  Plasma effect is observed in CCDs exposed to heavy ionizing alpha-particles
with energies in the range 0.5 - 5.5 MeV. The results obtained for the size of
the charge clusters reconstructed on the CCD pixels agrees with previous
measurements in the high energy region (>3.5 MeV). The measurements were
extended to lower energies using alpha-particles produced by (n,alpha)
reactions of neutrons in a Boron-10 target. The effective linear charge density
for the plasma column is measured as a function of energy. The results
demonstrate the potential for high position resolution in the reconstruction of
alpha particles, which opens an interesting possibility for using these
detectors in neutron imaging applications.
