%0 Journal Article %T Pulsed Magnetic Field Measurements of the Composite Fermion Effective Mass %A D. R. Leadley %A M. van der Burgt %A R. J. Nicholas %A C. T. Foxon %A J. J. Harris %J Physics %D 1995 %I arXiv %R 10.1103/PhysRevB.53.2057 %X Magnetotransport measurements of Composite Fermions (CF) are reported in 50 T pulsed magnetic fields. The CF effective mass is found to increase approximately linearly with the effective field $B^*$, in agreement with our earlier work at lower fields. For a $B^*$ of 14 T it reaches $1.6m_e$, over 20 times the band edge electron mass. Data from all fractions are unified by the single parameter $B^*$ for all the samples studied over a wide range of electron densities. The energy gap is found to increase like $\sqrt{B^*}$ at high fields. %U http://arxiv.org/abs/cond-mat/9508059v2