  The discovery of the new family of oxypnictide superconductors, such as
LaFeAsO0.89F0.1, with critical temperature, Tc, over 26 K, has brought new
impetus to the fields of high temperature superconductivity and strongly
correlated electron systems. These materials showed high upper critical fields,
Hc2, which have been estimated to be higher than 55 or 63-65 T in
LaO0.9F0.1FeAs with Tc of 26 K, 70 T in PrFeAsO0.85F0.15, and over 100 T in
SmO0.85F0.15FeAs with Tc of 46 K. The two gap superconductivity proposed for
LaO0.9F0.1FeAs suggests that the Hc2 could be further increased to a
significant extent. This is one of the unique features of the FeAs based new
superconductors. In this work, we show that the Bc2(48 K) = 13 T and the Bc2(0)
value can exceed 230 T in a high pressure fabricated NdO0.82F0.18FeAs bulk
sample with Tc of 51 K. We also demonstrate that the supercurrent density from
1 up to 9 T only drops by a factor of 2-6 for T < 30 K, much weaker than MgB2
and high Tc cuprate superconductors. The very high Bc2 already far surpasses
those of high Tc cuprates, MgB2, and classical low temperature superconductors,
paving the way to use the new NdO0.82F0.18FeAs superconductors for high-field
applications.
