  In this chapter we review the magnetic effects produced by proton irradiation
on graphite, disordered carbon and fullerene films. The advantage of proton
irradiation is twofold: it enables us to make an impurity analysis
simultaneously to the implantation of hydrogen. In this chapter we will review
the main effects obtained after proton irradiation in different carbon-based
structures. This chapter is organized as follows. In section 2 we provide the
main characteristics of our irradiation facility. In this section we show an
example of element analysis obtained in one of the graphite samples used for
the irradiation studies. The irradiation effects are reviewed in section 3.
This section is divided in two main subsections that describe the effects in
oriented graphite and carbon-based thin films. In section 4 we discuss some of
the effects observed after annealing the sample at high temperatures in vacuum
or after leaving it at room temperature for a long period of time.
