The energy loss spectrum of 180 GeV muons has been measured with the 5.6 m
long finely segmented Module 0 of the ATLAS hadron Tile Calorimeter at the
CERN SPS. The differential probability dP/d nu per radiation length of a fr
actional energy loss nu = DeltaE(mu)/E-mu has been measured in the range 0.
025 less than or equal to nu less than or equal to 0.97: it is compared wit
h theoretical predictions for energy losses due to bremsstrahlung, producti
on of electron-positron pairs. and energetic knock-on electrons. The iron e
lastic form factor correction Delta (el)(Fe) = 1.63 +/-0.17(stat)+/-0.23(sy
st)+/- (0.20)(0.14theor) to muon bremsstrahlung in the region of no screeni
ng of the nucleus by atomic electrons has been measured for the first time,
and is compared with different theoretical predictions.