The possibilities to preserve and manipulate the deuteron polarization
in colliders are discussed. A small value of deuteron magnetic anomaly (-0.13
comparatively to 1.8 of protons) makes the Siberian Snakes method impractical
for deuterons, but it leaves the possibility to undertake all the measures
on fast and adiabatical crossing of individual spin resonances in a ring
developed and implemented earlier and in recent years at ZGS and AGS for
polarized proton beams. Fast crossing methods are estimated as prospective
for a deuteron energy range below 100 GeV (EPIC collider). At higher energies
(up to 250 GeV of RHIC and 1 TeV of HERA or Tevatron), the adiabatic overcoming
of spin resonances based on beam coherent excitation by static or RF dipoles
above the statistical level (due to imperfections or beam emittance) is estimated
to be efficient. This technique (static dipoles)also can be used in order
to transform the injected and accelerated vertical polarization to the stable
longitudinal one, in energy areas near spin-resonance values. The possibilities
of spin RF-flipping are also estimated, including a possibility of RF-trapped
longitudinal spin at half-integer spin tune. Finally, an exotic scheme of
a twisted spin synchrotron is shown, with the possibility of stable longitudinal
spin in the whole energy range of the storage facility.