Particle Production and Radiation Environment at a Neutrino Factory Target Station∗

Efficient production and collection of a large number of muons is needed to make a neutrino factory based on a muon storage ring viable. The results of extensive MARS simulations are reported for Megawatt proton beams on a carbon rod and mercury jet in a 20-T hybrid solenoid, followed by a matching section and decay channel. Beam energy and power in a 2 to 30 GeV range, beam spot size, beam and target tilt angle, target material and dimensions, and capture system parameters are optimized to get maximum muon yields at the end of the decay channel. Other particles transported down the beam line are also studied for the purpose of beam instrumentation. Prompt and residual radiation distributionsare calculated and analysis of target integrity, quench stability and dynamic heat load to the superconducting coils, radiation damage and activation of materials near the beam is performed. Absorption of showers in the direction of a primary beam is considered.