RF spin resonance strength for stored polarized deuterons.

We studied the ratio of the measured to predicted rf spin resonance strengths $\varepsilon _{FS}$/$^{\ast }\varepsilon _{Bdl}$ for an rf dipole and an rf solenoid using 1.85 GeV/c vertically polarized deuterons at COSY. We measured $\varepsilon _{FS}$ by fitting spin-flipping data to the Froissart-Stora equation, and we calculated each $^{\ast }\varepsilon _{Bdl}$ from each rf magnet's $\smallint $\textit{Bdl.} We found no dependence on the beam's momentum spread or the rf frequency sweep range for either the rf dipole or solenoid. We saw an enhancement of $\varepsilon _{FS}$/$^{\ast }\varepsilon _{Bdl}$ near a 1$^{st}$-order intrinsic resonance for the rf dipole, but no enhancement for the rf solenoid. Except near the intrinsic resonance, the deuteron's $\varepsilon _{FS}$ was very near $^{\ast }\varepsilon _{Bdl}$ for the rf solenoid, but was about 7 times smaller than $^{\ast }\varepsilon _{Bdl }$ for the rf dipole. (Supported by the German BMBF Science Ministry.)