A High Energy , Small Phase - Space Volume Muon Beam

The design and performance of a high-momentum, small phasespace volume muon beam is described. The muons are photoproduced by the bremsstrahlung of electrons incident on a thick target. Pion contamination is reduced to 3 X10 -6 of the muon flux by a 5.5 meter beryllium filter placed immediately after the target. The optical system has two stages of momentum analysis to give an almost dispersion free beam, and a final imaging stage to clean up the tails of the beam distribution. Standard B. N. L. 8648 and 18D72 magnets are used throughout. At 10 GeV/c, the beam yields 1.0 X lo5 p&/second in a phase space volume of 3 x10 -3 cm2 steradians and a momentum band of + 1.5%. (Submitted to Nucl. In&r. and Methods) * Supported by the U. S. Atomic Energy Commission.