Fits to data for a stored uncooled polarized deuteron beam

I perform tracking simulations to fit various measurements of the polarization for a stored uncooled polarized deuteron beam, published in the recent paper by Benati et. al (P. Benati {\em et al.}, {\it Phys. Rev. ST Accel. Beams} {\bf 15}, 124202 (2012)). The collaboration kindly sent me datafiles of the polarization measurements, and also pertinent details of the experimental data acquisition procedure. The latter are essential to obtain quantitative fits to the data. I describe my findings and inferences from the data. In some cases I offer alternative interpretations of the data from that given by Benati et. al. I also correct some mistakes in my recent paper (S. R. Mane, {\em Nucl. Inst. Meth.} {\bf 726} 104--112 (2013)).Comment: 24 figure

Spin decoherence rate in a weak focusing all-electric ring

I previously derived the expression for the spin decoherence rate (for orbital and spin motion in the horizontal plane) in a weak focusing all-electric storage ring with a radial field (logarithmic potential, field index $n=0$). Here I generalize the calculation to an arbitrary field index $n\ge0$. I also solve the model for the relativistic Kepler problem (field index $n=1$), where the solution for the orbit is known analytically, and I verify that it confirms the solution from perturbation theory.Comment: 57 pages, 4 figures. v2: I solved the model also for off-energy dispersion orbits. The dispersion orbits are circles and I calculated the spin decoherence rate exactly. v3: I solved the model also for vertical motion, for $n=0$ (logarithmic potential). I have also solved for the spin precession the Kepler problem (inverse square law) exactly; the paper is in press. Extra appendices have been added; in particular, Ivan Koop kindly gave permission to reproduce his elegant analysis of motion in a vertical spiral in a logarithmic potential. v4: Added synchrotron oscillations. arXiv admin note: substantial text overlap with arXiv:1403.502