A proportional counter operating at high pressure of H2 (and several other gases) is employed as a recoil detector for protons in a n-p scattering experiment. The shape of the current pulse contains information on the density and on the spatial extention of the ionizing track. Thus current and drift time of the pulse is recorded by a wave form analyzer. The first moment of this wave form is used to discriminate point-like events (stopped protons 10-200 KeV) against extended tracks. In the case of elastic n-p scattering (NA6 experiment) a background rejection of 200 can be achieved.