Abstract
A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, the spin tune—defined as the number of spin precessions per turn—is given by ( is the Lorentz factor, the gyromagnetic anomaly). At , the deuteron spins coherently precess at a frequency of in the Cooler Synchrotron COSY. The spin tune is deduced from the up-down asymmetry of deuteron-carbon scattering. In a time interval of 2.6 s, the spin tune was determined with a precision of the order , and to for a continuous 100 s accelerator cycle. This renders the presented method a new precision tool for accelerator physics; controlling the spin motion of particles to high precision is mandatory, in particular, for the measurement of electric dipole moments of charged particles in a storage ring.
- Received 1 April 2015
DOI:https://doi.org/10.1103/PhysRevLett.115.094801
© 2015 American Physical Society