The accelerator COSY at the Forschungszentrum Julich provides proton beams
with energies up to 2.6 GeV for medium-energy hadron research. ANKE, an int
ernal target magnetic spectrometer at the internal beam of COSY, is used to
investigate medium effects in proton-nucleus reactions. It has been instal
led in the accelerator ring and commissioned in 1998. As a first experiment
, subthreshold K+-production as been studied in p(12)C collisions.