The balloon-borne experiment "IMAX" launched from Lynn Lake, Canada in 1992 has been used to
measure the cosmic ray proton and helium spectra from 0.2 GeV/n to about 200 GeV/n. The IMAX
apparatus was designed to search for antiprotons and light isotopes using a superconducting magnet
spectrometer with ancillary scintillators, time-of-flight, and aerogel cherenkov detectors. Using
redundant detectors an extensive examination of the instrument efficiency was carried out. We
present here the absolute spectra of protons and helium corrected to the top of the atmosphere
