF cavities into a 10 T Nb3Sn based HCC test section will be completed. The design will include the pressure and thermal barriers needed within the cryostat to maintain operation of the magnet at 4.2 K while operating the RF and energy absorber at a higher temperature. Commercial Applications and other Benefits: The muon beam cooling channel to be developed in this project will enable a muon collider, the next step toward the energy frontier, or Higgs/Z-factories as the most important benefits. The impact of leapfrogging the LHC to the energy frontier and the importance to the US high energy physics program and associated technology progress would be enormous. Other helical cooling channel examples that can benefit from this project include neutrino factories, scanning for nuclear contraband, studies of material properties with spin resonance techniques, rare muon decay experiments, and muon catalyzed fusion.