Phase Locking the Spin Precession in a Storage Ring
Abstract
This Letter reports the successful use of feedback from a spin polarization measurement to the revolution
frequency of a 0.97 GeV/c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY)
storage ring in order to control both the precession rate (≈121 kHz) and the phase of the horizontal
polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the
rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to
manipulate the polarization. In particular, the rotation rate shows a sinusoidal function of the horizontal
polarization phase (relative to the rf solenoid), which was controlled to within a 1 standard deviation range
of σ = 0.21 rad. The minimum possible adjustment was 3.7 mHz out of a revolution frequency of 753 kHz,
which changes the precession rate by 26 mrad/s. Such a capability meets a requirement for the use of
storage rings to look for an intrinsic electric dipole moment of charged particles.
N. Hempelmann et al. (JEDI Collaboration),
Physical Review Letters 119 (2017) 014801.
DOI: 10.1103/PhysRevLett.119.014801
Download
Click on the icon to download the corresponding file.
Download Adobe PDF version (360669 Bytes).
Go Back to the reprint server.
Go Back to the home page.
This page is maintained by Kyoko Makino. Please contact her if there are any problems with it.