The intense low-momentum kaon beam at the Argonne ZGS

The design and operation of the separated 500 MeV/c kaon beam are discussed. The solid-angle momentum acceptance is 90 msr%ΔP/P for a 3 inch long production target. Active beam elements are four quadrupole magnets, and two bending magnets. The beam incorporates a tapered-gap dc separator for mass separation, but utilizes no explicit momentum collimation. Nominal beam length is 400 inches. Using a 2.0 inch long platinum production target, we have measured a 430 MeV/c beam flux of 730K- per 10 11 12.33 GeV/c incident protons for a beam length of 440 inches. In this case, the separated impurity (e-+π-+μ-)/K- is found to be 310. Under normal conditions, we expect 500 MeV/c fluxes of 1950 K- or 13 500 K+ for 1011 12.33 GeV/c incident protons. (Auth.)