[en] An internal polarized ³He target is currently under construction at MIT. The target will be used in the HERMES experiment, which will measure the spin dependent deep inelastic scattering from the neutron and proton by the scattering of 30-35 GeV longitudinally polarized electrons from polarized hydrogen, deuterium, and ³He in the East Hall of HERA. The target is based on the technique of metastability exchange laser optical pumping. ³He nuclei are introduced into a glass cell, where they are polarized with high intensity laser light. The nuclei then migrate out of the glass cell into a windowless storage cell where they are allowed to interact with the beam before being pumped away. Two pairs of Helmholtz coils will be employed to create a magnetic field which will orient the ³He nuclei along one of two axes. The storage cell will be cryogenically cooled to 15K, giving a density of 10¹⁵ atoms/cm². Target polarizations of over 50% are expected. The present status of the HERMES target will be discussed

[en] We describe an internal polarized ³He target under construction which will be used in several electron storage ring experiments. The target is based on the technique of metastability exchange laser optical pumping, where the polarized atoms flow into a cryogenically-cooled storage cell. This novel technique allows for high precision measurements where the beam interacts with the pure atomic species. Both the HERMES experiment at DESY and the BLAST detector at the MIT Bates Laboratory will use the polarized ³He target in their measurements. Details of the target system, including the provisions needed to incorporate the target into the electron storage ring, are presented

[en] The temperature dependence of the polarization of ³He atoms in an internal target cell has been studied. Metastable optically pumped polarized ³He atoms with typical polarization values of 40% were injected into a thin-walled aluminum cell of 40 cm length and a 29.0 x 9.8 mm² elliptical cross-section. The cell temperature was varied between 5 and 85 K. The polarization inside the target cell was measured via an asymmetry in the ³vector(He)(d,p)⁴He reaction at a deuteron energy of 4 MeV. An exponential decrease of the polarization was found for temperatures less than 15 K. For a temperature of ∝6 K a polarization consistent with zero was measured. (orig.)

[en] We present the results of a measurement of the spin-dependent asymmetry in ³H rvec e(rvec e,e') inelastic scattering at kinematics on the low-energy transfer side of the quasielastic peak, including the region near the breakup threshold. Comparison with existing calculations based upon the plane wave impulse approximation shows significant deviation between the data and the model near the breakup threshold. Good agreement between data and theory is seen at higher energy transfer

[en] We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized ³He target. The neutron magnetic form factor Gⁿ_M has been extracted from the measured asymmetry based on recent PWIA calculations using spin-dependent spectral functions. Our determination of Gⁿ_M at Q²=0.19 (GeV/c)² agrees with the dipole parametrization. This experiment represents the first measurement of the neutron magnetic form factor using spin-dependent electron scattering

[en] We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized ³He target. The neutron magnetic form factor Gⁿ_M has been extracted from the measured asymmetry based on recent PWIA calculations using spin-dependent spectral functions. This experiment represents the first measurement of the neutron magnetic form factor using spin-dependent electron scattering. copyright 1995 American Institute of Physics

[en] We describe an internal polarized ³He target currently under construction which will be used in several electron storage ring experiments. The target is based on the technique of metastability exchange laser optical pumping, where the polarized atoms flow into a cryogenically-cooled storage cell. This novel technique allows for high precision measurements where the beam interacts with the pure atomic species. Both the HERMES experiment at DESY and the BLAST detector at the MIT Bates Laboratory will use the polarized ³He target in their measurements. Details of the target system, including the provisions needed to incorporate the target into the electron storage ring, are presented. (orig.)

[en] We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized ³He target. The neutron magnetic form factor Gⁿ_M has been extracted from the measured asymmetry based on recent PWIA calculations using spin-dependent spectral functions. This work represents the first measurement of Gⁿ_M using spin-dependent electron scattering. copyright 1995 American Institute of Physics

[en] We report measurements of spin correlations and analyzing powers in ³ rvec He(rvec p,2p) and ³ rvec He(rvec p,pn)quasielastic scattering as a function of momentum transfer and missing momentum at 197 MeV using a polarized internal target at the Indiana University Cyclotron Facility Cooler Ring. At sufficiently high momentum transfer we find ³ rvec He(rvec p,pn) spin observables are in good agreementwith free p-n scattering observables, and therefore that ³ rvec He can serve as a good polarizedneutron target. The extracted polarizations of nucleons in ³ rvec He at low missing momentumare consistent with Faddeev calculations

[en] The transverse-longitudinal asymmetry A_TL' in ³He→(rvec e,e') quasielastic scattering at momentum transfer Q²=0.14(GeV/c)² has been measured to be 1.52±0.55(stat)±0.15(syst)%. The plane wave impulse approximation (PWIA) prediction for this measurement ranges from 2.1% to 2.9%, where the variation is due to uncertainty in the initial state wave function, nucleon form factors, and off-shell prescription. The data may suggest a suppression with respect to the PWIA, which has also been observed for the unpolarized longitudinal response function