The Möller Polarized Electron Target is a part of the Hall A Möller Polarimeter, placed on the beamline at the 17.5 m upstream the Main Hall Target. The optical system of the Möller Polarimeter includes three quadrupole and one dipole magnets and with using the Möller detector provides the detection of two electrons in coincidence after Möller scattering of the longitudinal polarized beam electrons on the polarized target electrons. The polarized target electrons are produced in ferromagnetic material that magnetized with using external magnetic field. The cross section asymmetry in the Möller scattering with parallel or unparallel electron spin directions is used for a electron beam polarization measurements. The target polarization value, determined from measurements of saturation curve and hysteresis loop, is used for beam polarization measurement. The Möller Polarized Electron Target includes the vacuum chamber with the ironless magnet in which field two ferromagnetic foils in the nearly saturated states are placed, the moving system for lifting and rotation of target structure relatively electron beam axes, the power supplies and electronic blocks for target moving and the magnetization measurements and software for remote operation and data acquisition and processing.
Last Update: 1 August 1997
