  We present an example of quantum process tomography performed on a single
solid state qubit. The qubit used is two energy levels of the triplet state in
the Nitrogen-Vacancy defect in Diamond. Quantum process tomography is applied
to a qubit which has been allowed to decohere for three different time periods.
In each case the process is found in terms of the $\chi$ matrix representation
and the affine map representation. The discrepancy between experimentally
estimated process and the closest physically valid process is noted.
