Double Spin Asymmetry for Exclusive $\pi ^{-}$ Electro-production from Deuterium

At Jefferson Lab, an extensive program of spin structure function experiments is underway in Hall B. We scatter longitudinally polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV from longitudinally polarized NH$_{3}$ and ND$_{3}$ targets. The large acceptance of the CLAS spectrometer enables the detection of multi-particle final states over a large kinematical range in invariant mass $W$ and momentum transfer $Q^{2}$. In particular, we have studied exclusive $\pi ^{-}$ production in the resonance region from the deuteron target, which is sensitive primarily to neutrons in the target. Preliminary results for the double polarization asymmetry for the 2.5 GeV data will be presented.