A 20-T-HYBRID SOLENOID FOR THE COLLECTION OF PIONS FOR A MUON-COLLIDER

In order to generate intense muon beams for a muon collider, intense p ion beams must be produced in a stationary proton beam target. The pio ns produced by the target must be captured before they can go through phase rotation and decay into muons. A 20 T solenoid with a clear bore of 150 mm can capture particles with a transverse momentum of 225 MeV /c or less. As the captured particles leave the capture solenoid, the magnetic induction is decreased to 5 T while the beam pipe diameter in creases to 300 mm. Phase rotation of the pions and the decay of the pi ons to muons will occur at 5 T. The capture solenoid and the solenoids just downstream from the capture solenoid are subject to high heat lo ads (up to 4.8 MW) and radiation loads from the target. The convention al inner solenoid of the 20 T hybrid magnet system and the water coole d absorber will absorb virtually all of the particle energy from the t arget thus protecting the superconducting part of the solenoid system from excessive radiation heating. This report also describes the solen oid magnets from the capture zone to the solenoidal beam channel withi n the phase rotation RF cavities.