Preliminary magnetic horn studies in the collection scheme for a neutrino factory

Neutrino factories rely on efficient targeting for a primary proton beam in the 2-16 GeV range and a collection scheme with very large acceptance for the pions produced from the target. A shaped solenoid with a peak field of 20 T tapered to 1.25 T has been suggested. In this note, some initial studies are presented on the use of a magnetic horn at the beginning of the collection scheme: this produces a toroidal magnetic field between the co-axial conductors which can be shaped by designing the form of the inner conductor. Magnetic horns are known to withstand high radiation doses. Preliminary results show that the flux of the pions after a horn could be comparable to that obtained with the suggested solenoid. (6 refs).