Synchrotron-sideband snake depolarizing resonances

We recently created a snake depolarizing resonance using an rf solenoid magnet in a ring containing a nearly 100% Siberian snake. We found that the primary snake rf resonance also had two weaker synchrotron sidebands, which are second-order snake resonances; they were probably caused by the energy-dependent strength of the solenoid snake due to the Lorentz contraction of its longitudinal ∫B⋅dl. This was the first observation of an rf synchrotron-sideband depolarizing resonance in the presence of a nearly full Siberian snake.