Measurement of Tensor Analyzing Powers for Elastic Electron Scattering from a Polarized2H Target Internal to a Storage Ring

We report an absolute measurement of the tensor analyzing powers $T_{20}$ and $T_{22}$ in elastic electron-deuteron scattering at a momentum transfer of $1.6{\mathrm{fm}}^{-1\mathrm{}}$. The novel approach of this measurement is the use of a tensor polarized ${}^2\mathrm{H}$ target internal to an electron storage ring, with in situ measurement of the polarization of the target gas. Scattered electrons and recoil deuterons were detected in coincidence with two large acceptance nonmagnetic detectors. The techniques demonstrated have broad applicability to further measurements of spin-dependent electron scattering.