Movable polarized target as a basic equipment for high energy spin physics experiments at the JINR-Dubna accelerator complex

摘要

The Joint Institute for Nuclear Research (JINR) at Dubna has built a new 12 GeV/c accelerator with superconducting magnets (the Nuclotron) which can provide 3-12 GeV/c polarized deuteron beams, with high intensity and good polarization. Using a break-up of accelerated deuterons, it is possible to obtain quasi-monoenergetic polarized neutron and proton beams; to get full benefit to this opportunity, the experiments with polarized beams must be performed in conjunction with polarized proton or deuteron targets. The CEA proposed to use the polarized proton target (PPT), previously used at Fermilab; a collaboration has been set up in order to reconstruct the PPT as a 'movable' polarized target (MPT), which could be easily transported from one beam line to another and to get this unit operating in Russia. A new magnet has to be built and transversal holding coils added. The project phases are presented and three experiments are already proposed: measurements of the difference in the transmission cross sections of polarized neutrons through the PPT when beam and target polarization are parallel or antiparallel; measurements of the spin effects in the backward elastic scattering of transversally deuterons on transversally polarized protons; (phi) meson production with polarized deuteron or proton beams and the PPT. 1 fig. (Atomindex citation 27:014750)