Polarised targets for 4π detectors at MAMI

Abstract

The spin, as a fundamental property of a particle, has been a main object of investigation in particle and nuclear physics research in recent decades. Consequently, the investigation of polarisation observables has become more and more important. Nowadays cw beams with high duty cycles are standard technology. In parallel, the development of detectors with full angular acceptance, so called 4π detectors, has kept pace with the accelerator technology to allow for precise determination of the final state of the reaction under investigation. The availability of high speed data acquisition systems has enabled an increase in the luminosities by orders of magnitude. For complete spin investigation, one requires a polarised target in additon to polarised beams and recoil polarimeters. The advent of advanced beam and large acceptance detector technologies has driven the development of highly polarised, full angular acceptance targets.