The IceCube/IceTop air shower experiment

The energy range from the “knee” to the “ankle” on the cosmic ray spectrum is important for understanding the end of the galactic cosmic-ray spectrum and the transition to extra-galactic particles. IceCube with its surface array IceTop will be sensitive to the primary composition through its measurement of the ratio of energetic muons to shower size in coincident events. The combined data from the existing array comprising 9 in-ice strings and 16 surface stations is analyzed to verify its performance for cosmic ray detection. The capability of the full array for cosmic ray composition study is also discussed.