Design and performance of a double-arm 180° spectrometer system for magnetic electron scattering from deuterium

Abstract The design and operation of a double-arm 180° spectrometer system for elastic and inelastic electron scattering from deuterium is described. The system consisted of a chicane of dipole magnets to transport an incident electron beam to a target, an upstream QQQDD spectrometer with a bend angle of 65° to analyze backscattered electrons, a downstream QQQDDDD spectrometer with a bend angle of 66° to detect recoil particles produced at 0°, and a movable beam dump. The large acceptance of the system allowed measurements of the deuteron magnetic elastic B ( Q 2 ) and inelastic W 1 ( v , Q 2 ) structure functions at high momentum transfers. The performance is compared to the predictions of a Monte Carlo simulation program.