Fluctuations of the rotation angle of the relativistic particle spin in a bent crystal

Bargman-Telegdi type motion equation is linearized using decomposition into a series by a minot parameter, the role of which is played by atomic plane electric field intensity vector fluctuation. As a result of this two equations are derived, one of which describes evolution of average values of spin vector, and the other- the evolution of fluctuation of the corresponding dynamic variables. It is shown that the mean square of spin vector projection fluctuations in directly proportional to the mean square of channeled particle transverse velocity fluctuations and that fast depolarization of a channeled particle beam occurs in stochastically unstable transverse movement region. 8 refs