Simulation of the pion decay channel of a neutrino factory

In the pion decay channel of a neutrino factory the particles are transported in a solenoidal magnetic field, a 1.8 T constant field in the CERN reference scenario. Increasing the field strength decreases the transverse emittance of the decay muons. To define a lower limit on the achievable μ emittance, the reference scenario is compared with a study case where pions decay in a field of 20 T. This simulation shows that in any realistic scenario the μ emittance will only be reduced by less than 21% in each transverse plane as compared to the reference scenario, and at the expense of an increase in longitudinal emittance.