Speaker
Description
The basic idea to search for the Electric Dipole Moment (EDM) of charged particles in a storage ring was first proposed by the BNL. It assumes observation of the vertical buildup of beam polarization caused by the EDM in a so-called Frozen Spin (FS) lattice. The latter is composed of electrostatic deflectors to keep the momentum of the beam aligned with the direction of a polarization vector. However, this concept can be realized only for particles with positive magnetic anomaly (G), e.g., protons, and requires a lattice to be designed specifically for this purpose.
To perform the EDM experiments with particles characterized with positive and negative G one can use Quasi-Frozen Spin (QFS) lattice. It can be realized on the basis of the existing synchrotron, e.g. NICA, with magnetic arcs and additional E+B elements at straight sections. So, that the net in-plane rotation of the spin-vector in the arcs is compensated in the E+B deflectors.
The main features of the QFS lattice were calculated in the spinor formalism, such as a spin-tune and a direction of the invariant spin axis. As the radial field perturbations play a crucial role in the EDM measurement procedure, the difference of FS and QFS lattices was investigated in this regard.
