Hera variable-energy ''mini'' spin rotator and head-on ep collision scheme with choice of electron helicity

The novel scheme of spin rotation and head-on collision in the HERA electron-proton collider is described with emphasis on the means for obtaining a high degree of longitudinal electron polarization of either sign at the interaction points. The variable-energy ''mini'' rotator em...
Ausführliche Beschreibung

The novel scheme of spin rotation and head-on collision in the HERA electron-proton collider is described with emphasis on the means for obtaining a high degree of longitudinal electron polarization of either sign at the interaction points. The variable-energy ''mini'' rotator employed in this scheme is described and discussed, and also the depolarizing effect of radiative spin diffusion and the means to counteract it. The designed scheme covers the whole range of electron energies between 27 and 35 GeV, with a maximum degree of Sokolov-Ternov polarization of 84% at 35 GeV. Ausführliche Beschreibung