Single beam crab dynamics

It is shown that the eta * crabbing scheme is a relatively simple alternative to the deflection and dispersive cavity schemes. The eta * scheme requires no special RF cavities and introduces no single-beam synchrobetatron coupling mechanism, so the possibility of residual coupling is precluded. Such crabbing is characteristic of all machines, although typically not at the IP. The transverse coupling formalism has been applied to the longitudinal and horizontal planes and have identified elements of the transformation matrix with the angle and height of the beam ellipse. A correspondence between specific full-turn matrix elements and residual synchrobetatron coupling is demonstrated.<>