Wide Band Neutrino Beams with Quadrupole Focusing

For high energy neutrino beams the requirements of large solid angle acceptance and wide bandpass can be achieved with a focusing channel composed of quadrupole cells where each cell is sequentially scaled in aperture, length and field gradient. A formalism for the design of these quadrupole focused neutrino beams with wide bandpass has been developed. The theory will be presented and the results of calculations will be given for some quadrupole focused neutrino beams. Compared to more exotic focusing techniques quadrupoles offer inherent reliability and easy maintenance. The system, which can be used in either long or short spill operation, can also be used as the front end of a muon beam for a facility that would be shared between neutrino and muon experiments. The quadrupole focusing channel does not, however, distinguish between parent particle charge and, therefore, cannot produce a pure neutrino or antineutrino beam.