Radiative Spin Polarization in High Energy Storage Rings

This book presents a comprehensive overview of radiative spin polarization in high energy storage rings. The spins of electrons and/or positrons circulating in high energy storage rings become spontaneously polarized because the spin couples to the photons emitted in synchrotron radiation. This book explains the fundamental physics of radiative spin polarization from the ground up, exhibiting how the principles of relativity, quantum mechanics, electrodynamics and statistical mechanics contribute at every step of the calculation. The author has been an authority on the subject for four decades, including developing the first algorithm to systematically calculate the so-called ``depolarizing spin resonances'' to all orders. The text begins with an historical introduction to synchrotron radiation and the relevant quantum theory. The idealized model of motion in a uniform vertical magnetic field is treated in detail, to introduce basic concepts. The connection to research in astrophysics is also noted. Later chapters treat the significant additional physics introduced by the motion of the particles in the inhomogeneous magnetic fields of real storage rings, and the especially the subtleties of the statistical mechanics involved. A full chapter is devoted to the principal formula (the Derbenev-Kondratenko formula), which is derived and explained in detail. Later chapters establish the connection to the so-called ``Unruh effect'' for motion in accelerated reference frames, also the connection of the spin precession to topological quantum mechanics (Berry's phase and the Aharanov-Anandan phase) and practical computational formalisms to implement the theoretical formulas.