Deep inelastic scattering from polarized deuterons

The spin-dependent structure function of the deuteron, g1D, is calculated within a covariant framework. The off-shell structure of the bound nucleon gives corrections to the convolution model at a level of half a percent for x below 0.7, increasing to more than five percent at larger x. Overall, the dominant source of error comes from the lack of knowledge associated with the deuteron D-state, which may introduce an uncertainty in the neutron spin structure function, g1n, extracted from deuterium data of up to ten percent for x around 0.2.