$K_L$ and Muon Detection System, KLM

The KLM detection system was designed to identify $K_L$'s and muons with high efficiency over a broad momentum range greater than 600 MeV/c. The barrel-shaped region around the interaction point covers an angular range from $45^o$ to in the polar angle and the end-caps in the forward and backward directions extend this range to and  [4,68].