  We report thermally activated transport resonances for biases below the
superconducting energy gap in a carbon nanotube (CNT) quantum dot (QD) device
with a superconducting Pb and a normal metal contact. These resonances are due
to the superconductor's finite quasi-particle population at elevated
temperatures and can only be observed when the QD life-time broadening is
considerably smaller than the gap. This condition is fulfilled in our QD
devices with optimized Pd/Pb/In multi-layer contacts, which result in
reproducibly large and "clean" superconducting transport gaps with a strong
conductance suppression for subgap biases. We show that these gaps close
monotonically with increasing magnetic field and temperature. The accurate
description of the subgap resonances by a simple resonant tunneling model
illustrates the ideal characteristics of the reported Pb contacts and gives an
alternative access to the tunnel coupling strengths in a QD.
