Using beryllium as a selective hadron filter, the kaon fraction of a positively charged 200 GeV/c secondary beam has been increased from 3% to ∼15% without an appreciable effect on tagging efficiency.
Bibliographical noteFunding Information:
We thank Drs. A. Brenner, T. Groves, E. Malamud, J. Peoples, T. Yamanouchi and their staffs at Fermi-lab for their continued support. This work was supported in part by the National Science Foundation and by the Department of Energy.