  Time- and angle-resolved photoelectron spectroscopy with 13 fs temporal
resolution is used to follow the different stages in the formation of a
Fermi-Dirac distributed electron gas in graphite after absorption of an intense
7 fs laser pulse. Within the first 50 fs after excitation a sequence of time
frames is resolved which are characterized by different energy and momentum
exchange processes among the involved photonic, electronic, and phononic
degrees of freedom. The results reveal experimentally the complexity of the
transition from a nascent non-thermal towards a thermal electron distribution
due to the different timescales associated with the involved interaction
processes.
