The antimatter research through the earth moon ion spectrometer (ARTEMIS) e
xperiment is described in terms of searching for the moon's shadow in the p
rimary cosmic radiation at TeV energies. Observations were made using the W
hipple 10 m Imaging Atmospheric Cerenkov Telescope, in conjunction with a s
pecial optical filter to suppress unwanted moonlight. Monte Carlo simulatio
ns were used to predict that the magnitude of shadowing based on a pure pro
ton beam would be 1% of the cosmic ray background. Observations and event c
lassification are discussed, and results of a search for shadowing based on
both protons and antiprotons are presented. Atmospheric fluctuations givin
g rise to non-statistical event rates constituted a limiting factor to the
sensitivity of the shadow search as they rivaled or exceeded statistical er
rors. It is demonstrated that the experiment does not have sufficient sensi
tivity to moon shadowing which would allow a search for an antimatter compo
nent in the primary cosmic ray flux at the percent level. Possible future i
mprovements of the technique are discussed. (C) 2001 Elsevier Science B.V.
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