Polarized internal targets for electronuclear experiments

Abstract

Polarized internal gas targets represent a unique opportunity for the measurement of spin observables in electro‐nuclear physics. Two measurements will be discussed. First, spin observables have been measured in elastic and quasi‐free scattering of 45, 200, 300, and 415 MeV polarized protons from a polarized 3He internal gas target at the Indiana University Cyclotron Facility Cooler Ring. The data obtained constitute the first measurement of spin correlation parameters using a storage ring with polarized beam and polarized internal gas target. Second, a quasi‐free (e,e’p) experiment using tensor polarized deuterium will be discussed. Here, the goal is the measurement of the S‐ and D‐state parts of the proton spectral function by scattering 700 MeV electrons from an atomic beam source. Large acceptance detectors have been used in both experiments. The internal‐target technique has broad applicability in nuclear and particle physics.