  Recently, magnetic order in highly oriented pyrolytic graphite (HOPG) induced
by proton broad- and microbeam irradiation was discovered. Theoretical models
propose that hydrogen could play a major role in the magnetism mechanism. We
analysed the hydrogen distribution of pristine as well as irradiated HOPG
samples, which were implanted to micrometer-sized spots as well as extended
areas with various doses of 2.25 MeV protons at the Leipzig microprobe LIPSION.
For this we used the sensitive 3D hydrogen microscopy system at the Munich
microprobe SNAKE. The background hydrogen level in pristine HOPG is determined
to be less than 0.3 at-ppm. About 4.8e15 H-atoms/cm^2 are observed in the
near-surface region (4 um depth resolution). The depth profiles of the implants
show hydrogen located within a confined peak at the end of range, in agreement
with SRIM Monte Carlo simulations, and no evidence of diffusion broadening
along the c-axis. At sample with microspots, up to 40 at-% of the implanted
hydrogen is not detected, providing support for lateral hydrogen diffusion.
