Electron and muon densities in cosmic rays measured at $L_{3}$+C

The L/sub 3/+C experiment at CERN has been extended with an air shower scintillator array. The combination of the measurement of the shower particle density with the precision measurement of cosmic ray muons in the L/sub 3/ spectrometer provides a new tool to study the physics of cosmic rays. Correlations between the electron-photon and the muon components of air showers observed with large area detectors are known to provide information about the composition of the primary cosmic ray flux. For this, new observations on the energy spectrum of muons over a large energy range and the multiplicity distribution of high energy muons are needed. We present here the details of the L /sub 3/+C experiment relevant for such studies and discuss some preliminary observations. (6 refs).